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@ -10,479 +10,494 @@ include ../../../_includes/_util-fns
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in JavaScript and Dart by selecting either of those languages from the combo-box in the banner.
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.l-main-section
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:marked
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## See It Run!
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Running the [live example](/resources/live-examples/quickstart/ts/plnkr.html)
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is the quickest way to see an Angular 2 app come to life.
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Clicking that link fires up a browser, loads the sample in [plunker](http://plnkr.co/ "Plunker"),
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and displays a simple message:
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figure.image-display
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img(src='/resources/images/devguide/quickstart/my-first-app.png' alt="Output of quickstart app")
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:marked
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Here is the file structure:
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code-example(format="").
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angular2-quickstart
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├─ app
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│ ├── app.component.ts
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│ └── boot.ts
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├─ index.htm
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└─ license.md
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:marked
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Functionally, it's an `index.html` and two TypeScript files in an `app/` folder.
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We can handle that!
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Of course we won't build many apps that only run in plunker.
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Let's follow a process that's closer to what we'd do in real life.
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1. Set up our development environment
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1. Write the Angular root component for our main app
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1. Bootstrap it to take control of the main web page
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1. Write the main page (`index.html`)
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.l-sub-section
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:marked
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## The shortest, quickest ...
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Let's put something on the screen in Angular 2 as quickly as we can.
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.l-sub-section
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:marked
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While we are about to describe steps to take on your development machine,
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you could take these same steps in an interactive, online coding environment
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such as [plunker](http://plnkr.co/ "Plunker"). You won't have to
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install a static server to run the app there.
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If you like what you see - and we think you will - you can repeat this
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exercise on your own machine later.
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:marked
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**Create a new folder** to hold our application project, perhaps like this:
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```
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mkdir angular2-quickstart
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cd angular2-quickstart
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```
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.l-main-section
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:marked
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## Our first Angular component
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**Add a new file** called **`app.ts`** and paste the following lines:
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+makeExample('quickstart/ts/src/app/app.ts', null, 'app.ts')
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:marked
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We've just defined an Angular 2 **component**,
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one of the most important Angular 2 features.
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Components are our primary means of creating application views
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and supporting them with application logic.
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Ours is an empty, do-nothing class named `AppComponent`.
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It would expand with properties and application
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logic when we're ready to build a substantive application.
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Above the class we see the `@Component` decoration.
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.l-sub-section
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:marked
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The `@` symbol before the method name identifies `Component` as a decoration.
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A "decoration" is a TypeScript language feature
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for creating metadata about the class. Angular finds this metadata
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in the transpiled JavaScript and responds appropriately.
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:marked
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`@Component` tells Angular that this class *is an Angular component*.
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The configuration object passed to the `@Component` method has two
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fields, a `selector` and a `template`.
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The `selector` specifies a CSS selector for a host HTML element named `my-app`.
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Angular creates and displays an instance of our `AppComponent`
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wherever it encounters a `my-app` element.
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The `template` field is the component's companion template
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that tells Angular how to render a view.
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Our template is a single line of HTML announcing "My First Angular App".
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The `bootstrap` method tells Angular to start the application with this
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component at the application root.
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We'd be correct to guess that someday our application will
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consist of more components arising in tree-like fashion from this root.
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In the top line we imported the `Component` and `bootstrap` symbols
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from the Angular 2 library. That's the way we do things now.
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We no longer expect to find our code or any library code in a global namespace.
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We `import` exactly what we need, as we need it, from named file and library resources.
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We really can build the QuickStart from scratch in five minutes
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if we follow the instructions and ignore the commentary.
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Most of us will be interested in the "why" as well as the "how" and that will take longer.
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:marked
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.l-main-section
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:marked
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|
## Development Environment
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We'll need a place to stand (the application project folder), some libraries,
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some TypeScript configuration and the TypeScript-aware editor of your choice.
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### Create a new project folder
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code-example(format="").
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mkdir angular2-quickstart
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cd angular2-quickstart
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:marked
|
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|
### Add the libraries we need
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We recommend the **npm** package manager for acquiring and managing our development libraries.
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.l-sub-section
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:marked
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|
## Add `index.html`
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**Create** an `index.html` file.
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**Paste** the following lines into it ... and we'll discuss them:
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|
+makeExample('quickstart/ts/src/index.1.html', null, 'index.html')
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|
Don't have npm?
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|
|
[Get it now](https://docs.npmjs.com/getting-started/installing-node "Installing Node.js and updating npm")
|
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|
because we're going to use it now and repeatedly throughout this documentation.
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:marked
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|
Add a **package.json** file to the project folder and copy/paste the following:
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|
+makeJson('quickstart/ts/package.1.json', null, 'package.json')(format=".")
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|
.l-sub-section
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:marked
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|
We see three noteworthy sections of HTML:
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Itching to know the details? We explain in the [appendix below](#package-json)
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:marked
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Install these packages by opening a terminal window (command window in Windows) and
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|
running this npm command.
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|
code-example(format="").
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npm install
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:marked
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|
.l-sub-section
|
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|
:marked
|
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|
A few scary messages in red may appear in the console. Ignore them.
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|
What matters is is if it finishes cleanly. If it does, continue on.
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|
If it doesn't, time to stop and find out why.
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:marked
|
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|
|
### Configure TypeScript
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|
1. We load JavaScript libraries from the web.
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|
Let's take them on faith without further discussion.<br/><br/>
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2. We configure something called `System` and ask it to import the
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|
application file with our `AppComponent` that we just wrote.
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|
`System` is the module loader (from the `system.js` library),
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|
a tool that can `import` code;
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|
|
remember the `import` statement in our `AppComponent`?
|
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|
We're also asking `system.js` to "transpile" (AKA "compile") our
|
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|
TypeScript source code into JavaScript ... right here in the browser.<br/><br/>
|
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|
3. We note the `<my-app>` tag in the `<body>`.
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|
|
That's the custom HTML element we identified in the `@Component` decoration
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|
|
adorning our `AppComponent` class.
|
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|
|
We must guide the TypeScript compiler with very specific settings.
|
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|
|
|
|
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|
|
Add a **tsconfig.json** file to the project folder and copy/paste the following:
|
|
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|
|
+makeJson('quickstart/ts/tsconfig.1.json', null, 'tsconfig.json')(format=".")
|
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|
|
|
.l-sub-section
|
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|
|
|
:marked
|
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|
|
We explore the `tsconfig.json` in an [appendix below](#tsconfig)
|
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|
|
:marked
|
|
|
|
|
**We're all set.** Let's write some code.
|
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|
|
|
|
|
|
|
.l-main-section
|
|
|
|
|
:marked
|
|
|
|
|
## Our First Angular Component
|
|
|
|
|
|
|
|
|
|
The *Component* is the most fundamental of Angular concepts.
|
|
|
|
|
A component manages a view - a piece of the web page where we display information
|
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|
|
|
to the user and respond to user feedback.
|
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|
|
|
|
|
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|
|
Technically, a component is a class that controls a view template.
|
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|
|
We'll write a lot of them as we build Angular apps. This is our first attempt
|
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|
|
so we'll keep it ridiculously simple.
|
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|
|
|
|
|
|
|
### Create an application source sub-folder
|
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|
|
|
|
|
|
|
|
We like to keep our application code in a sub-folder off the root called `app/`.
|
|
|
|
|
Execute the following command in the console window.
|
|
|
|
|
code-example(format="").
|
|
|
|
|
mkdir app
|
|
|
|
|
cd app
|
|
|
|
|
:marked
|
|
|
|
|
### Add the component file
|
|
|
|
|
Now add a file named **app.component.ts** and paste the following lines:
|
|
|
|
|
+makeExample('quickstart/ts/app/app.component.ts', null, 'app/app.component.ts')(format=".")
|
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|
|
|
|
|
|
|
|
:marked
|
|
|
|
|
### The Component class
|
|
|
|
|
At the bottom of the file is an empty, do-nothing class named `AppComponent`.
|
|
|
|
|
When we're ready to build a substantive application,
|
|
|
|
|
we can expand this class with properties and application logic.
|
|
|
|
|
Our `AppComponent` class is empty because we don't need it to do anything in this QuickStart.
|
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|
|
|
|
|
|
|
|
We do **export** the `AppComponent` class. Our component is a module.
|
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|
|
Another part of the application will import our module and put it to work.
|
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|
|
|
|
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|
|
### Modules
|
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|
|
Angular apps are modular. They consist of many files each dedicated to a purpose.
|
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|
|
Our `app.component` file is both the home and the name of the module that
|
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|
|
provides the application's root component — its top level component.
|
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|
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|
|
A more sophisticated application would have child components that descended from
|
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|
|
`AppComponent` in a visual tree.
|
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|
|
Quickstart isn't sophisticated; one component is all we need.
|
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|
|
Yet modules play a fundamental organizational role in even this small app.
|
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|
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|
|
Modules rely on other modules. In TypeScript Angular apps, when we need something
|
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|
|
provided by another module, we import it.
|
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|
|
|
|
|
|
|
|
Angular is a collection of library modules.
|
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|
|
Each library is a module made up of several, related feature modules.
|
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|
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|
|
The `angular2/core` library is the primary module and we need something from it.
|
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|
|
We need the `Component`function.
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|
When we want something from a module, we `import` it.
|
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|
|
We begin by importing the `Component` symbol from Angular.
|
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|
|
+makeExample('quickstart/ts/app/app.component.ts', 'import')(format=".")
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|
:marked
|
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|
|
Then we use it to define metadata about the `AppComponent`
|
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|
|
|
|
|
|
|
### Component Metadata
|
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|
|
A class becomes an Angular component when we give it metadata.
|
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|
|
Angular needs the metadata to understand how to construct the view
|
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|
|
and how the component interacts with other parts of the application.
|
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|
|
We define a component's metadata with the `Component` function.
|
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|
|
In TypeScript we apply that function to the class as a *decorator*
|
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|
|
by prefixing it with the **@** symbol and invoking it
|
|
|
|
|
just above the component class:
|
|
|
|
|
+makeExample('quickstart/ts/app/app.component.ts', 'metadata', 'app/app.component.ts (metadata)')
|
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|
|
|
:marked
|
|
|
|
|
`@Component` tells Angular that this class *is an Angular component*.
|
|
|
|
|
The configuration object passed to the `@Component` method has two
|
|
|
|
|
fields, a `selector` and a `template`.
|
|
|
|
|
|
|
|
|
|
The `selector` specifies a CSS selector for a host HTML element named `my-app`.
|
|
|
|
|
Angular creates and displays an instance of our `AppComponent`
|
|
|
|
|
wherever it encounters a `my-app` element in the host HTML.
|
|
|
|
|
|
|
|
|
|
.alert.is-helpful
|
|
|
|
|
:marked
|
|
|
|
|
## Run it!
|
|
|
|
|
|
|
|
|
|
We need a static file server to serve our application to the browser.
|
|
|
|
|
|
|
|
|
|
.l-sub-section
|
|
|
|
|
:marked
|
|
|
|
|
Don't have a static file server handy? Let's install one of our favorites
|
|
|
|
|
called [live-server](https://www.npmjs.com/package/live-server "Live-server")
|
|
|
|
|
with the **npm package manager**.
|
|
|
|
|
|
|
|
|
|
Don't have npm?
|
|
|
|
|
[Get it now](https://docs.npmjs.com/getting-started/installing-node "Installing Node.js and updating npm")
|
|
|
|
|
because we're going to use it now and repeatedly throughout this documentation.
|
|
|
|
|
|
|
|
|
|
Once you have `npm` installed, open a terminal window and enter
|
|
|
|
|
|
|
|
|
|
pre.prettyprint.lang-bash
|
|
|
|
|
code npm install -g live-server
|
|
|
|
|
Remember the `my-app` selector! We'll need that information when we write our `index.html`
|
|
|
|
|
:marked
|
|
|
|
|
The `template` property holds the component's companion template.
|
|
|
|
|
A template is a form of HTML that tells Angular how to render a view.
|
|
|
|
|
Our template is a single line of HTML announcing "My First Angular App".
|
|
|
|
|
|
|
|
|
|
Now we need something to tell Angular to load this component.
|
|
|
|
|
|
|
|
|
|
### Give it the boot
|
|
|
|
|
|
|
|
|
|
Add a new file , `boot.ts`, to the `app/` folder as follows:
|
|
|
|
|
+makeExample('quickstart/ts/app/boot.ts', null, 'app/boot.ts')(format=".")
|
|
|
|
|
:marked
|
|
|
|
|
We need two things to launch the application:
|
|
|
|
|
1. Angular's browser `bootstrap` function
|
|
|
|
|
1. The application root component that we just wrote.
|
|
|
|
|
|
|
|
|
|
We import both. Then we call `bootstrap`, passing in the **root component type**,
|
|
|
|
|
`AppComponent`.
|
|
|
|
|
|
|
|
|
|
.l-sub-section
|
|
|
|
|
:marked
|
|
|
|
|
Open a terminal window and enter
|
|
|
|
|
|
|
|
|
|
pre.prettyprint.lang-bash
|
|
|
|
|
code live-server
|
|
|
|
|
:marked
|
|
|
|
|
In a few moments, a browser tab should open and display
|
|
|
|
|
|
|
|
|
|
figure.image-display
|
|
|
|
|
img(src='/resources/images/devguide/quickstart/my-first-app.png' alt="Output of quickstart app")
|
|
|
|
|
|
|
|
|
|
:marked
|
|
|
|
|
Congratulations! We are in business.
|
|
|
|
|
|
|
|
|
|
.alert.is-helpful
|
|
|
|
|
:marked
|
|
|
|
|
If you see `Loading...` displayed instead, see the
|
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|
[Browser ES6 support appendix](#es6support).
|
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### bootstrapping is platform-specific
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Note that `bootstrap` function comes from a *different library*, `angular2/platform/browser`.
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Most Angular applications run only in a browser and we'll call the bootstrap function from
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this library most of the time.
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It is possible to load a component in a different enviroment such as we might do
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if we wished to render the first page of our application on the server.
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That would require a different kind of bootstrap function.
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:marked
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We've asked Angular to launch the app in a browser with our component at the root.
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Where will Angular put it?
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.l-main-section
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:marked
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## What's wrong with this?
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:marked
|
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## Add the `index.html`
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Angular displays our application in a specific location on our `index.html`.
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It's time to create that file.
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We were up and running in a hurry and we could explore Angular
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in this manner for quite some time.
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We won't put our `index.html` in the `app/` folder.
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We'll locate it **up one level, in the project root folder**.
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code-example(format="").
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cd ..
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:marked
|
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Now create the`index.html` file and paste the following lines:
|
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|
+makeExample('quickstart/ts/index.html', null, 'index.html')
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:marked
|
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|
There are three noteworthy sections of HTML:
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For a number of reasons this isn't a good approach for building an application.
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<!-- TODO The formatting here is a little weird. Should improve readability. -->
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1. We load the JavaScript libraries we need.<br/>
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* Transpiling TypeScript in the browser becomes tediously slow when our
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app grows beyond a few files. We certainly won't do that in production. We should learn to
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|
compile locally and push the generated JavaScript to the server. We'll need some tools for that.
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2. We configure something called `System` and ask it to import the
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boot file we just wrote.
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* Downloading JavaScript libraries from the web is OK for demos but
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it slows our development. Every time our app reloads, it must refetch these libraries.
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|
Don't count on browser caching.
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Our debugging and live-reload techniques will bust the browser cache. Loading libraries
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from the web also prevents us from developing our application offline or where connectivity is
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poor. Let's learn to download the libraries to our machine and serve them locally.
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* We want our development cycle to be as fast and friction-free as possible.
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When we change our code, we want to see the results in the browser immediately.
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We have tools and procedures for that.
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3. We add the `<my-app>` tag in the `<body>`. **This is where our app lives!**
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Something has to find and load our application modules. We're using **SystemJS** to do that.
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There are other choices and we're not saying SystemJS is the best. We like it and it works.
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The specifics of SystemJS configuration are out of bounds.
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We'll briefly describe this particular configuration in the [appendix below](#systemjs).
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When Angular calls the `bootstrap` function in `boot.ts`, it reads the `AppComponent`
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metadata, finds the `my-app` selector, locates an element tag named `my-app`,
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and loads our application between those tags.
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.l-main-section
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:marked
|
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|
|
## Compile and run!
|
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Open a terminal window and enter this command:
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|
code-example(format="").
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npm run both
|
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:marked
|
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That command runs two parallel node processes
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1. The TypeScript compiler in watch mode
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1. A static server called **lite-server** that loads `index.html` in a browser
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and refreshes the browser when application files change
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In a few moments, a browser tab should open and display
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figure.image-display
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|
img(src='/resources/images/devguide/quickstart/my-first-app.png' alt="Output of quickstart app")
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:marked
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|
Congratulations! We are in business.
|
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|
.alert.is-helpful
|
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:marked
|
|
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|
|
## Upping our game
|
|
|
|
|
Let's take a few more steps to put our development on a better foundation. We will
|
|
|
|
|
If you see `Loading...` displayed instead, see the
|
|
|
|
|
[Browser ES6 support appendix](#es6support).
|
|
|
|
|
:marked
|
|
|
|
|
### Make some changes
|
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|
Try changing the message to "My SECOND Angular 2 app".
|
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|
The TypeScript compiler and `lite-server` are watching.
|
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|
They should detect the change, recompile the TypeScript into JavaScript,
|
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|
|
refresh the browser, and display the revised message.
|
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|
|
1. Revise the application project structure for future growth
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|
|
1. Install a few tools and packages
|
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|
|
1. Revise the **`index.html`** to use local library resources
|
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|
|
|
1. Compile the TypeScript locally and watch for changes
|
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|
|
Shut down the `live-server` running in the terminal window (Ctrl-C) and proceed as follows.
|
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|
|
It's a nifty way to develop an application!
|
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|
We close the terminal window when we're done to terminate both the compiler and the server.
|
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|
|
.l-main-section
|
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|
:marked
|
|
|
|
|
## Revise the application project structure
|
|
|
|
|
|
|
|
|
|
At the moment we're dumping everything into the "angular2-quickstart" **root folder**.
|
|
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|
|
Not bad when there are only two files. Not good as our application evolves.
|
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|
|
|
|
|
|
|
|
Let's give our project a little structure.
|
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|
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|
|
We'll add a sub-folder - `src` - to hold project source code and a sub-sub-folder - `src/app` -
|
|
|
|
|
to hold the application source code.
|
|
|
|
|
|
|
|
|
|
In OS/X and Linux:
|
|
|
|
|
|
|
|
|
|
pre.prettyprint.lang-bash
|
|
|
|
|
code mkdir -p src/app
|
|
|
|
|
|
|
|
|
|
:marked
|
|
|
|
|
In Windows:
|
|
|
|
|
|
|
|
|
|
pre.prettyprint.lang-bash
|
|
|
|
|
code mkdir src\app
|
|
|
|
|
|
|
|
|
|
:marked
|
|
|
|
|
**Move `index.html`** into the **`src`** folder.
|
|
|
|
|
|
|
|
|
|
**Move `app.ts`** into the **`src/app`** folder.
|
|
|
|
|
|
|
|
|
|
Our project folders should look like this.
|
|
|
|
|
```
|
|
|
|
|
angular2-quickstart
|
|
|
|
|
└── src
|
|
|
|
|
├── app
|
|
|
|
|
│ └── app.ts
|
|
|
|
|
└── index.html
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
.l-main-section
|
|
|
|
|
:marked
|
|
|
|
|
## Install npm packages locally
|
|
|
|
|
|
|
|
|
|
We'll replace the web-based scripts in our `index.html` with
|
|
|
|
|
scripts resident on our local machine.
|
|
|
|
|
We get those scripts by installing two runtime `npm` packages into our project.
|
|
|
|
|
|
|
|
|
|
>**angular2** - the Angular 2 library.
|
|
|
|
|
|
|
|
|
|
>**systemjs** - an open-source library that provides module loading.
|
|
|
|
|
|
|
|
|
|
We'll also install two development tools:
|
|
|
|
|
|
|
|
|
|
>**typescript** - the TypeScript compiler
|
|
|
|
|
|
|
|
|
|
>**[live-server](https://www.npmjs.com/package/live-server "Live-server")** - the static file server that reloads the browser when files change.
|
|
|
|
|
We may have loaded it earlier. We're doing it again
|
|
|
|
|
locally in our project so we are no longer vulnerable to
|
|
|
|
|
a global uninstall or version change.
|
|
|
|
|
|
|
|
|
|
**Open** a terminal window at our application's **root folder**
|
|
|
|
|
|
|
|
|
|
Enter these commands:
|
|
|
|
|
```
|
|
|
|
|
npm init -y
|
|
|
|
|
npm i angular2@2.0.0-alpha.44 systemjs@0.19.2 --save --save-exact
|
|
|
|
|
npm i typescript live-server --save-dev
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
These commands both *install* the packages and *create* an npm `package.json` that will
|
|
|
|
|
help us develop and maintain our application in the future.
|
|
|
|
|
The essence of our `package.json` should look like this:
|
|
|
|
|
|
|
|
|
|
+makeJson('quickstart/ts/package.json', { paths: 'name, version, dependencies, devDependencies'})
|
|
|
|
|
|
|
|
|
|
:marked
|
|
|
|
|
There is also a `scripts` section. **Find and replace** it with the following:
|
|
|
|
|
|
|
|
|
|
+makeJson('quickstart/ts/package.json', { paths: 'scripts'})
|
|
|
|
|
|
|
|
|
|
:marked
|
|
|
|
|
We've just extended our project world with script commands
|
|
|
|
|
that we'll be running very soon.
|
|
|
|
|
|
|
|
|
|
.l-main-section
|
|
|
|
|
:marked
|
|
|
|
|
## Update `index.html`
|
|
|
|
|
|
|
|
|
|
**Replace** the library scripts section with references to
|
|
|
|
|
scripts in the packages we just installed.
|
|
|
|
|
|
|
|
|
|
+makeExample('quickstart/ts/src/index.html', 'libraries')
|
|
|
|
|
|
|
|
|
|
:marked
|
|
|
|
|
**Update** the `System` configuration script as follows.
|
|
|
|
|
|
|
|
|
|
+makeExample('quickstart/ts/src/index.html', 'systemjs')
|
|
|
|
|
|
|
|
|
|
.l-sub-section
|
|
|
|
|
:marked
|
|
|
|
|
We won't be transpiling TypeScript in the browser anymore.
|
|
|
|
|
We'll do that on our machine and ship the generated JavaScript
|
|
|
|
|
files to the server.
|
|
|
|
|
|
|
|
|
|
We have to re-configure `system.js` to expect JavaScript files
|
|
|
|
|
with a `.js` extension by default.
|
|
|
|
|
Someday we might add a `Foo` class to our application in a `foo.ts`
|
|
|
|
|
file and import it like this
|
|
|
|
|
|
|
|
|
|
pre.prettyprint.lang-bash
|
|
|
|
|
code import {Foo} from './app/foo'
|
|
|
|
|
:marked
|
|
|
|
|
`system.js`will know to look for a file named `foo.js` in the `src/app` folder.
|
|
|
|
|
|
|
|
|
|
That's exactly what we're doing in the last line. We're
|
|
|
|
|
importing our main application file `app` (the generated `app.js` to be precise)
|
|
|
|
|
from the `src/app/` folder (we moved it there, remember?)
|
|
|
|
|
:marked
|
|
|
|
|
Here's the final version
|
|
|
|
|
|
|
|
|
|
+makeExample('quickstart/ts/src/index.html', null, 'index.html')
|
|
|
|
|
|
|
|
|
|
.l-main-section
|
|
|
|
|
:marked
|
|
|
|
|
## Prepare for TypeScript Compilation
|
|
|
|
|
|
|
|
|
|
### Add the TypeScript configuration file
|
|
|
|
|
|
|
|
|
|
We'll add a configuration file named **`tsconfig.json`**
|
|
|
|
|
to tell the editor how to interpret our TypeScript code and
|
|
|
|
|
to simplify the TypeScript compilation command that we'll run very soon.
|
|
|
|
|
|
|
|
|
|
**Change to the `src` folder and create a `tsconfig.json`** file with the following content:
|
|
|
|
|
+makeJson('quickstart/ts/src/tsconfig.json', null, 'tsconfig.json')
|
|
|
|
|
|
|
|
|
|
.alert.is-helpful
|
|
|
|
|
:marked
|
|
|
|
|
See the [TypeScript configuration appendix](#tsconfig) to learn more about
|
|
|
|
|
this file and these settings.
|
|
|
|
|
|
|
|
|
|
.l-main-section
|
|
|
|
|
:marked
|
|
|
|
|
## Final structure
|
|
|
|
|
Our final project folder structure should look like this:
|
|
|
|
|
```
|
|
|
|
|
angular2-quickstart
|
|
|
|
|
:marked
|
|
|
|
|
## Final structure
|
|
|
|
|
Our final project folder structure looks like this:
|
|
|
|
|
code-example(format="").
|
|
|
|
|
angular2-quickstart
|
|
|
|
|
├── node_modules
|
|
|
|
|
├── src
|
|
|
|
|
│ ├── app
|
|
|
|
|
| │ └── app.ts
|
|
|
|
|
│ ├── index.html
|
|
|
|
|
│ └── tsconfig.json
|
|
|
|
|
└── package.json
|
|
|
|
|
```
|
|
|
|
|
├── app
|
|
|
|
|
│ ├── app.component.ts
|
|
|
|
|
| └── boot.ts
|
|
|
|
|
├── index.html
|
|
|
|
|
├── package.json
|
|
|
|
|
└── tsconfig.json
|
|
|
|
|
:marked
|
|
|
|
|
And here are the files:
|
|
|
|
|
+makeTabs(`
|
|
|
|
|
quickstart/ts/app/app.component.ts,
|
|
|
|
|
quickstart/ts/app/boot.ts,
|
|
|
|
|
quickstart/ts/index.html,
|
|
|
|
|
quickstart/ts/package.1.json,
|
|
|
|
|
quickstart/ts/tsconfig.json
|
|
|
|
|
`,null,
|
|
|
|
|
`app/app.component.ts, app/boot.ts, index.html,package.json, tsconfig.json`)
|
|
|
|
|
:marked
|
|
|
|
|
|
|
|
|
|
.l-main-section
|
|
|
|
|
:marked
|
|
|
|
|
## Compile the TypeScript to JavaScript
|
|
|
|
|
:marked
|
|
|
|
|
## Wrap Up
|
|
|
|
|
Our first application doesn't do much. It's basically "Hello, World" for Angular 2.
|
|
|
|
|
|
|
|
|
|
We no longer transpile TypeScript to JavaScript in the browser.
|
|
|
|
|
We run the **T**ype**S**cript **C**ompiler (TSC) on our machine instead.
|
|
|
|
|
We kept it simple in our first pass: we wrote a little Angular component,
|
|
|
|
|
we added some JavaScript libraries to `index.html`, and launched with a
|
|
|
|
|
static file server. That's about all we'd expect to do for a "Hello, World" app.
|
|
|
|
|
|
|
|
|
|
Open a terminal window in the **root of the application folder** and enter:
|
|
|
|
|
**We have greater ambitions.**
|
|
|
|
|
|
|
|
|
|
pre.prettyprint.lang-bash
|
|
|
|
|
code npm run tsc
|
|
|
|
|
The good news is that the overhead of setup is (mostly) behind us.
|
|
|
|
|
We'll probably only touch the `package.json` to update libraries.
|
|
|
|
|
We'll likely open `index.html` only if we need to add a library or some css stylesheets.
|
|
|
|
|
|
|
|
|
|
:marked
|
|
|
|
|
When it's done we should find the generated *app.js* file in the *src* folder and also an *app.map.js* file that
|
|
|
|
|
helps debuggers navigate between the JavaScript and the TypeScript source.
|
|
|
|
|
We're about to take the next step and build a small application that
|
|
|
|
|
demonstrates the great things we can build with Angular 2.
|
|
|
|
|
|
|
|
|
|
Our script set the compiler watch option (`-w`) so the
|
|
|
|
|
compiler stays alive when it's finished.
|
|
|
|
|
It watches for changes to our **`.ts`** files
|
|
|
|
|
and recompiles them automatically.
|
|
|
|
|
Join us on the [Tour of Heroes Tutorial](./tutorial)!
|
|
|
|
|
|
|
|
|
|
Leave this command running in the terminal window.
|
|
|
|
|
You can stop it anytime with `Ctrl-C`.
|
|
|
|
|
|
|
|
|
|
.l-main-section
|
|
|
|
|
:marked
|
|
|
|
|
## Run the app!
|
|
|
|
|
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Now we are ready to see our app in action.
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Open another terminal window in the **root of the application folder** and
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launch `live-server` again although this time we'll do it with
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one of our `npm` script commands:
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pre.prettyprint.lang-bash
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code npm start
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:marked
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**live-server** loads the browser for us, serves the HTML and JavaScript files,
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and displays our application message once more:
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figure.image-display
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img(src='/resources/images/devguide/quickstart/my-first-app.png' alt="Output of quickstart app")
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:marked
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### Make some changes
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**`live-server`** detects changes to our files and refreshes the browser page for us automatically.
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Try changing the message to "My SECOND Angular 2 app".
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The TypeScript compiler in the first terminal window is watching our source code. It recompiles and produces
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the revised *app.js*. The `live-server` sees that change and reloads the browser.
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Keep `live-server` running in this terminal window. You can stop it anytime with `Ctrl-C`.
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:marked
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## Appendices
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The balance of this chapter is a set of appendices that
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elaborate some of the points we covered quickly above.
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There is no essential material here. Continued reading is for the curious.
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.l-main-section
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:marked
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<a id="package-json"></a>
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|
### Appendix: package.json
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[npm](https://docs.npmjs.com/) is a popular package manager and Angular application developers rely on it
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to acquire and manage the libraries their apps require.
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We specify the packages we need in an npm [package.json](https://docs.npmjs.com/files/package.json) file.
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The Angular team suggests the packages listed in the `dependencies` and `devDependencies`
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sections listed in this file:
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|
+makeJson('quickstart/ts/package.1.json',{ paths: 'dependencies, devDependencies'}, 'package.json (dependencies)')(format=".")
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:marked
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|
.l-sub-section
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:marked
|
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|
|
## What have we done?
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|
Our first application doesn't do much. It's basically "Hello, World" for Angular 2.
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We kept it simple in our first pass: we wrote a little Angular component,
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|
we added some JavaScript libraries to `index.html`, and launched with a
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|
static file server. That's about all we'd expect to do for a "Hello, World" app.
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|
**We have greater ambitions.**
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|
We won't ask Angular to build "Hello, World".
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|
We are asking it to help us build sophisticated applications with sophisticated requirements.
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|
So we made some strategic technology investments to reach our larger goals
|
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|
* our application loads faster with libraries installed locally and
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|
we can develop offline if we wish.
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|
* we're pre-compiling our TypeScript.
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|
* we're running the compiler and live-server with commands that give us immediate feedback as we make changes.
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|
The good news is that the overhead of setup is (mostly) behind us.
|
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|
|
We're about to build a small application that demonstrates the great things
|
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|
|
we can build with Angular 2.
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|
|
<!--TODO: Join us on the [Tour of Heroes](./toh-pt1.html) -->
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|
There are other possible package choices.
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|
We're recommending this particular set that we know work well together.
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|
|
Play along with us for now.
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|
Feel free to make substitutions later to suit your tastes and experience.
|
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|
|
:marked
|
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|
|
A `package.json` has an optional **scripts** section where we can define helpful
|
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|
|
commands to perform development and build tasks.
|
|
|
|
|
We've included a number of such scripts in our suggested `package.json`:
|
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|
|
+makeJson('quickstart/ts/package.1.json',{ paths: 'scripts'}, 'package.json (scripts)')(format=".")
|
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|
|
:marked
|
|
|
|
|
We've seen how we can run the compiler and a server at the same time with this command:
|
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|
|
code-example(format="").
|
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|
|
npm run both
|
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|
|
:marked
|
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|
|
We execute npm scripts in that manner: `npm run` + *script-name*. Here's what these scripts do:
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|
* `npm run tsc` - run the TypeScript compiler once
|
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|
|
* `npm run tsc:w` - run the TypeScript compiler in watch mode;
|
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|
|
the process keeps running, awaiting changes to TypeScript files and re-compiling when it sees them.
|
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|
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|
|
* `npm run lite` - run the [lite-server](https://www.npmjs.com/package/lite-server),
|
|
|
|
|
a light-weight, static file server, written and maintained by [John Papa](http://johnpapa.net/)
|
|
|
|
|
with excellent support for Angular apps that use routing.
|
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|
|
|
|
|
|
|
|
<!-- Move this to the Style Guide when we have one -->
|
|
|
|
|
.l-main-section
|
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|
|
|
:marked
|
|
|
|
|
<a id="tsconfig"></a>
|
|
|
|
|
### Appendix: TypeScript configuration
|
|
|
|
|
We added a TypeScript configuration file (`tsconfig.json`) to our project to
|
|
|
|
|
guide the compiler as it generates JavaScript files.
|
|
|
|
|
Get details about `tsconfig.json` from the official
|
|
|
|
|
[TypeScript wiki](https://github.com/Microsoft/TypeScript/wiki/tsconfig.json).
|
|
|
|
|
:marked
|
|
|
|
|
<a id="tsconfig"></a>
|
|
|
|
|
### Appendix: TypeScript configuration
|
|
|
|
|
We added a TypeScript configuration file (`tsconfig.json`) to our project to
|
|
|
|
|
guide the compiler as it generates JavaScript files.
|
|
|
|
|
Get details about `tsconfig.json` from the official
|
|
|
|
|
[TypeScript wiki](https://github.com/Microsoft/TypeScript/wiki/tsconfig.json).
|
|
|
|
|
|
|
|
|
|
We'd like a moment to discuss the `noImplicitAny` flag.
|
|
|
|
|
TypeScript developers disagree about whether it should be `true` or `false`.
|
|
|
|
|
There is no correct answer and we can change the flag later.
|
|
|
|
|
But our choice now can make a difference in larger projects so it merits
|
|
|
|
|
discussion.
|
|
|
|
|
The options and flags in the file we provided are essential.
|
|
|
|
|
|
|
|
|
|
We'd like a moment to discuss the `noImplicitAny` flag.
|
|
|
|
|
TypeScript developers disagree about whether it should be `true` or `false`.
|
|
|
|
|
There is no correct answer and we can change the flag later.
|
|
|
|
|
But our choice now can make a difference in larger projects so it merits
|
|
|
|
|
discussion.
|
|
|
|
|
|
|
|
|
|
When the `noImplicitAny` flag is `false`,
|
|
|
|
|
the compiler silently defaults the type of a variable to `any` if it cannot infer
|
|
|
|
|
the type based on how the variable is used. That's what we mean by "implicitly `any`".
|
|
|
|
|
When the `noImplicitAny` flag is `false`,
|
|
|
|
|
the compiler silently defaults the type of a variable to `any` if it cannot infer
|
|
|
|
|
the type based on how the variable is used. That's what we mean by "implicitly `any`".
|
|
|
|
|
|
|
|
|
|
When the `noImplicitAny` flag is `true` and the TypeScript compiler cannot infer
|
|
|
|
|
the type, it still generates the JavaScript files but
|
|
|
|
|
it also reports an error.
|
|
|
|
|
When the `noImplicitAny` flag is `true` and the TypeScript compiler cannot infer
|
|
|
|
|
the type, it still generates the JavaScript files but
|
|
|
|
|
it also reports an error.
|
|
|
|
|
|
|
|
|
|
For this project and the other examples in this Developer Guide
|
|
|
|
|
we set the `noImplicitAny` flag to `false`.
|
|
|
|
|
Developers who prefer stricter type checking should set the `noImplicitAny` flag to `true`.
|
|
|
|
|
We can still set a variable's type to `any` if
|
|
|
|
|
that seems like the best choice. We'd be doing so explicitly after
|
|
|
|
|
giving the matter some thought.
|
|
|
|
|
In this QuickStart and many of the other samples in this Developer Guide
|
|
|
|
|
we set the `noImplicitAny` flag to `false`.
|
|
|
|
|
|
|
|
|
|
Developers who prefer stricter type checking should set the `noImplicitAny` flag to `true`.
|
|
|
|
|
We can still set a variable's type to `any` if
|
|
|
|
|
that seems like the best choice. We'd be doing so explicitly after
|
|
|
|
|
giving the matter some thought.
|
|
|
|
|
|
|
|
|
|
If we set the `noImplicitAny` flag to `true`, we may get implicit index errors as well.
|
|
|
|
|
If we feel these are more annoying than helpful,
|
|
|
|
|
we can suppress them with the following additional flag.
|
|
|
|
|
```
|
|
|
|
|
"suppressImplicitAnyIndexErrors":true
|
|
|
|
|
```
|
|
|
|
|
If we set the `noImplicitAny` flag to `true`, we may get implicit index errors as well.
|
|
|
|
|
If we feel these are more annoying than helpful,
|
|
|
|
|
we can suppress them with the following additional flag.
|
|
|
|
|
```
|
|
|
|
|
"suppressImplicitAnyIndexErrors":true
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
.l-main-section
|
|
|
|
|
:marked
|
|
|
|
|
<a id="systemjs"></a>
|
|
|
|
|
### Appendix: SystemJS Configuration
|
|
|
|
|
|
|
|
|
|
The QuickStart uses [SystemJS](https://github.com/systemjs/systemjs) to load application
|
|
|
|
|
and library modules.
|
|
|
|
|
There are alternatives that work just fine including the well-regarded [webpack](https://webpack.github.io/).
|
|
|
|
|
SystemJS happens to be a good choice but we want to be clear that it was a choice and not a preference.
|
|
|
|
|
|
|
|
|
|
All module loaders require configuration and all loader configuration
|
|
|
|
|
becomes complicated rather quickly as soon as the file structure diversifies and
|
|
|
|
|
we start thinking about building for production and performance.
|
|
|
|
|
|
|
|
|
|
We suggest becoming well-versed in the loader of your choice.
|
|
|
|
|
.l-sub-section
|
|
|
|
|
:marked
|
|
|
|
|
<a id="es6support"></a>
|
|
|
|
|
### Appendix: Browser ES6 support
|
|
|
|
|
Angular 2 requires ES6 support, such as can be found in most modern
|
|
|
|
|
browsers. For older browsers (including IE 11) you can use a shim to get
|
|
|
|
|
the needed functionality.
|
|
|
|
|
|
|
|
|
|
After creating `package.json` (halfway through the quickguide), run this
|
|
|
|
|
command to add a shim to the project:
|
|
|
|
|
|
|
|
|
|
code-example(language="sh" format=".").
|
|
|
|
|
npm install es6-shim --save
|
|
|
|
|
|
|
|
|
|
Learn more about SystemJS configuration [here](https://github.com/systemjs/systemjs/blob/master/docs/config-api.md).
|
|
|
|
|
:marked
|
|
|
|
|
With those caustions in mind, what are we doing here?
|
|
|
|
|
+makeExample('quickstart/ts/index.html', 'systemjs', 'index.html (System configuration')(format=".")
|
|
|
|
|
:marked
|
|
|
|
|
The `packages:` line tells SystemJS what to do when it sees a request for a
|
|
|
|
|
module from the `app/` folder.
|
|
|
|
|
|
|
|
|
|
Our QuickStart makes such requests when one of its
|
|
|
|
|
application TypeScript files has an import statement like this:
|
|
|
|
|
+makeExample('quickstart/ts/app/boot.ts', 'app-component', 'boot.ts (excerpt)')(format=".")
|
|
|
|
|
:marked
|
|
|
|
|
Notice that the module name (after `from`) does not mention a filename extension.
|
|
|
|
|
The `packages:` configuration tells SystemJS to default the extension to 'js', a JavaScript file.
|
|
|
|
|
|
|
|
|
|
That makes sense because we transpile TypeScript to JavaScript
|
|
|
|
|
*before* running the application.
|
|
|
|
|
|
|
|
|
|
.l-sub-section
|
|
|
|
|
:marked
|
|
|
|
|
Now you can load the shim in your `index.html` before the other scripts:
|
|
|
|
|
|
|
|
|
|
code-example(language="html" format=".").
|
|
|
|
|
<script src="../node_modules/es6-shim/es6-shim.js"></script>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
In the live example on plunker we transpile (AKA compile) to JavaScript in the browser
|
|
|
|
|
on the fly. That's fine for a demo. That's not our preference for development or production.
|
|
|
|
|
|
|
|
|
|
We recommend transpiling (AKA compiling) to JavaScript during a build phase
|
|
|
|
|
before running the application for several reasons including:
|
|
|
|
|
|
|
|
|
|
* We see compiler warnings and errors that are hidden from us in the browser.
|
|
|
|
|
|
|
|
|
|
* Pre-compilation simpifies the module loading process and
|
|
|
|
|
it's much easier to diagnose problem when this is a separate, external step.
|
|
|
|
|
|
|
|
|
|
* Pre-compilation means a faster user experience because the browser doesn't waste time compiling.
|
|
|
|
|
|
|
|
|
|
* We iterate development faster because we only re-compile changed files.
|
|
|
|
|
We notice the difference as soon as the app grows beyond a handful of files.
|
|
|
|
|
|
|
|
|
|
* pre-compilation fits into a continuous integration process of build, test, deploy.
|
|
|
|
|
:marked
|
|
|
|
|
The `System.Import` call tells SystemJS to import the `boot` file
|
|
|
|
|
(`boot.js` ... after transpiling `boot.ts`, remember?).
|
|
|
|
|
`boot` is where we tell Angular to launch the application.
|
|
|
|
|
|
|
|
|
|
All other modules are loaded upon request
|
|
|
|
|
either by an import statement or by Angular itself.
|
|
|
|
|
|
|
|
|
|
.l-main-section
|
|
|
|
|
:marked
|
|
|
|
|
<a id="es6support"></a>
|
|
|
|
|
### Appendix: Browser ES6 support
|
|
|
|
|
Angular 2 relies on some ES2015 features, most of them found in modern
|
|
|
|
|
browsers. Some browsers (including IE 11) require a shim to support the
|
|
|
|
|
the needed functionality.
|
|
|
|
|
Try loading the following shim *above* the other scripts in the `index.html`:
|
|
|
|
|
|
|
|
|
|
code-example(language="html" format=".").
|
|
|
|
|
<script src="node_modules/es6-shim/es6-shim.js"></script>
|
|
|
|
|
|
Ward Bell