docs(pipes): sample shuffle, refactor, alpha.53

closes #487

public/docs/_examples/pipes/ts/app/app.component.html

@@ -1,12 +1,11 @@
+<hr>
 <!-- async examples at the top so can see them in action -->
-<my-hero></my-hero>
+<hero-message></hero-message>
 
 <hr>
-
 <hero-list></hero-list>
 
 <hr>
-
 <!-- #docregion hero-birthday-template -->
 <p>The hero's birthday is {{ birthday | date }}</p>
 <!-- #enddocregion hero-birthday-template-->
@@ -16,8 +15,7 @@
 <!-- #enddocregion format-birthday-->
 
 <hr>
-
-<h4>Hero Birthday 2</h4>
+<h4>Hero Birthday v.2</h4>
 <hero-birthday>loading...</hero-birthday>
 <hr>
 
@@ -32,15 +30,18 @@
 <!-- #docregion chained-parameter-birthday -->
 <p>
   The chained hero's birthday is
-  {{ ( birthday | date:'fullDate' ) | uppercase}}
+  {{  birthday | date:'fullDate' | uppercase}}
 </p>
 <!-- #enddocregion chained-parameter-birthday -->
-
+<!-- #docregion chained-parameter-birthday-parens -->
+<p>
+  The chained hero's birthday is
+  {{ ( birthday | date:'fullDate' ) | uppercase}}
+</p>
+<!-- #enddocregion chained-parameter-birthday-parens -->
 <hr>
-
 <power-booster>loading...</power-booster>
 
 <hr>
-
 <power-boost-calculator>loading ..</power-boost-calculator>
 

public/docs/_examples/pipes/ts/app/app.component.ts

@@ -0,0 +1,21 @@
+// #docregion
+import {Component} from 'angular2/core';
+import {HeroAsyncMessageComponent} from './hero-async-message.component';
+import {HeroBirthday} from './hero-birthday2.component';
+import {HeroListComponent} from './hero-list.component';
+import {PowerBooster} from './power-booster.component';
+import {PowerBoostCalculator} from './power-boost-calculator.component';
+
+@Component({
+  selector: 'my-app',
+  templateUrl: 'app/app.component.html',
+  directives:[
+    HeroAsyncMessageComponent,
+    HeroBirthday,
+    HeroListComponent,
+    PowerBooster, PowerBoostCalculator
+  ]
+})
+export class AppComponent {
+  birthday = new Date(1988,3,15); // April 15, 1988
+}

public/docs/_examples/pipes/ts/app/boot.ts

@@ -0,0 +1,6 @@
+import {bootstrap}    from 'angular2/platform/browser';
+import {AppComponent} from './app.component';
+import {HeroBirthday} from './hero-birthday1.component';
+
+bootstrap(AppComponent);
+bootstrap(HeroBirthday); // v.1

public/docs/_examples/pipes/ts/app/exponential-strength.pipe.ts

@@ -1,5 +1,5 @@
 // #docregion
-import {Pipe} from 'angular2/angular2';
+import {Pipe} from 'angular2/core';
 /*
  * Raise the value exponentially
  * Takes an exponent argument that defaults to 1.
@@ -9,13 +9,10 @@ import {Pipe} from 'angular2/angular2';
  *   {{ 2 |  exponentialStrength:10}}
  *   formats to: 1024
 */
-@Pipe({
-  name: 'exponentialStrength'
-})
+@Pipe({name: 'exponentialStrength'})
 export class ExponentialStrengthPipe {
 
   transform(value:number, args:string[]) : any {
     return Math.pow(value, parseInt(args[0] || '1', 10));
   }
 }
-// #enddocregion

public/docs/_examples/pipes/ts/app/fetch-json.pipe.ts

@@ -1,7 +1,6 @@
-///<reference path="./window.extension.d.ts"/>
-
+/// <reference path='./window.extension.d.ts'/>
 // #docregion
-import {Pipe} from 'angular2/angular2';
+import {Pipe} from 'angular2/core';
 
 // #docregion pipe-metadata
 @Pipe({
@@ -12,13 +11,12 @@ import {Pipe} from 'angular2/angular2';
 export class FetchJsonPipe {
   private fetchedValue:any;
   private fetchPromise:Promise<any>;
+
   transform(value:string, args:string[]):any {
     if (!this.fetchPromise) {
       this.fetchPromise = window.fetch(value)
-        .then(result => result.json())
-        .then(json => {
-          this.fetchedValue = json;
-        });
+        .then((result:any) => result.json())
+        .then((json:any)   => this.fetchedValue = json);
     }
 
     return this.fetchedValue;

public/docs/_examples/pipes/ts/app/hero-async-message.component.ts

@@ -0,0 +1,15 @@
+// #docregion
+import {Component} from 'angular2/core';
+
+// Initial view: "Message: "
+// After 500ms: Message: You are my Hero!"
+
+@Component({
+  selector: 'hero-message',
+  template: 'Message: {{delayedMessage | async}}',
+})
+export class HeroAsyncMessageComponent {
+  delayedMessage:Promise<string> = new Promise((resolve, reject) => {
+    setTimeout(() => resolve('You are my Hero!'), 500);
+  });
+}

public/docs/_examples/pipes/ts/app/hero-birthday1.component.ts

@@ -0,0 +1,14 @@
+// Version #1
+// #docregion
+import {Component} from 'angular2/core'
+
+@Component({
+  selector: 'hero-birthday',
+  // #docregion hero-birthday-template
+  template: `<p>The hero's birthday is {{ birthday | date }}</p>`
+  // #enddocregion hero-birthday-template
+})
+export class HeroBirthday {
+  birthday = new Date(1988,3,15); // April 15, 1988
+}
+// #enddocregion

public/docs/_examples/pipes/ts/app/hero-birthday2.component.ts

@@ -1,16 +1,24 @@
-import {bootstrap, Component} from 'angular2/angular2'
+// Version #2
 // #docregion
+import {Component} from 'angular2/core'
+
 @Component({
   selector: 'hero-birthday',
+// #docregion template
   template: `
     <p>The hero's birthday is {{ birthday | date:format }}</p>
     <button (click)="toggleFormat()">Toggle Format</button>
   `
+// #enddocregion template
 })
+// #docregion class
 export class HeroBirthday {
   birthday = new Date(1988,3,15); // April 15, 1988
+
+  toggle = true; // start with true == shortDate
+
   get format() { return this.toggle ? 'shortDate' : 'fullDate'}
-  toggle = true;
+
   toggleFormat() { this.toggle = !this.toggle; }
 }
-// #enddocregion
+// #enddocregion class

public/docs/_examples/pipes/ts/app/hero-list.component.ts

@@ -0,0 +1,24 @@
+// #docregion
+import {Component} from 'angular2/core';
+import {FetchJsonPipe} from './fetch-json.pipe';
+
+@Component({
+  selector: 'hero-list',
+  // #docregion template
+  template: `
+    <h4>Heroes from JSON File</h4>
+
+    <div *ngFor="#hero of ('heroes.json' | fetch) ">
+      {{hero.name}}
+    </div>
+
+    <p>Heroes as JSON:
+    {{'heroes.json' | fetch | json}}
+    </p>
+  `,
+  // #enddocregion template
+  pipes: [FetchJsonPipe]
+})
+export class HeroListComponent {
+  /* I've got nothing to do ;-) */
+}

public/docs/_examples/pipes/ts/app/power-boost-calculator.component.ts

@@ -0,0 +1,20 @@
+// #docregion
+import {Component} from 'angular2/core';
+import {ExponentialStrengthPipe} from './exponential-strength.pipe';
+
+@Component({
+  selector: 'power-boost-calculator',
+  template: `
+    <h2>Power Boost Calculator</h2>
+    <div>Normal power: <input [(ngModel)]="power"></div>
+    <div>Boost factor: <input [(ngModel)]="factor"></div>
+    <p>
+      Super Hero Power: {{power | exponentialStrength: factor}}
+    </p>
+  `,
+  pipes: [ExponentialStrengthPipe]
+})
+export class PowerBoostCalculator {
+  power = 5;
+  factor = 1;
+}

public/docs/_examples/pipes/ts/app/power-booster.component.ts

@@ -1,6 +1,6 @@
 // #docregion
-import {Component} from 'angular2/angular2'
-import {ExponentialStrengthPipe} from './exponential-strength-pipe'
+import {Component} from 'angular2/core';
+import {ExponentialStrengthPipe} from './exponential-strength.pipe';
 
 @Component({
   selector: 'power-booster',

public/docs/_examples/pipes/ts/app/window.extension.d.ts

@@ -0,0 +1,3 @@
+interface Window {
+  fetch(url: string, options? : {}) : Promise<any>
+}

public/docs/_examples/pipes/ts/index.html

@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<html>
+
+  <head>
+    <title>Pipes</title>
+    <script src="node_modules/systemjs/dist/system.src.js"></script>
+    <script src="node_modules/angular2/bundles/angular2.dev.js"></script>
+    <script>
+      System.config({
+        packages: {'app': {defaultExtension: 'js'}}
+      });
+      System.import('app/boot');
+    </script>
+  </head>
+
+  <body>
+    <h4>Hero Birthday v.1</h4>
+    <hero-birthday>hero-birthday loading...</hero-birthday>
+
+    <my-app>my-app loading ...</my-app>
+  </body>
+
+</html>

public/docs/_examples/pipes/ts/plnkr.json

@@ -0,0 +1,8 @@
+{
+  "description": "Pipes",
+  "files":[
+    "!**/*.d.ts",
+    "!**/*.js",
+    "!**/*.d.ts"],
+  "tags": ["pipe"]
+}

public/docs/_examples/pipes/ts/src/app/app.ts

@@ -1,52 +0,0 @@
-import {HeroBirthday as HeroBirthday2} from './hero-birthday';
-import {PowerBooster} from './power-booster';
-import {PowerBoostCalculator} from './power-boost-calculator';
-import {HeroListComponent} from './hero-list-component';
-
-// #docregion hero-birthday
-import {bootstrap, Component} from 'angular2/angular2'
-
-@Component({ 
-  selector: 'hero-birthday',
-  // #docregion hero-birthday-template
-  template: `<p>The hero's birthday is {{ birthday | date }}</p>`
-  // #enddocregion hero-birthday-template  
-})
-export class HeroBirthday {
-  birthday = new Date(1988,3,15); // April 15, 1988
-}
-
-bootstrap(HeroBirthday);
-// #enddocregion hero-birthday
-
-// #docregion async-message
-@Component({
-  selector: 'my-hero',
-  template: 'Message: {{delayedMessage | async}}',
-})
-class MyHeroAsyncMessageComponent {
-  delayedMessage:Promise<string> = new Promise((resolve, reject) => {
-    setTimeout(() => resolve('You are my Hero!'), 500);
-  });
-}
-
-// Initial view: "Message: "
-// After 500ms: Message: You are my Hero!"
-// #enddocregion async-message
-
-//// Drives the rest of the pipes chapter examples ///
-
-@Component({ 
-  selector: 'my-app',
-  templateUrl: 'app/app.html',
-  directives:[
-    HeroBirthday2, 
-    PowerBooster, PowerBoostCalculator,
-    MyHeroAsyncMessageComponent,
-    HeroListComponent]
-})
-class AppComponent {
-  birthday = new Date(1988,3,15); // April 15, 1988
-}
-bootstrap(AppComponent);
-  

public/docs/_examples/pipes/ts/src/app/hero-list-component.ts

@@ -1,25 +0,0 @@
-// #docregion
-import {bootstrap, Component, 
-        CORE_DIRECTIVES, FORM_DIRECTIVES} from 'angular2/angular2'
-
-import {FetchJsonPipe} from './fetch-json-pipe'
-
-@Component({
-  selector: 'hero-list',
-  template: `
-    <h4>Heroes from JSON File</h4>
-    
-    <div *ng-for="#hero of ('heroes.json' | fetch) ">
-      {{hero.name}}
-    </div>
-    
-    <p>Heroes as JSON: 
-    {{'heroes.json' | fetch | json}}
-    </p>
-  `,
-  directives:[CORE_DIRECTIVES],
-  pipes: [FetchJsonPipe]
-})
-export class HeroListComponent { 
-  /* I've got nothing to do ;-) */ 
-}

public/docs/_examples/pipes/ts/src/app/power-boost-calculator.ts

@@ -1,21 +0,0 @@
-// #docregion
-import {Component, FORM_DIRECTIVES} from 'angular2/angular2'
-import {ExponentialStrengthPipe} from './exponential-strength-pipe'
-
-@Component({ 
-  selector: 'power-boost-calculator',
-  template: `
-    <h2>Power Boost Calculator</h2>
-    <div>Normal power: <input [(ng-model)]="power"></div>
-    <div>Boost factor: <input [(ng-model)]="factor"></div>
-    <p>
-      Super Hero Power: {{power | exponentialStrength: factor}}
-    </p>
-  `,
-  pipes: [ExponentialStrengthPipe],
-  directives: [FORM_DIRECTIVES]
-})
-export class PowerBoostCalculator { 
-  power = 5;
-  factor = 1;
-}

public/docs/_examples/pipes/ts/src/app/window.extension.d.ts

@@ -1,3 +0,0 @@
-interface Window {
-  fetch:(url: string, options?: {}) => Promise<any>
-}

public/docs/_examples/pipes/ts/src/index.html

@@ -1,23 +0,0 @@
-<!DOCTYPE html>
-<html>
-
-  <head>
-    <title>Pipes</title>
-    <script src="../node_modules/systemjs/dist/system.src.js"></script>
-    <script src="../node_modules/angular2/bundles/angular2.dev.js"></script>
-    <script>
-      System.config({
-        packages: {'app': {defaultExtension: 'js'}}
-      });
-      System.import('app/app');
-    </script>
-  </head>
-
-  <body>
-    <h4>Hero Birthday 1</h4>
-    <hero-birthday>loading...</hero-birthday>
-    <hr>
-    <my-app>loading ...</my-app>
-  </body>
-
-</html>

public/docs/_examples/pipes/ts/src/plnkr.json

@@ -1,3 +0,0 @@
-{
-  "files":["!**/*.d.ts",  "!**/*.js"]
-}

public/docs/ts/latest/guide/pipes.jade

@@ -17,7 +17,7 @@ include ../../../../_includes/_util-fns
 
   Welcome, Angular pipes, the simple display-value transformations that we can declare in our HTML!
   
-  [Live Example](/resources/live-examples/pipes/ts/src/plnkr.html)
+  [Live Example](/resources/live-examples/pipes/ts/plnkr.html).
 
 .l-main-section
 :marked
@@ -25,25 +25,16 @@ include ../../../../_includes/_util-fns
 
   A pipe takes in data as input and transforms it to a desired output.
   We'll illustrate by transforming a component's birthday property into
-  a human-friendly date.
-
-  Here's a complete mini-app with a `DatePipe`:
-  <!--
-    All date samples are in my plunker
-    http://plnkr.co/edit/RDlOma?p=preview
-  -->
-
-+makeExample('pipes/ts/src/app/app.ts', 'hero-birthday')
+  a human-friendly date:
++makeExample('pipes/ts/app/hero-birthday1.component.ts', null, 'app/hero-birthday1.component.ts')
 
 :marked
-  Focus on the component's template to see how we applied the built-in `DatePipe`
-  while binding the `birthday` property.
-+makeExample('pipes/ts/src/app/app.html', 'hero-birthday-template')(format=".")
-
+  Focus on the component's template. 
++makeExample('pipes/ts/app/app.component.html', 'hero-birthday-template')(format=".")
 :marked
-  Angular [template syntax](./template-syntax.html#pipe) includes a pipe operator ( | ) which we're
-  using to flow the birthday value on the left through to the `Date` pipe function on the right.
-  All pipes work this way.
+  Inside the interpolation expression we flow the component's `birthday` value through the
+  [pipe operator](./template-syntax.html#pipe) ( | ) to the [Date pipe](../api/common/DatePipe-class.html) 
+  function on the right. All pipes work this way.
 
 .l-main-section
 :marked
@@ -64,25 +55,26 @@ include ../../../../_includes/_util-fns
   We add parameters to a pipe by following the pipe name with a colon ( : ) and then the parameter value
   (e.g., `currency:'EUR'`). If our pipe accepts multiple parameters, we separate the values with colons (e.g. `slice:1:5`)
 
-  We'll modify our birthday example to give the date pipe a format parameter.
-  The formatted date should display as **<span style="font-family:courier">04/15/88</span>**.
+  We'll modify our birthday template to give the date pipe a format parameter.
+  After formatting the hero's April 15th birthday should display as **<span style="font-family:courier">04/15/88</span>**.
 
-+makeExample('pipes/ts/src/app/app.html', 'format-birthday')(format=".")
++makeExample('pipes/ts/app/app.component.html', 'format-birthday')(format=".")
 
 :marked
   The parameter value can be any valid
   [template expression](./template-expression.html#template-expressions)
   such as a string literal or a component property. 
+  In other words, we can control the format through a binding the same way we control the birthday value through a binding.
   
-  Let's revise our example to bind the pipe's format parameter
-  to the component's `format` property.
-+makeExample('pipes/ts/src/app/hero-birthday.ts')
-
+  Let's write a second component that *binds* the pipe's format parameter
+  to the component's `format` property. Here's the template for that component:
++makeExample('pipes/ts/app/hero-birthday2.component.ts', 'template', 'app/hero-birthday2.component.ts (template)')(format=".")
 :marked
   We also added a button to the template and bound its click event to the component's `toggleFormat` method.
   That method toggles the component's `format` property between a short form
   ('shortDate') and a longer form ('fullDate').
-
++makeExample('pipes/ts/app/hero-birthday2.component.ts', 'class', 'app/hero-birthday2.component.ts (class)')
+:marked
   As we click the button, the displayed date alternates between
   "**<span style="font-family:courier">04/15/1988</span>**" and
   "**<span style="font-family:courier">Friday, April 15, 1988</span>**".
@@ -90,6 +82,7 @@ include ../../../../_includes/_util-fns
 figure.image-display
     img(src='/resources/images/devguide/pipes/date-format-toggle-anim.gif' alt="Date Format Toggle")
 :marked
+
 .l-sub-section
   :marked
     Learn more about the `DatePipes` format options in the [API Docs](../api/core/DatePipe-class.html).
@@ -100,7 +93,7 @@ figure.image-display
   so we can display the birthday in uppercase. The following birthday displays as
   **<span style="font-family:courier">APR 15, 1988</span>**
 
-+makeExample('pipes/ts/src/app/app.html', 'chained-birthday')
++makeExample('pipes/ts/app/app.component.html', 'chained-birthday')(format=".")
 
 :marked
   If we pass a parameter to a filter, we have to add parentheses
@@ -108,10 +101,14 @@ figure.image-display
   The following example displays
   **<span style="font-family:courier">FRIDAY, APRIL 15, 1988</span>**
 
-+makeExample('pipes/ts/src/app/app.html', 'chained-parameter-birthday')
++makeExample('pipes/ts/app/app.component.html', 'chained-parameter-birthday')(format=".")
 
 .l-sub-section
-  p Future improvements in the template compiler may eliminate the need for parentheses.
+  :marked
+    We can add parentheses to alter the evaluation order or 
+    to provide extra clarity:
+  +makeExample('pipes/ts/app/app.component.html', 'chained-parameter-birthday-parens')(format=".")
+:marked
 
 .l-main-section
 :marked
@@ -119,43 +116,39 @@ figure.image-display
 
   We can write our own custom pipes.
 
-  Let's make a custom pipe named `ExponentialStrengthPipe`
-  that can boost a hero's powers.
-
-  Create a new file, `exponential-strength-pipe.ts`, and enter the following:
-  <!--
-    The exponential pipe samples are in my plunker
-    http://plnkr.co/edit/8Nnnwf?p=preview
-  -->
-+makeExample('pipes/ts/src/app/exponential-strength-pipe.ts')
+  Here's a custom pipe named `ExponentialStrengthPipe` that can boost a hero's powers:
 
++makeExample('pipes/ts/app/exponential-strength.pipe.ts', null, 'app/exponential-strength.pipe.ts')
 :marked
   This pipe definition reveals several key points
-  * We import the `Pipe` decorator from the Angular library (while getting the usual symbols)
-  * A pipe is a class
-  * We decorate the class with the `@Pipe` decorator function.
+  
+  * A pipe is a class decorated with pipe metadata.
+     
+  * The pipe class implements a `transform` method that
+  takes an input value and an optional array of parameter strings and returns the transformed value.
+
+  * There will be one item in the parameter array for each parameter passed to the pipe
+  
+  * We tell Angular that this is a pipe by applying the
+  `@Pipe` decorator which we import from the core Angular library.
+  
   * The `@Pipe` decorator takes an object with a name property whose value is the
      pipe name that we'll use within a template expression. It must be a valid JavaScript identifier.
      Our pipe's name is `exponenentialStrength`.
-  * The pipe class implements a `transform` method
-  * `transform` takes a value and an optional array of strings.
-     The value can be of any type but the arguments array must be an array of strings.
-  * There will be one item in the array for each parameter passed to the pipe
-  * `transform` returns a modified value that Angular converts to a string.
 
-  Now let's create a component to demonstrate our pipe.
-+makeExample('pipes/ts/src/app/power-booster.ts')
+
+  Now we need a component to demonstrate our pipe.
++makeExample('pipes/ts/app/power-booster.component.ts',null,'app/power-booster.component.ts')
 figure.image-display
     img(src='/resources/images/devguide/pipes/power-booster.png' alt="Power Booster")
 
 :marked
   Two things to note:
-  1. We use the pipe in the template expression exactly as we described in the pipe's comments.
-  We pass the value to transform from the left and give our pipe an exponent parameter of `10`.
+  1. We use our custom pipe the same way we use the built-in pipes.
 
   1. We must list our pipe in the @Component decorator's `pipes` array.
 
-.callout.is-critical
+.callout.is-helpful
   header Remember the pipes array!
   :marked
     Angular reports an error if we neglect to list our custom pipe.
@@ -163,18 +156,18 @@ figure.image-display
     Angular built-in pipes are pre-registered.
     Custom pipes must be registered manually.
 :marked
-  If we are inclined to try this in a live-coding tool (such a [plunker](http://plnkr.co/)),
+  If we try the [live code](/resources/live-examples/pipes/ts/plnkr.html) example,
   we can probe its behavior by changing the value and the optional exponent in the template.
 
   ## Power Boost Calculator (extra-credit)
   It's not much fun updating the template to test our custom pipe.
   We could upgrade the example to a "Power Boost Calculator" that combines
-  our pipe and two-way data binding with `ng-model`.
+  our pipe and two-way data binding with `ngModel`.
 
-+makeExample('pipes/ts/src/app/power-boost-calculator.ts')
++makeExample('pipes/ts/app/power-boost-calculator.component.ts', null, '/app/power-boost-calculator.component.ts')
 
 figure.image-display
-    img(src='/resources/images/devguide/pipes/power-boost-calculator.png' alt="Power Boost Calculator")
+    img(src='/resources/images/devguide/pipes/power-boost-calculator-anim.gif' alt="Power Boost Calculator")
 :marked
 
 .l-main-section
@@ -200,7 +193,7 @@ figure.image-display
   It is stateful because the pipe maintains a subscription to the input and its returned values depend on that subscription.
 
   In the next example, we bind a simple promise to a view with the async pipe.
-+makeExample('pipes/ts/src/app/app.ts', 'async-message')
++makeExample('pipes/ts/app/hero-async-message.component.ts', null, 'app/hero-async-message.component.ts')
 
 :marked
   The Async pipe saves boilerplate in the component code.
@@ -219,21 +212,36 @@ figure.image-display
 
   Here's how we'll decorate our new stateful `FetchJsonPipe` that
   makes an HTTP `fetch` request and (eventually) displays the data in the server's response:
-+makeExample('pipes/ts/src/app/fetch-json-pipe.ts', 'pipe-metadata')
++makeExample('pipes/ts/app/fetch-json.pipe.ts', 'pipe-metadata','app/fetch-json.pipe.ts (metadata)')
 :marked
   Immediately below we have the finished pipe. Its input value is an url to an endpoint that returns a JSON file.
   The pipe makes a one-time async request to the server and eventually receives the JSON response.
-+makeExample('pipes/ts/src/app/fetch-json-pipe.ts')
++makeExample('pipes/ts/app/fetch-json.pipe.ts', null, 'app/fetch-json.pipe.ts')
 :marked
-  Next we use this pipe in two template bindings where we
-  1. display hero names in an `ng-for` repeater
-  1. chain the fetched results to the built-in `JsonPipe` that renders
-  the data in JSON format
-
-+makeExample('pipes/ts/src/app/hero-list-component.ts')
-
+  Next we demonstrate this pipe in a test component whose template defines two bindings
++makeExample('pipes/ts/app/hero-list.component.ts', 'template', 'app/hero-list.component.ts (template)')
+:marked
+  The component renders like this:
 figure.image-display
     img(src='/resources/images/devguide/pipes/hero-list.png' alt="Hero List")
+:marked
+  The first binding is straight forward. An `ngFor` repeater displays the hero names fetched from a json source file.
+  We're piping the literal file name, "heroes.json", through to the custom `fetch` pipe.
+
+  ### JsonPipe
+  The second binding uses more pipe chaining.
+  We take the same fetched results and display the raw hero data in JSON format 
+  by piping to the built-in `JsonPipe`.
+  
+.callout.is-helpful
+  header Debugging with the json pipe
+  :marked
+    The [JsonPipe](https://angular.io/docs/ts/latest/api/common/JsonPipe-class.html) 
+    is an easy way to diagnosis a mysteriously failing data binding.
+:marked
+  Here's the complete component implementation:
++makeExample('pipes/ts/app/hero-list.component.ts', null, 'app/hero-list.component.ts')
+:marked
 
 .l-main-section
 :marked