exported from <a href='../annotations'>angular2/annotations</a>
defined in <a href="https://github.com/angular/angular/tree/2.0.0-alpha.32/modules/angular2/src/core/annotations_impl/di.ts#L3-L44">angular2/src/core/annotations_impl/di.ts (line 3)</a>
:markdown
Specifies that a constant attribute value should be injected.
The directive can inject constant string literals of host element attributes.
## Example
Suppose we have an `<input>` element and want to know its `type`.
```html
<input type="text">
```
A decorator can inject string literal `text` like so: