Component

The change-detection strategy to use for this component.

When a component is instantiated, Angular creates a change detector, which is responsible for propagating the component's bindings. The strategy is one of:

• ChangeDetectionStrategy#OnPush sets the strategy to CheckOnce (on demand).
• ChangeDetectionStrategy#Default sets the strategy to CheckAlways.

Defines the set of injectable objects that are visible to its view DOM children. See example.

The module ID of the module that contains the component. The component must be able to resolve relative URLs for templates and styles. SystemJS exposes the __moduleName variable within each module. In CommonJS, this can be set to module.id.

The relative path or absolute URL of a template file for an Angular component. If provided, do not supply an inline template using template.

An inline template for an Angular component. If provided, do not supply a template file using templateUrl.

One relative paths or an absolute URL for files containing CSS stylesheet to use in this component.

Relative paths or absolute URLs for files containing CSS stylesheets to use in this component.

One or more inline CSS stylesheets to use in this component.

One or more animation trigger() calls, containing state() and transition() definitions. See the Animations guide and animations API documentation.

An encapsulation policy for the component's styling. Possible values:

• ViewEncapsulation.Emulated: Apply modified component styles in order to emulate a native Shadow DOM CSS encapsulation behavior.
• ViewEncapsulation.None: Apply component styles globally without any sort of encapsulation.
• ViewEncapsulation.ShadowDom: Use the browser's native Shadow DOM API to encapsulate styles.

If not supplied, the value is taken from the CompilerOptions which defaults to ViewEncapsulation.Emulated.

If the policy is ViewEncapsulation.Emulated and the component has no styles nor styleUrls, the policy is automatically switched to ViewEncapsulation.None.

Overrides the default interpolation start and end delimiters ({{ and }}).

True to preserve or false to remove potentially superfluous whitespace characters from the compiled template. Whitespace characters are those matching the \s character class in JavaScript regular expressions. Default is false, unless overridden in compiler options.

Angular components marked as standalone do not need to be declared in an NgModule. Such components directly manage their own template dependencies (components, directives, and pipes used in a template) via the imports property.

More information about standalone components, directives, and pipes can be found in this guide.

The imports property specifies the standalone component's template dependencies — those directives, components, and pipes that can be used within its template. Standalone components can import other standalone components, directives, and pipes as well as existing NgModules.

This property is only available for standalone components - specifying it for components declared in an NgModule generates a compilation error.

More information about standalone components, directives, and pipes can be found in this guide.

The set of schemas that declare elements to be allowed in a standalone component. Elements and properties that are neither Angular components nor directives must be declared in a schema.

This property is only available for standalone components - specifying it for components declared in an NgModule generates a compilation error.

More information about standalone components, directives, and pipes can be found in this guide.

The CSS selector that identifies this directive in a template and triggers instantiation of the directive.

Declare as one of the following:

• element-name: Select by element name.
• .class: Select by class name.
• [attribute]: Select by attribute name.
• [attribute=value]: Select by attribute name and value.
• :not(sub_selector): Select only if the element does not match the sub_selector.
• selector1, selector2: Select if either selector1 or selector2 matches.

Angular only allows directives to apply on CSS selectors that do not cross element boundaries.

For the following template HTML, a directive with an input[type=text] selector, would be instantiated only on the <input type="text"> element.

          
<form>  <input type="text">  <input type="radio"><form>
        

Enumerates the set of data-bound input properties for a directive

Angular automatically updates input properties during change detection. The inputs property accepts either strings or object literals that configure the directive properties that should be exposed as inputs.

When an object literal is passed in, the name property indicates which property on the class the input should write to, while the alias determines the name under which the input will be available in template bindings. The required property indicates that the input is required which will trigger a compile-time error if it isn't passed in when the directive is used.

When a string is passed into the inputs array, it can have a format of 'name' or 'name: alias' where name is the property on the class that the directive should write to, while the alias determines the name under which the input will be available in template bindings. String-based input definitions are assumed to be optional.

Enumerates the set of event-bound output properties.

When an output property emits an event, an event handler attached to that event in the template is invoked.

The outputs property defines a set of directiveProperty to alias configuration:

• directiveProperty specifies the component property that emits events.
• alias specifies the DOM property the event handler is attached to.

Configures the injector of this directive or component with a token that maps to a provider of a dependency.

Defines the name that can be used in the template to assign this directive to a variable.

Configures the queries that will be injected into the directive.

Content queries are set before the ngAfterContentInit callback is called. View queries are set before the ngAfterViewInit callback is called.

Maps class properties to host element bindings for properties, attributes, and events, using a set of key-value pairs.

Angular automatically checks host property bindings during change detection. If a binding changes, Angular updates the directive's host element.

When the key is a property of the host element, the property value is propagated to the specified DOM property.

When the key is a static attribute in the DOM, the attribute value is propagated to the specified property in the host element.

For event handling:

• The key is the DOM event that the directive listens to. To listen to global events, add the target to the event name. The target can be window, document or body.
• The value is the statement to execute when the event occurs. If the statement evaluates to false, then preventDefault is applied on the DOM event. A handler method can refer to the $event local variable.

When present, this directive/component is ignored by the AOT compiler. It remains in distributed code, and the JIT compiler attempts to compile it at run time, in the browser. To ensure the correct behavior, the app must import @angular/compiler.

Standalone directives that should be applied to the host whenever the directive is matched. By default, none of the inputs or outputs of the host directives will be available on the host, unless they are specified in the inputs or outputs properties.

You can additionally alias inputs and outputs by putting a colon and the alias after the original input or output name. For example, if a directive applied via hostDirectives defines an input named menuDisabled, you can alias this to disabled by adding 'menuDisabled: disabled' as an entry to inputs.