NgSwitch
Adds / removes DOM sub-trees when the nest match expressions matches the switch expression.
NgModule
Selectors
[ngSwitch]
Properties
Property | Description |
---|---|
@Input()
|
Write-only. |
Description
NgSwitch
stamps out nested views when their match expression value matches the value of the
switch expression.
In other words:
- you define a container element (where you place the directive with a switch expression on the
[ngSwitch]="..."
attribute) - you define inner views inside the
NgSwitch
and place a*ngSwitchCase
attribute on the view root elements.
Elements within NgSwitch
but outside of a NgSwitchCase
or NgSwitchDefault
directives will
be preserved at the location.
The ngSwitchCase
directive informs the parent NgSwitch
of which view to display when the
expression is evaluated.
When no matching expression is found on a ngSwitchCase
view, the ngSwitchDefault
view is
stamped out.
<container-element [ngSwitch]="switch_expression">
<some-element *ngSwitchCase="match_expression_1">...</some-element>
<some-element *ngSwitchCase="match_expression_2">...</some-element>
<some-other-element *ngSwitchCase="match_expression_3">...</some-other-element>
<ng-container *ngSwitchCase="match_expression_3">
<!-- use a ng-container to group multiple root nodes -->
<inner-element></inner-element>
<inner-other-element></inner-other-element>
</ng-container>
<some-element *ngSwitchDefault>...</some-element>
</container-element>