Angular2, evaluate template from string inside a component
It's possible evaluate template from string in a variable?. I need place the string in the component instead of the expression, e.g.
template: "<div>{{ template_string }}</div>"
template_string contains: <b>{{ name }}</b>
and all should be evaluated to <div><b>My Name</b></div>
but I see <div>{{ template_string }}</div>
I need something like {{ template_string | eval }}
or something else to evaluate the content of the variable on current context.
It's possible? I need something to use this approach because template_string
can be changed when the component is used.
Edit1:
Angular Version: 4.0.3
E.g.
@Component({
selector: 'product-item',
template: `
<div class="product">{{ template }}</div>`,
})
export class ProductItemComponent {
@Input() name: string;
@Input() price: number = 0;
@Input() template: string = `{{ name }} <b>{{ price | currency }}</b>`;
}
Usage:
<product-item [name]="product.name" [price]="product.price"></product-item>
Expected: Product Name USD3.00
Output: {{ name }} <b>{{ price | currency }}</b>
Solution 1:
You can create your own directive that will do it:
compile.directive.ts
@Directive({
selector: '[compile]'
})
export class CompileDirective implements OnChanges {
@Input() compile: string;
@Input() compileContext: any;
compRef: ComponentRef<any>;
constructor(private vcRef: ViewContainerRef, private compiler: Compiler) {}
ngOnChanges() {
if(!this.compile) {
if(this.compRef) {
this.updateProperties();
return;
}
throw Error('You forgot to provide template');
}
this.vcRef.clear();
this.compRef = null;
const component = this.createDynamicComponent(this.compile);
const module = this.createDynamicModule(component);
this.compiler.compileModuleAndAllComponentsAsync(module)
.then((moduleWithFactories: ModuleWithComponentFactories<any>) => {
let compFactory = moduleWithFactories.componentFactories.find(x => x.componentType === component);
this.compRef = this.vcRef.createComponent(compFactory);
this.updateProperties();
})
.catch(error => {
console.log(error);
});
}
updateProperties() {
for(var prop in this.compileContext) {
this.compRef.instance[prop] = this.compileContext[prop];
}
}
private createDynamicComponent (template:string) {
@Component({
selector: 'custom-dynamic-component',
template: template,
})
class CustomDynamicComponent {}
return CustomDynamicComponent;
}
private createDynamicModule (component: Type<any>) {
@NgModule({
// You might need other modules, providers, etc...
// Note that whatever components you want to be able
// to render dynamically must be known to this module
imports: [CommonModule],
declarations: [component]
})
class DynamicModule {}
return DynamicModule;
}
}
Usage:
@Component({
selector: 'product-item',
template: `
<div class="product">
<ng-container *compile="template; context: this"></ng-container>
</div>
`,
})
export class ProductItemComponent {
@Input() name: string;
@Input() price: number = 0;
@Input() template: string = `{{ name }} <b>{{ price | currency }}</b>`;
}
Plunker Example
See also
- Angular 2.1.0 create child component on the fly, dynamically