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@arniebradfo
Last active May 27, 2021 19:14
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Get a Angular component by a string corresponding to its class name
/**
* @author http://bradford.digital
* @link https://stackoverflow.com/questions/42949647/resolve-type-of-component-from-string-in-angular2
*
* Keep a registry of key:value pairs that is the string name of a component and the Component reference
* The registry is stored in an exported const named COMPONENTREGISTRY
* Add to the registry by using the registerComponent() function as an adorner. example:
* @registerComponent
* @Component({...})
* export class AnExampleComponent {...}
* Get a component by its string name by calling COMPONENTREGISTRY.getTypeFor('AnExampleComponent')
* Or get it by its template name if your following general angular naming convention COMPONENTREGISTRY.getTypeFor('app-an-example')
*
* TODO: add the html template string without guessing like we are now?
* A class couuld be obtained by calling COMPONENTREGISTRY.getTypeFor('app-an-example')
**/
interface Component { }
type ComponentClass = { new(...any: any[]): Component };
class ComponentRegistry {
registry = new Map<string, ComponentClass>();
getTypeFor(name: string): ComponentClass {
if (name.match('-'))
name = this.getComponentNameFromTemplate(name);
let componentClass: ComponentClass = this.registry.get(name);
if (componentClass == null) throw new Error(`${name} was not found in the COMPONENTREGISTRY.registry`);
return componentClass;
}
getComponentNameFromTemplate(name: string): string {
const words: string[] = name.split('-');
words.splice(0, 1); // remove the prefix
for (let i = 0; i < words.length; i++) {
const capitalized = words[i].charAt(0).toUpperCase() + words[i].slice(1);
words.splice(i, 1, capitalized);
}
const componentName = words.join('') + 'Component';
return componentName;
}
register(cls: ComponentClass): void {
this.registry.set(cls.name, cls);
}
// registerTemplateString(cls: ComponentClass): void {
// let templateString = 'app-angular-component'; // how to get this from the ComponentClass reference?
// this.registry.set(templateString, cls);
// }
}
export const COMPONENTREGISTRY = new ComponentRegistry();
export function registerComponent(componentClass: ComponentClass): void {
COMPONENTREGISTRY.register(componentClass);
}
@Resington
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Hi, Thanks for sharing your code... I have integrated your typescript code into my angular project. While running the code, I am getting this error..." MySampleComponent was not found in the COMPONENTREGISTRY.registry at ComponentRegistry.getTypeFor " . Am I doing anything wrong. Do I need to Import MySampleComponent into ComponentRegistry. If so how should I do that? Thanks in advance...

@arniebradfo
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@Resington I honestly don't remember how this works. This was written a long time ago and I was using Angular v3 (I think?). The API has probably changed a lot since then. I don't think I can help you with this. Sorry.

@Resington
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It's ok.... Arniebradfo, Thank you so much for your reply....

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