What I'm trying to do:
Plnkr Example -> enter link description here
In the example, you will see the AddItem
method
addItem(componentName:string):void{
let compFactory: ComponentFactory;
switch(componentName){
case "image":
compFactory = this.compFactoryResolver.resolveComponentFactory(PictureBoxWidget);
break;
case "text":
compFactory = this.compFactoryResolver.resolveComponentFactory(TextBoxWidget);
break;
}
//How can I resolve a component based on string
//so I don't need to hard cost list of possible options
this.container.createComponent(compFactory);
}
The "compFactoryResolver:ComponentFactoryResolver" is injected in the contructor.
As you will note, having to hard code every permutation in a switch statement is less than ideal.
when logging the ComponentFactoryResolver to the console, I've observed that it contains a Map with the various factories.
CodegenComponentFactoryResolver {_parent: AppModuleInjector, _factories: Map}
However, this map is a private and can't be easily accessed (from what I can tell).
Is there a better solution then somehow rolling my own class to get access to this factory list?
I've seen a lot of messages about people trying to create dynamic components. However, these are often about creating components at run time. the components in question here are already pre-defined, I am stuck trying to access factories using a string as a key.
Any suggestions or advice are much appreciated.
Thank you kindly.
It's either defining a map of available components,
const compMap = {
text: PictureBoxWidget,
image: TextBoxWidget
};
Or defining identifiers as static class property that will be used to generate a map,
const compMap = [PictureBoxWidget, TextBoxWidget]
.map(widget => [widget.id, widget])
.reduce((widgets, [id, widget]) => Object.assign(widgets, { [id]: widget }), {});
The map is then used like
let compFactory: ComponentFactory;
if (componentName in compMap) {
compFactory = this.compFactoryResolver.resolveComponentFactory(compMap[componentName]);
} else {
throw new Error(`Unknown ${componentName} component`);
}
There's no way how component classes can be magically identified as strings, because they aren't resolved to strings in Angular 2 DI (something that was changed since Angular 1, where all DI units were annotated as strings).
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With