Encountering issues with resolving all parameters when attempting to dynamically generate a component in Angular

Question

Encountering issues with resolving all parameters when attempting to dynamically generate a component in Angular

As I attempt to dynamically insert a BlockComponent into a GridLayoutComponent, an error is thrown:

Uncaught Error: Can't resolve all parameters for BlockComponent: (?, [object Object])

. This issue arises upon page load and stems from the addBlock function in the GridLayoutComponent. My knowledge of dynamically adding components in Angular is limited, and the tutorials I've come across have been overly simplistic, lacking detailed instructions on dealing with constructors. Below is my code snippet:

grid-layout.component.ts:

// Code here

block.components.ts:

// Code here

I've noticed that the grid attribute of the GridLayoutComponent does not possess a createComponent method. Could someone enlighten me on the correct way to dynamically create a component in Angular and append it to the page?

EDIT:
Pre-existing BlockComponents function without any issues.
grid-layout.component.html:

// HTML code here

EDIT 2:
My code can be found on GitHub (link) and accessed on StackBlitz (link)

EDIT 3:
I have removed the @Host parameter to access the GridLayoutComponent from within the BlockComponent, retrieving it instead from the EditGridService. While this workaround functions, I suspect there must be a more appropriate solution to managing a component factory with a @Host parameter.

angular typescript

Answer 1

Answer №1

The resolveComponentFactory function requires a component to be passed in (refer to the official documentation here):

const factory = this.resolver.resolveComponentFactory(MyComponent)

Upon examining the code, it appears that MyComponent is not actually a component but rather a simple class with a property parent, which itself is a component, but this does not establish inheritance.

It also seems strange to export MyComponent and then import Block.

Answer 2

The resolveComponentFactory function requires a component to be passed in (refer to the official documentation here):

const factory = this.resolver.resolveComponentFactory(MyComponent)

Upon examining the code, it appears that MyComponent is not actually a component but rather a simple class with a property parent, which itself is a component, but this does not establish inheritance.

It also seems strange to export MyComponent and then import Block.

Answer 3

Answer №2

Angular simplifies the process with a directive called ngComponentOutlet.

<ng-container *ngComponentOutlet="BlockComponent"></ng-container>

In your App.module.ts file, remember to include BlockComponent in the entryComponents array and import it into the TypeScript file as well.

You can also achieve the same result in a more complex manner. In your HTML file, add an ng-container:

<ng-container #viewcontainer></ng-container>

In your TypeScript file, add:

@ViewChild('viewcontainer', { read: ViewContainerRef }) vc: ViewContainerRef;
constructor(private resolver: ComponentFactoryResolver) {}
  ngOnInit() {
    this.vc.clear();
      const factory = this.resolver.resolveComponentFactory(BlockComponent);
      const dynamicComponent = factory.create(this.vc.parentInjector);
      this.vc.insert(dynamicComponent.hostView);
  }

Both methods achieve the same outcome, but the first one is easier. Just don't forget to add the component to the entry component array. Good luck!

For more information, check out:

Answer 4

Angular simplifies the process with a directive called ngComponentOutlet.

<ng-container *ngComponentOutlet="BlockComponent"></ng-container>

In your App.module.ts file, remember to include BlockComponent in the entryComponents array and import it into the TypeScript file as well.

You can also achieve the same result in a more complex manner. In your HTML file, add an ng-container:

<ng-container #viewcontainer></ng-container>

In your TypeScript file, add:

@ViewChild('viewcontainer', { read: ViewContainerRef }) vc: ViewContainerRef;
constructor(private resolver: ComponentFactoryResolver) {}
  ngOnInit() {
    this.vc.clear();
      const factory = this.resolver.resolveComponentFactory(BlockComponent);
      const dynamicComponent = factory.create(this.vc.parentInjector);
      this.vc.insert(dynamicComponent.hostView);
  }

Both methods achieve the same outcome, but the first one is easier. Just don't forget to add the component to the entry component array. Good luck!

For more information, check out:

Encountering issues with resolving all parameters when attempting to dynamically generate a component in Angular

Answer №1

Answer №2

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