Generic type ‘ɵɵdirectivedeclaration’ requires 6 type argument(s).

The error message “generic type ‘ɵɵdirectivedeclaration’ requires 6 type argument(s)” occurs when using the Angular compiler’s directive declaration function without providing the necessary type arguments.

In Angular, the ‘ɵɵdirectivedeclaration’ function is used to define directives. It expects 6 type arguments to be passed in, which define the types for the directive’s inputs, outputs, and host bindings.

Here is an example of how to use the ‘ɵɵdirectivedeclaration’ function correctly:

    
      import { Directive } from '@angular/core';
      
      @Directive({
        selector: '[myDirective]'
      })
      export class MyDirective {
        constructor() { }
        
        static ngDirectiveDef = ɵɵdirectivedeclaration(
          // Type arguments
          MyDirective,
          [
            // Inputs
            { type: 'text', decorator: 'myInput' },
            
            // Outputs
            { type: 'text', decorator: 'myOutput' },
            
            // Host bindings
            { type: 'text', decorator: 'myHostBinding' }
          ]
        );
      }
    
  

In the example above, we define a directive called ‘MyDirective’ and provide the required type arguments to the ‘ɵɵdirectivedeclaration’ function. We specify the types for the inputs, outputs, and host bindings using objects with the ‘type’ and ‘decorator’ properties.

This ensures that the Angular compiler correctly generates the directive’s metadata, allowing it to be used in templates and properly handle input/output bindings.