@ViewChild('injectParameterInput', {read: ViewContainerRef}) parameterInputGroup;

    constructor(private cfr: ComponentFactoryResolver) {}

    addSourceForm = new FormGroup({
        url: new FormControl(''),
        parameters: new FormArray([])
    })

    addParameterInput() {
        const componentFactory = this.cfr.resolveComponentFactory(ParameterInputComponent)
        const compRef = this.parameterInputGroup.createComponent(componentFactory)

        let array = this.addSourceForm.controls.parameters as FormArray

        // array.push(new FormControl('')) ???

        compRef.instance.requestDestroy.subscribe(() => {
          compRef.destroy()
        })
    }