Multiple instance of angular 4 directive called from a component mesed up the input values

Question

I have a component in angular 4 that is called three times. In template metadata I have a div with a directive with some bindings like this.

@import {gServ} from '../gServ.service';

@Component: ({
   selector: 'sr-comp',
   template: `<div gDirective [cOptions]="dataChart">`
})

export class SGComponent implements OnInit {
    @Input('report') public report: IReportInstance;
    cOptions:any;

    constructor(private gServ: gServ) {
    }

    ngOnInit(){

        this.cOptions = {};
        this.cOptions = this.gServ.objectMerge(this.gServ.defaultOpt, this.report.opt);

        //this.report.opt is binded to a component when is instantiated.
        //this.gServ.objectMerge is a function that merge the two objects
    }
}

this.cOptions change for every instance of the component, then in the directive I have this:

import { Directive, ElementRef, HostListener, Input, OnInit } from '@angular/core';

@Directive({
  selector: '[gDirective]'
})
export class SGDirective implements OnInit {
  public _element: any;
  @Input() public cOptions: string;

  constructor(public element: ElementRef) {
    this._element = this.element.nativeElement;
  }

  ngOnInit() {
    console.log(this.cOptions);
  }
}

The problem is that console.log(this.cOptions); always print the same object, even when component set cOptions with diferent values in ngOnInit method of the compnent.

Do you have some idea what is wrong?

Answer 1

Your component property binding [cOptions]="dataChart" doesn't look good, reason being your dataChart is not even defined. it should be like [DIRECTIVE_PROPERTY]="COMPONENT_PROPERTY" and your COMPONENT_PROPERTY is not even defined in SGComponent component class.

Your component class should be something like this:

@import {gServ} from '../gServ.service';

@Component: ({
   selector: 'sr-comp',
   template: `<div gDirective [cOptions]="Options">`
})

export class SGComponent implements OnInit {
    @Input('report') public report: IReportInstance;
    Options:any;

    constructor(private gServ: gServ) {
    }

    ngOnInit(){
        this.Options = {};
        this.Options = this.gServ.objectMerge(this.gServ.defaultOpt, this.report.opt);
    }
}