FormArray without FormControls and just strings Angular 2 -


i have 2 string arrays on backend have fill either single string or multiple strings. not key value pairs. trying push string 1 of arrays running fact not , cannot specify control: value pair.

my formarray looks 

collections: new formarray([]),

my html select strings

              <md-select placeholder="collection">             <md-option (click)="addcollectionid('one')" value="local">local</md-option>             <md-option (click)="addcollectionid('two')" value="music">music</md-option>             <md-option (click)="addcollectionid('three')" value="performing arts">performing arts</md-option>             <md-option (click)="addcollectionid('four')" value="sports">sports</md-option>             <md-option (click)="addcollectionid('five')" value="restaurants">restaurants</md-option>           </md-select>

and logic add strings formarray looks like:

  addcollectionid(id: string) { const control = <formarray>this.createcardform.controls['collections']; control.push(id);

}

i getting error 'argument of type 'string' not assignable parameter of type 'abstractcontrol'.

since cannot push control: value pair , string/strings how can push strings array while still staying in overall form?

any help/tips/suggestions appreciated.

you can use reactive forms api achieve this, recommend use angular formbuilder:

export class selectoverviewexample {   createcardform: formgroup;    foods = [     {value: 'steak-0', viewvalue: 'steak'},     {value: 'pizza-1', viewvalue: 'pizza'},     {value: 'tacos-2', viewvalue: 'tacos'}   ];    // inject form builder   constructor(private fb: formbuilder) {     // add collections form array form     this.createcardform = this.fb.group({       collections: this.fb.array([]),     });   }    // function pushed new value collections array   addcollectionid(val) {     const collections = this.createcardform.get('collections');     // add once     if (!collections.value.includes(val)) {       collections.push(this.fb.control(val));     }   } }

this way selected values added form , available under createcardform.value.collections array.

here html:

<md-select placeholder="favorite food">   <md-option [disabled]="createcardform.value.collections.includes(food.value)"               *ngfor="let food of foods"               [value]="food.value"               (click)="addcollectionid(food.value)">     {{ food.viewvalue }}   </md-option> </md-select>  <pre>{{ createcardform.value | json }}</pre>

here updated plunker forked https://material.angular.io/components/select/overview

update

here reactive form solution, without call addcollectionid() function. add reactivecollections field form group:

constructor(private fb: formbuilder) {   this.createcardform = this.fb.group({     collections: this.fb.array([]),     reactivecollections: null   }); }

add form group , control names md-select:

<form [formgroup]="createcardform">   <md-select placeholder="favorite food"               multiple="true"               formcontrolname="reactivecollections">     <md-option *ngfor="let food of foods" [value]="food.value">       {{ food.viewvalue }}     </md-option>   </md-select> </form>

plunker updated well


Comments

Post a Comment

Popular posts from this blog

angular - Ionic slides - dynamically add slides before and after -

hi i'm using ngfor create set of 3 slides while starting in middle i'm guaranteed able slide left or right on start. when slide right can simple listen reachedend , push slide array i'm looping. but have problem adding slide beginning. if same above , use e.g. array.unshift() or spread add item beginning, view think it's on position 0 , snaps view new slide. the code below work animates slide change index 1. slide = [0,1,2] //example loop slidechanged(event) { if(this.slides.isbeginning()){ this.slide = [this.slide[0]-1, ...this.slide]; this.slides.update(); this.slides.slideto(1) } } <ion-slides [initialslide]="1" (ionslidedidchange)="slidechanged($event)"> <ion-slide *ngfor="let item of slide"> <h1>slide {{item}}</h1> </ion-slide> </ion-slides> any appreciated! you can using ionslidenextend , ionslideprevend events slides . please
Read more

minify - Minimizing css files -

i want know how css files can minimized. currently, using external sites css minifier compress css files. however, after removing whitespaces, comments, etc, file sizes reduced 10-15%. how frameworks bootstrap manage make minimized versions kilobytes. as example, css is: body { background-color: #ff0; } the reduction goes 28 bytes 22 bytes other css files have lot more characters still smaller this. actually minifying code means it's remove thing code white space characters new line characters comments block delimiters it reduces amount of code has transferred on web , speed site load fastly.but unreadable format.
Read more

Add a dynamic header in angular 2 http provider -

i have http interceptor built via tutorial https://scotch.io/@kashyapmukkamala/using-http-interceptor-with-angular2 the problem need have dynamic header changes automatically once changes 'mode' in app. service able tell interceptor change header, or have interceptor pull header (which string)from service each request. able throwing away patch method, call http.patch('new header string') set header string. call in service controls 'mode' setting. wondering if there way interceptor pull recent value service each request or if can add method http provider via interceptor? i've tried call service in interceptor each request returns undefined. because creating new instance of service or copying value before service fired , loaded/changed data. i don't want pass header string every http provider call because defeats purpose of having interceptor, id able set once changes or have provider fetch service before makes request. tl;dr : need add autom
Read more