Accessing each part of an array using (change) Angular 5

angular 4 ngfor multiple arrays
ngfor angular 7
angular list of objects
ngfor trackby
ngfor not working
angular 4 ngfor example
ngfor not updating when array changes
angular 4 ngfor number of times

I am trying to create a box, where you can click on each option within it and it will filter through data coming from firebase database. So far, I have it working where you can click on each of them. However, I can only get it to perform one task.

Each of the options comes from this array:

items: number[] = [1,2,3,4,5,6,7,8,9];

and the filtering comes from this function:

filterByBedrooms(bedrooms: number) {
   this.bedFilter.next(bedrooms);
   console.log('clicked')
 }

and then I have this form where I call the function:

 <form  #fSearchPropertiesByBedrooms (change)="filterByBedrooms(items[4])">
          <select class="form-control form-control-lg small-drop-down" type="number"  [(ngModel)]="bedrooms" name="bedrooms">
            <option [ngValue]="undefined" selected>Beds</option>
            <option *ngFor="let item of items" [ngValue]="item"> <button> {{item}} Bed </button> </option>
          </select>
          <!-- <button type="submit" class="button button-primary button-xs button-green">Submit</button> -->
        </form>

Now obviously in this I bind to the function and the array like so:

(change)="filterByBedrooms(items[4])" 

I am aware that what I need to do is somehow bind to it like this:

(change)="filterByBedrooms(item)"

However, the *ngFor comes after this part, so it does not work.

My question is, how do I bind (change) to each of the options (coming from the array) within my select box and not just one part of the array?

You don't bind your event to your options, you bind it to your select.

You can see it for yourself : the select carries the ngModel attribute, not the options.

See it as an input of type text, with predefined results.

So simply call your method with the bound ngModel like this.

<select
  class="form-control form-control-lg small-drop-down"
  type="number"
  [(ngModel)]="bedrooms"
  name="bedrooms"
  (change)="filterByBedrooms(bedrooms)">

Angular NgFor: Everything you need to know, All we need to do is to tell the directive, which array to use. Furthermore, when a element changes its position in the array, angular notices that and only changes the position of the one DOM-element. They are very fast when it comes to accessing data by a key. SINETHEMBA PAULA5 months. As of Angular 5.0, the older Http service still works, but it's deprecated and has been removed in Angular 6.0. The code samples in this post are compatible with Angular 4.3 and 5.x (and 6.x with rxjs-compat). If your project is still using Angular 4.2 or lower, including Angular 2, see my previous posts on making API calls with the Http service.

You can do like this, just declare an identifier for select and use the value in your method.

<form  #fSearchPropertiesByBedrooms (change)="filterByBedrooms(bedrooms.value)">
              <select class="form-control form-control-lg small-drop-down" type="number"  [(ngModel)]="bedrooms" name="bedrooms" #bedrooms>
                <option [ngValue]="undefined" selected>Beds</option>
                <option *ngFor="let item of items" [ngValue]="item"> <button> {{item}} Bed </button> </option>
              </select>
              <!-- <button type="submit" class="button button-primary button-xs button-green">Submit</button> -->
            </form>

Also I noticed you have binded the variable bedrooms to select. That means that you have that variable in your controller so you can redefine your filterByBedrooms method to something like this

filterByBedrooms() {
   this.bedFilter.next(this.bedrooms);
   console.log('clicked')
 }

If you are using the second example than your form will look like this

<form  #fSearchPropertiesByBedrooms (change)="filterByBedrooms()">
                  <select class="form-control form-control-lg small-drop-down" type="number"  [(ngModel)]="bedrooms" name="bedrooms" >
                    <option [ngValue]="undefined" selected>Beds</option>
                    <option *ngFor="let item of items" [ngValue]="item"> <button> {{item}} Bed </button> </option>
                  </select>
                  <!-- <button type="submit" class="button button-primary button-xs button-green">Submit</button> -->
                </form>

Displaying data in views, Then modify the app.component.ts file by changing the template and the body of the component. In either style, the template data bindings have the same access to the component's properties. The following example uses the directive to show all of the values in an array property. Version 9.1.5-local+sha.​c8c2272a9f. Adding or removing controls from a form arraylink. To change the controls in the array, use the push, insert, removeAt or clear methods in FormArray itself. These methods ensure the controls are properly tracked in the form's hierarchy.

I would suggest you to use (ngModelChange) event as far as you use ngModel binding, so the code should look like:

 <form  #fSearchPropertiesByBedrooms>
      <select class="form-control form-control-lg small-drop-down" type="number"  [(ngModel)]="bedrooms" name="bedrooms" (ngModelChange)="filterByBedrooms($event)">
        <option [ngValue]="undefined" selected>Beds</option>
        <option *ngFor="let item of items" [ngValue]="item"> <button> {{item}} Bed </button> </option>
      </select>
      <!-- <button type="submit" class="button button-primary button-xs button-green">Submit</button> -->
    </form>

And actually I'm not sure you need a form for this particular control as I see you commented the submit button, so this can be simplified to:

  <select class="form-control form-control-lg small-drop-down" type="number"  [(ngModel)]="bedrooms" name="bedrooms" (ngModelChange)="filterByBedrooms($event)">
    <option [ngValue]="undefined" selected>Beds</option>
    <option *ngFor="let item of items" [ngValue]="item"> <button> {{item}} Bed </button> </option>
  </select>

Don't forget to add value check on filterByBedrooms function as in your case it can by invoked with undefined value.

Angular ngFor, Angular ngFor - Learn all Features including trackBy, why is it not only for {id: 5, name:'BatGirl'}, To use ngFor , let's create a component so that we can have a the loop, you would not be able to access it outside the ngFor section. With this change, the HTML generated now looks like the following:  Do you see what happened here? Turns out the QueryList is a class that is part of Angular and is itself an Iterable! So although we can use it programmatically in the component class, we can also pass it directly to ngFor and iterate over it directly. And the same could be done with any other Iterable in our program.

Biding to array elements using ngModel and inside a ngFor · Issue , [X] bug report I'm using ngModel to bind values of an array into to number inputs. After some time making changes to the inputs, the bindings stop working properly Code Issues 2,834 Pull requests 592 Projects 5 Actions Security 0 Pulse Pls refer this link Angular 2 get Input element value Its not still wrk. Angular has a very rich API with many functions and directives. forEach is a function reside in `ng` Module. forEach invokes the iterator function for each item in an array or object. It is similar to `for in’`in javascript. ‘for in’ is used for objects while foreach can be used for both arrays and objects.

NgFor • Angular, We use the NgFor directive to loop over an array of items and create multiple elements The template element is the element the directive is attached to. NgFor is a structural directive, meaning that it changes the structure of the DOM . It's point is to repeat a given HTML template once for each value in an array, each time  I'm using ngModel to bind values of an array into to number inputs. After some time making changes to the inputs, the bindings stop working properly updating the wrong inputs. But the issue only seems to happen on the inputs generated inside a ngFor.

TypeScript Arrays, How to Change the Style of <a> Tag Title Attribute ? File uploading in React. We can access the array elements by using the 'FOR' loop: filter_none. edit close. To prevent that behavior, we can help angular with the identification of each object, by providing a so-called trackBy function. With this function, we can tell angular, which properties cause an object to be unique. In the case of our example, we can use the guid field to identify each object. Because this value does (should) not change when