ionic4-auto-complete

About

This is a component based on Ionic's search-bar component, with the addition of auto-complete ability. This component is super simple and light-weight. Just provide the data, and let the fun begin.

This is a free software please feel free to contribute! :)

Installation

TODO: $ npm install ionic4-auto-complete --save

Usage guide

Open angular.json and add the following to the assets array:

{
  "glob": "**/*",
  "input": "node_modules/ionic4-auto-complete/assets/",
  "output": "./assets/"
}

Open app.module.ts and add the following import statement:

import { AutoCompleteModule } from 'ionic4-auto-complete';

Then, add the AutoCompleteModule to the imports array:

@NgModule({
  declarations: [
    MyApp,
    HomePage,
    TabsPage,
    MyItem
  ],
  imports: [
    BrowserModule,
    AutoCompleteModule,
    FormsModule,
    HttpModule,
    IonicModule.forRoot(MyApp)
  ],
  ...
  ...
})
export class AppModule {}

Now let's import the styling file. Open app.scss and add the following:

@import "../../node_modules/ionic4-auto-complete/auto-complete";

Now, let's add the component to our app!

Add the following tag to one of your pages, in this example I am using the Homepage:

<ion-auto-complete></ion-auto-complete>

Now let's see what wev'e done so far by running ionic serve.

Now, when everything is up and running you should see a nice search-bar component. Open the developer console and try to type something.

Oh no! something is wrong. You probably see an excpetion similiar to :

EXCEPTION: Error in ./AutoCompleteComponent class AutoCompleteComponent - inline template:1:21

This is totally cool, for now. The exception shows up since we did not provide a dataProvider to the autocomplete component.

How does it work? So, ionic4-auto-complete is not responsible for getting the data from the server. As a developer, you should implement your own service which eventually be responsible to get the data for the component to work, as well we determing how many results to show and/or their order of display.

So there are two possibilities to provide data:

1. A simple function that returns an Array of items
2. An instance of 'AutocompleteService' (specified below)

Let's start by creating the service:

import {AutoCompleteService} from 'ionic4-auto-complete';
import { Http } from '@angular/http';
import {Injectable} from "@angular/core";
import 'rxjs/add/operator/map'

@Injectable()
export class CompleteTestService implements AutoCompleteService {
  labelAttribute = "name";

  constructor(private http:Http) {

  }
  getResults(keyword:string) {
    return this.http.get("https://restcountries.eu/rest/v1/name/"+keyword)
      .map(
        result =>
        {
          return result.json()
            .filter(item => item.name.toLowerCase().startsWith(keyword.toLowerCase()) )
        });
  }
}

By implementing an AutoCompleteService interface, you must implement two properties:

1. labelAttribute [string] - which is the name of the object's descriptive property (leaving it null is also an option for non-object results)
2. getResults(keyword) [() => any] - which is the method responsible for getting the data from server.

The getResults method can return one of:

• an Observable that produces an array
• a Subject (like an Observable)
• a Promise that provides an array
• directly an array of values

In the above example, we fetch countries data from the amazing https://restcountries.eu/ project, and we filter the results accordingly.

Important! the above example is just an example! the best practice would be to let the server to the filtering for us! Here, since I used the countries-api, that's the best I could do.

Now, we need to let ionic4-auto-complete that we want to use CompleteTestService as the data provider, edit home.ts and add private completeTestService: CompleteTestService to the constructor argument list. Should look like that:

import { Component } from '@angular/core';
import { NavController } from 'ionic-angular';
import { CompleteTestService } from '../../providers/CompleteTestService';

@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {

  constructor(public navCtrl: NavController, public completeTestService: CompleteTestService) {

  }

}

Than, in home.html modify <ion-auto-complete>:

<ion-auto-complete [dataProvider]="completeTestService"></ion-auto-complete>

Now, everything should be up and ready :)

---

Use auto-complete in Angular FormGroup

Use labelAttribute as both label and form value (default behavior)

By default, if your dataProvider provides an array of objects, the labelAttribute property is used to take the good field of each object to display in the suggestion list. For backward compatibility, if nothing is specified, this attribute is also used to grab the value used in the form.

The page should look like this:

import { Component } from '@angular/core';
import { NavController } from 'ionic-angular';
import { CompleteTestService } from '../../providers/CompleteTestService';
import { FormGroup, Validators, FormControl } from '@angular/forms'


@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {
  myForm: FormGroup

  constructor(public navCtrl: NavController, public completeTestService: CompleteTestService) {
  }

  ngOnInit(): void {
    this.myForm = new FormGroup({
      country: new FormControl('', [
        Validators.required
      ])
    })
  }

  submit(): void {
    let country = this.myForm.value.country
  }

}

Then, in home.html place the auto-complete component in the form group and add the formControlName attribute:

<form [formGroup]="myForm" (ngSubmit)="submit()" novalidate>
  <div class="ion-form-group">
    <ion-auto-complete [dataProvider]="completeTestService" formControlName="country"></ion-auto-complete>
  </div>
  <button ion-button type="submit" block>Add country</button>
</form>

Now when the submit method is called, the country is the selected country name.

How to use another field as form value ?

To indicate that you don't want the label as value but another field of the country object returned by the REST service, you can specify the attribute formValueAttribute on your dataProvider. For example, we want to use the country numeric code as value and still use the country name as label.

Let's update the service (just declare formValueAttribute property):

import {AutoCompleteService} from 'ionic4-auto-complete';
import { Http } from '@angular/http';
import {Injectable} from "@angular/core";
import 'rxjs/add/operator/map'

@Injectable()
export class CompleteTestService implements AutoCompleteService {
  labelAttribute = "name";
  formValueAttribute = "numericCode"

  constructor(private http:Http) {
  }

  getResults(keyword:string) {
    return this.http.get("https://restcountries.eu/rest/v1/name/"+keyword)
      .map(
        result =>
        {
          return result.json()
            .filter(item => item.name.toLowerCase().startsWith(keyword.toLowerCase()) )
        });
  }
}

Now when the submit method is called, the country is the selected country numericCode. The name is still used as the label.

How to use the whole object as form value ?

Simply set formValueAttribute to empty string:

import {AutoCompleteService} from 'ionic4-auto-complete';
import { Http } from '@angular/http';
import {Injectable} from "@angular/core";
import 'rxjs/add/operator/map'

@Injectable()
export class CompleteTestService implements AutoCompleteService {
  labelAttribute = "name";
  formValueAttribute = ""

  constructor(private http:Http) {
  }

  getResults(keyword:string) {
    return this.http.get("https://restcountries.eu/rest/v1/name/"+keyword)
      .map(
        result =>
        {
          return result.json()
            .filter(item => item.name.toLowerCase().startsWith(keyword.toLowerCase()) )
        });
  }
}

---

Styling

Currently for best visual result, use viewport size / fixed size (pixels) if you are interested in resizing the component:

ion-auto-complete {
  width: 50vw;
}

Custom Templates

Ionic4-auto-complete also supports custom templates for the list items. Actually, you can display any attribute associated with your data items by simply accessing it from the data input class member in the template.

For example:

Let's assume that in addition to the country name, we also wish to display the country flag. For that, we use the ng-template directive, which let's us pass the template as an input to the component.

On the page where your ion-auto-complete is located:

<ng-template #withFlags let-attrs="attrs">
  <img src="assets/image/flags/{{attrs.data.name}}.png" class="flag" /> <span [innerHTML]="attrs.data.name | boldprefix:attrs.keyword"></span>
</ng-template>
<ion-auto-complete [dataProvider]="service" [template]="withFlags"></ion-auto-complete>

Please note that you must add the let-attrs="attrs" attribute to your template.

With that, you can easily of different templates for different components!

Events

itemSelected($event) - fired when item is selected (clicked)
itemsShown($event) - fired when items are shown
itemsHidden($event) - fired when items are hidden
ionAutoInput($event) - fired when user inputs
autoFocus($event) - fired when the input is focused
autoBlur($event) - fired when the input is blured

Searchbar options

Ionic4-auto-complete supports the regular Ionic's Searchbar options, which are set to their default values as specified in the docs.

You can override these default values by adding the [options] attribute to the <ion-auto-complete> tag, for instance:

  <ion-auto-complete [dataProvider]="someProvider" [options]="{ placeholder : 'Lorem Ipsum' }"></ion-auto-complete>

Options include, but not limited to:

1. debounce (default is 250)
2. autocomplete ("on" and "off")
3. type ("text", "password", "email", "number", "search", "tel", "url". Default "search".)
4. placeholder (default "Search")

Component specific options

In addition to the searchbar options, ion-auto-complete also supports the following option attributes:

• [template] (TemplateRef) - custom template reference for your auto complete items (see below)
• [showResultsFirst] (Boolean) - for small lists it might be nicer to show all options on first tap (you might need to modify your service to handle an empty keyword)
• [alwaysShowList] (Boolean) - always show the list - defaults to false)
• [hideListOnSelection] (Boolean) - if allowing multiple selections, it might be nice not to dismiss the list after each selection - defaults to true)

Will set the Searchbar's placeholder to Lorem Ipsum

Accessing Searchbar component

By using the @ViewChild() decorator, and the built-in getValue() method we can easily access the actual value in the searchbar component. Just define a new property within the desired page, for instance (the chosen names are arbitrary):

  @ViewChild('searchbar')
  searchbar: AutoCompleteComponent;

And then, in the component tag we need to add #searchbar:

<ion-auto-complete [dataProvider]="provider" #searchbar></ion-auto-complete>

Available methods:

1. getValue(): this.searchbar.getValue() - get the string value of the selected item
2. getSelection(): this.searchbar.getSelection() - get the selected object
3. setFocus(): this.searchbar.setFocus() - focus on searchbar

Contributing

To contribute, clone the repo. Then, run npm install to get the packages needed for the library to work. Running gulp will run a series of tasks that builds the files in /src into /dist. Replace the /dist into whatever Ionic application's node_modules where you're testing your changes to continuously improve the library.

Versioning

Follows Semantic Versioning (2.0.0)

NPM Release

Run npm publish from dist/ directory.

Thanks

kadoshms bushybuffalo