Search Exact String using custom pipe in Angular 8 - javascript

I have created a custom pipe in order to filter my data. This is my pipe code
import { Pipe, PipeTransform } from '#angular/core';
#Pipe({
name: 'filterAll'
})
export class SpecialPipe implements PipeTransform {
transform(value: any, searchText: any): any {
if(!searchText) {
return value;
}
return value.filter((data) => JSON.stringify(data).toLowerCase().includes(searchText) );
}
}
This filter is totally working well, but my requirement is to search the exact string. I have to return the values begins with my searchText (not included). I have also tried .startsWith(), which is also not working. Is there any way to achive this?

startsWith is what you're looking for.
Here's the working snippet:
import { Pipe, PipeTransform } from '#angular/core';
#Pipe({
name: 'filter',
})
export class FilterPipe implements PipeTransform {
transform(items: any[], filterdata: string): any[] {
if (!items) return [];
if (!filterdata) return items;
filterdata = filterdata.toString().toLowerCase();
return items.filter((it) => {
return it.name.toLowerCase().startsWith(filterdata);
});
}
}
Working StackBlitz demo

Related

How do you filter an Observable with form input?

I have a component with this "countries$" variable:
countries$!: Observable<Country[]>;
that I'm populating with this data in an "ngOnInit" like this:
ngOnInit(){
this.countries$ = this.apiService.getAllCountries();
}
and I'm accessing this variable/Observable in the html template like this:
<div>
<app-country-card *ngFor="let country of countries$ | async" [country]="country"></app-country-card>
</div>
I want to include a search bar that filters the countries down to whatever is typed in.
I thought I could use the filter function inside a pipe like this:
searchFilterCountries(searchTerm: string){
this.countries$.pipe(filter((country: any) => country.name.common.toLowerCase().includes(searchTerm.toLowerCase())))
}
and put the input in the html template like this:
<input type="text" class="form-control" (input)="searchFilterCountries($event.target.value)"/>
so that the filter function would fire every time theres an input, narrowing down the list of countries on display.
This doesn't work however. I'm getting the typescript error:
Object is possibly 'null'.ngtsc(2531)
Property 'value' does not exist on type 'EventTarget'.ngtsc(2339)
Then I found a "sample" of a working filtered list here on Material UI
https://material.angular.io/components/autocomplete/examples (The FILTER one)
I attempted to implement this and came up with this code:
export class HomeComponent {
countries$!: Observable<Country[]>;
myControl = new FormControl('');
constructor(private apiService: ApiService) { }
ngOnInit(){
this.countries$ = this.apiService.getAllCountries();
}
private _filter(value: string): Observable<Country[]> {
const filterValue = value.toLowerCase();
return this.countries$.pipe(filter(option => option.name.common.toLowerCase().includes(filterValue))) <----ERROR #2
}
}
It doesn't work however. I think because the values are observables, not the data inside the observable.
I have squiggly lines showing a TS error under the under the "name" property in "option.name.common" saying:
option.name.common TS error
Property 'name' does not exist on type 'Country[]'
If I do this instead though:
option => option[0].name.common.toLowerCase().includes(filterValue)))
the error goes away, but I wouldn't be able to search all the values if I did that.
Am I on the right track here? Am I using the right operators? How do I fix the TS errors? I'm new to angular and don't know all the operators available. If I use mergeMap/switchMap will that solve my problem? If I do fix the typescript errors would it even work? Or is my approach wrong?
Can somebody help me get this working?
I would like to expand on your current code and suggest some changes like this:
export class HomeComponent {
allCountries: Country[] = [];
countries$!: Observable<Country[]>;
myControl = new FormControl('');
constructor(private apiService: ApiService) {}
ngOnInit() {
this.apiService
.getAllCountries()
.subscribe((countries) => (this.allCountries = countries));
this.countries$ = combineLatest({
searchTerm: this.myControl.valueChanges.pipe(startWith('')),
countries: this.apiService
.getAllCountries()
.pipe(tap((countries) => (this.allCountries = countries))),
}).pipe(map(({ searchTerm }) => this._filter(searchTerm)));
}
private _filter(value: string | null): Country[] {
if (value === null) {
return this.allCountries;
}
const filterValue = value?.toLowerCase();
return this.allCountries.filter((country) =>
country.name.common.toLowerCase().includes(filterValue)
);
}
}
So we're keeping the original country list in a separate variable, and we are using the form control's valueChange event to filter the countries that we need to display.
The template should look like this:
<input type="text" [formControl]="myControl" />
<div *ngFor="let country of countries$ | async">
<div>Name: {{ country.name.common }}</div>>
</div>
Example pipe
import { Pipe, PipeTransform } from '#angular/core';
import { Country } from './country';
#Pipe({
name: 'filterList',
})
export class FilterListPipe implements PipeTransform {
transform(countries: Country[]|null, searchText: string): Country[] {
if(!countries) return []
return countries.filter(country=>country.name.indexOf(searchText) != -1);
}
}
app.component.html
<form [formGroup]="controlsGroup">
<input type="text" formControlName="searchInput"/>
<div *ngFor="let country of countries | async | filterList:searchText">
<div>Name: {{country.name}}</div>
<div>Ranking: {{country.ranking}}</div>
<div>Metric: {{country.metric}}</div>
</div>
</form>
app.component.ts
import { Component } from '#angular/core';
import { FormBuilder, FormControl, FormGroup } from '#angular/forms';
import { Observable, of } from 'rxjs';
import { Country } from './country';
#Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent {
title = 'piper-example-app';
searchText = ''
controlsGroup: FormGroup
constructor(public fb:FormBuilder){
this.controlsGroup = fb.group({
searchInput: new FormControl('')
})
this.controlsGroup.get('searchInput')?.valueChanges.subscribe(value => this.searchText=value)
}
countries: Observable<Country[]> = of([{
name: 'United States of America',
ranking: 1,
metric: 'burgers per capita'
},
{
name: 'China',
ranking: 9000,
metric: 'power level lower bound'
}])
}
Admittedly I'm doing a few things that are "dirty" here where filtering the incoming observable stream of arrays of countries might be a bit more efficient. Also note you'd need to still expand the filter function to check all the properties (can use for(prop in obj) type loop to iterate over all properties to see if any of them matches the searchText or adjust the criteria as see fit.
Bit more of a complete example showing the filter part with different types of properties being filtered slightly differently:
filter-list.pipe.ts (alternative)
import { Pipe, PipeTransform } from '#angular/core';
import { Country } from './country';
#Pipe({
name: 'filterList',
})
export class FilterListPipe implements PipeTransform {
transform(countries: Country[]|null, searchText: string): Country[] {
if(!countries) return []
return countries.filter(country => {
let foundMatch = false;
let property: keyof typeof country
for(property in country) {
if(typeof country[property] === 'string') {
if((country[property] as string).indexOf(searchText) != -1)
foundMatch = true
}else {
if((country[property] as number) == parseInt(searchText))
foundMatch = true
}
}
return foundMatch
});
}
}

Javascript function .filter() not working on Iphone?

I am working in Angular 11 and facing an issue that when I try to filter the array using search filter pipe (custom pipe) then it won't work on iPhone.
// customSearch pipe
import { Pipe, PipeTransform } from "#angular/core";
#Pipe({
name: "customSearch"
})
export class CustomSearchPipe implements PipeTransform {
/** Function to filter the data **/
transform(items: any[], filter: Object): any {
if (!items || !filter) {
return items;
}
return items.filter(
item => item.location.location_name.toLowerCase().indexOf(filter) > -1
);
}
}
You can check the issue here https://stackblitz.com/edit/angular-ivy-ubizpu?file=src/app/CustomSearchPipe.pipe.ts
Any kind of help is appreciable.

Unable to do searching using custom pipe created in angular 7

How can i search in angular 7 using pipe (like filter in angular 1) ? Below is the code which i tried.But that returns only if exact match is there. But i need results which contains that word.
import { Pipe, PipeTransform } from '#angular/core';
#Pipe({
name: 'search',
pure:true
})
export class SearchPipe implements PipeTransform {
transform(data: any,searchTxt:string): any {
if(!data || !searchTxt)
{
return data;
}
return data.filter(function(x) {
return x.name ==searchTxt}) ;
}`
}
i tried below code also but doesn't work
return data.filter(x=>x.name.toString().toLowerCase().indexof(searchTxt.toLowerCase()) !== -1)
This throws error: x.name.indexof is not a function
How can i do contains search using javascript\angular ?
You should be using indexOf instead of === or indexof(which I think is a typo in your code).
Plus you should not be using a pipe to filter values. Here's why Angular doesn't recommend using pipes to filter or sort values.
Angular doesn't offer such pipes because they perform poorly and prevent aggressive minification. Both filter and orderBy require parameters that reference object properties. Read more about that here.
That being said, you can basically write the logic to filter data, right inside your Component:
Here, give this a try:
import { Component } from "#angular/core";
import { HttpClient } from "#angular/common/http";
#Component({
selector: "app-root",
templateUrl: "./app.component.html",
styleUrls: ["./app.component.css"]
})
export class AppComponent {
users = [];
filteredUsers = [];
constructor(private http: HttpClient) {}
ngOnInit() {
this.http
.get("https://jsonplaceholder.typicode.com/users")
.subscribe((users: any[]) => {
this.users = users;
this.filteredUsers = [...this.users];
});
}
onSearchTextChange(searchString) {
this.filteredUsers = [
...this.users.filter(user => user.name.indexOf(searchString) > -1)
];
}
}
Here's a Working CodeSandbox Sample for your ref.

How can I execute action after data-bind in Angular 2?

I'm developing an Angular 2 SPA. My application is composed by:
One component
One directive
I've builded one directive that format text input using onfocus and onblur events. On focus event remove dots to text value, on blur event add thousand dots to text value.
Following component's code:
<div>
<input id="input" [(ngModel)]="numero" InputNumber />
</div>
Following component's TypeScript code:
import { Component } from '#angular/core';
#Component({
selector: 'counter',
templateUrl: './counter.component.html'
})
export class CounterComponent {
numero: number;
public incrementCounter() {
}
ngOnInit() {
this.numero = 100100100;
}
}
Following directive's TypeScript code:
import { Directive, HostListener, ElementRef, OnInit } from "#angular/core";
#Directive({ selector: "[InputNumber]" })
export class InputNumber implements OnInit, OnChanges {
private el: HTMLInputElement;
constructor(private elementRef: ElementRef) {
this.el = this.elementRef.nativeElement;
}
ngOnInit(): void {
// this.el.value is empty
console.log("Init " + this.el.value);
this.el.value = this.numberWithCommas(this.el.value);
}
ngOnChanges(changes: any): void {
// OnChanging value this code is not executed...
console.log("Change " + this.el.value);
this.el.value = this.numberWithCommas(this.el.value);
}
#HostListener("focus", ["$event.target.value"])
onFocus(value: string) {
this.el.value = this.replaceAll(value, ".", "");
}
#HostListener("blur", ["$event.target.value"])
onBlur(value: string) {
this.el.value = this.numberWithCommas(value);
}
private numberWithCommas(x) {
return x.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ".");
}
private escapeRegExp(str) {
return str.replace(/([.*+?^=!:${}()|\[\]\/\\])/g, "\\$1");
}
private replaceAll(str, find, replace) {
return str.replace(new RegExp(this.escapeRegExp(find), 'g'), replace);
}
}
The following code works except that I need lost focus for show my number like "100.100.100". How can I perform this action on init data loading?
I add one example at this link: Plnkr example
Thanks
You can do this by using a Pipe which takes a boolean parameter that represents your focus/no focus action.
import { Pipe, PipeTransform } from '#angular/core';
#Pipe({name: 'dots'})
export class DotsPipe implements PipeTransform {
transform(value: number, hasFocus:boolean): any {
if(hasFocus){
return value.toString().replace(/\./g,'');
}else{
return value.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ".");
}
}
}
Then you have to apply the Pipe on your [ngModel] and use Angular events (focus) and (focusout) to change your variable.
<input [ngModel]="numero | dots : hasFocus" (focus)="hasFocus=true" (focusout)="hasFocus=false" (ngModelChange)="numero=$event" />
I think that your directive should implement ControlValueAccessor interface https://angular.io/docs/ts/latest/api/forms/index/ControlValueAccessor-interface.html
It is needed for writing model in your directive. ControlValueAccessor interface has writeValue(value: any) method that will be initially called.
So your writeValue method will be something like this:
private onChange: (_: any) => {};
...
writeValue(val) {
const editedValue = this.numberWithCommas(val);
this._onChange(val);
}
registerOnChange(fn: any) : void {
this._onChange = fn;
}

innerHtml doesn't work with ionic 2 pipes, how to?

I have a simple pipe that returns some html
import { Pipe, PipeTransform } from '#angular/core';
#Pipe({
name: 'rating',
pure: false
})
export class RatingPipe implements PipeTransform {
transform(value: any): string {
let stars = "<ion-icon name='star'>" + value + "</ion-icon>";
return stars;
}
}
the problem is when i use it, i get nothing
// this works fine
<p><span innerHtml="{{'<h1>some text</h1>'}}"></span></p>
// if I add a pipe, it doesn't work
<p><span innerHtml="{{variableFromControler | rating}}"></span></p>
// if I add a pipe, it doesn't work
<p><span [innerHtml]="variableFromControler | rating"></span></p>
any ideas?
One solution
import { Pipe, PipeTransform } from '#angular/core';
import { DomSanitizationService } from '#angular/platform-browser'; // to become DomSanitizer
#Pipe({
name: 'rating',
pure: false
})
export class RatingPipe implements PipeTransform {
sanitizer: any;
constructor(private domSanitizationService: DomSanitizationService) {
this.sanitizer = domSanitizationService;
}
transform(value: any): string {
value = parseInt(value);
let stars = '';
for(let i = 1; i <= 5; i++) {
stars += i <= value ? "<ion-icon class='ion-ios-star'></ion-icon>" : "<ion-icon class='ion-ios-star-outline'></ion-icon>";
}
return this.sanitizer.bypassSecurityTrustHtml(stars);
}
}
documentation on DomSanitizationService
It won't work with this html
"<ion-icon name='star'>" + value + "</ion-icon>"
because ion-icon is a ionic-angular component and it should load via angular2 instead of just using innerHTML.
Anyway you should use DomSanitanizeService for your html pipe like this:
#Pipe({
name: 'rating',
pure: false
})
export class RatingPipe implements PipeTransform {
constructor(private domSanitizer: DomSanitizationService){}
transform(value: any): string {
let stars = "<div>" + value + "</div>";
return this.domSanitizer.bypassSecurityTrustHtml(stars);
}
}
And in your html you have to use property binding:
<span [innerHtml]="text | rating"></span>
I would leverage a custom icon wrapper for your case:
#Component({
selector: 'ion-rating-icon',
template: '<ion-icon name="star">{{rating}}</ion-icon>'
})
class RatingIconComponent {
#Input() rating;
}
Then use it like:
<ion-rating-icon [rating]="text"></ion-rating-icon>
See all examples in Plunker

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