Angular Optimization with Pipe Function

Angular pipe for memoize function execution in the template

This small pipe will improve the performance in the Angular application. Due to memoization and reduced number of computations with pure pipes, You will gain more optimization in Your applications.

Table of Contents

• Installation
• Setup
• Usage

Installation

npm install ngx-pipe-function --save

Setup

Register the NgxPipeFunctionModule in your application NgModule imports.

import { NgxPipeFunctionModule } from 'ngx-pipe-function';

@NgModule({
  imports: [NgxPipeFunctionModule],
})
export class AppModule {}

Usage

Angular executes a pure pipe only when it detects a pure change to the input value. A pure change is either a change to a primitive input value (String, Number, Boolean, Symbol) or a changed object reference (Date, Array, Function, Object).

Syntax

{{ argument | pipeFunction : method [: context] }}

Examples

Just provide argument and executable method to the template with pipeFunction

<div>
    <h3>{{ value | pipeFunction : double }}</h3>
</div>

export class Component {
  public value = 100;

  public double(value: number): number {
    return value * 2;
  }

You could provide multiple arguments for the function like that:

<div>
    <h3>{{ [name, surname] | pipeFunction : compile }}</h3>
</div>

export class Component {
  public name = 'Bob';
  public surname = 'Dylan';

  public compile([name, surname]: string[]): string {
    return btoa(`${name} ${surname}`);
  }

Function with context

We still could have optimization in impure functions with Angular pipes. Just provide context as second parameter to the pipeFunction pipe.

<h3>{{ value | pipeFunction : output : this }}</h3>

Alternative variant use bind

<h3>{{ value | pipeFunction : output.bind(this) }}</h3>

export class Component {
  public value = 'My name is';
  public name = 'Dylan';

  public output(value: string): string {
    return `${value} ${this.name}`;
  }

Note: Also You colud take a look into __tests__ directory for more examples of usage.