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Simple Angular 2+ Prism highlighter module with Rxjs. Click to go to package without Rxjs.


  • Component changeDetection is set to OnPush, it gives better overall performance.
  • Dynamically change highlight string with code input property.
  • Interpolate string to highlight with interpolation object.
  • @ngx-reactive/decorator with rxjs/Subject to Subscribe to code and language property changes.


  • With async true does not work properly.
  • Hooks are defined globally.


If you want to see how @ngx-prism/rxjs works with @angular/cli, get simple example demonstration usage from github repository by opening your command line and do the following:

git clone

Go to file src/app/app.module.ts line 3 comment it, and uncomment line 4.
Go to file src/style.css comment line 2 and uncomment line 3.

npm install && npm start

Open http://localhost:4200/ in your browser.


To install, run:

npm install @ngx-prism/rxjs --save


  1. Import PrismModule into your module.
// example.module.ts
import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';

import { PrismModule } from '@ngx-prism/rxjs';
import { ExampleComponent } from './example.component';

  declarations: [ ExampleComponent ],
  imports: [ CommonModule, PrismModule ],
  exports: [ ExampleComponent ]
export class ExampleModule { }
  1. Use prism component in your example component.
// example.component.ts
import { Component } from '@angular/core';

  selector: 'example-component',
  template: `
    <prism-highlight [language]="language">
export class ExampleComponent {
  language = 'html';
  content = '<p>test</p>';
  constructor() { }

Use PrismComponent by providing code and interpolation property in ExampleComponent.

// example.component.ts
import { Component } from '@angular/core';

  selector: 'example-component',
  template: `
      [language] = "language"
      [hooks] = "hooks"
      [code] = "content"
      [interpolation] = "interpolate"
export class ExampleComponent {
  content = '<p>test {{language}}</p>';
  hooks = {
    'before-sanity-check': (env) => { console.log(`before-sanity-check`, env); },
    'before-highlight': (env) => { console.log(`before-highlight`, env); },
    'after-highlight': (env) => { console.log(`after-highlight`, env); },
    'complete': (env) => { console.log(`complete`, env); },
    'before-insert': (env) => { console.log(`before-insert`, env); }
  interpolate = {
    language: 'language interpolated'
  language = 'html';
  constructor() { }
  • It is possible to import themes files in @angular/cli like below.
@import '~@ngx-prism/rxjs/dist/themes/prism-coy.css';
@import '~@ngx-prism/rxjs/dist/themes/prism-dark.css';
@import '~@ngx-prism/rxjs/dist/themes/prism-funky.css';
@import '~@ngx-prism/rxjs/dist/themes/prism-okaidia.css';
@import '~@ngx-prism/rxjs/dist/themes/prism-solarizedlight.css';
@import '~@ngx-prism/rxjs/dist/themes/prism-tomorrow.css';
@import '~@ngx-prism/rxjs/dist/themes/prism-twilight.css';
@import '~@ngx-prism/rxjs/dist/themes/prism.css';


It is designed to use ng-content and property code separately. You can NOT use both the same time.


name Type Description
async boolean Works only with ng-content. "Whether to use Web Workers to improve performance and avoid blocking the UI when highlighting very large chunks of code." - prismjs
callback (element: Element) => void | undefined = undefined "An optional callback to be invoked after the highlighting is done. Mostly useful when async is true, since in that case, the highlighting is done asynchronously." - prismjs
code string "A string with the code to be highlighted." - prismjs
hooks Object Callback with specific execute time and name: before-sanity-check, before-highlight, after-highlight, complete, before-insert.
interpolation Object | undefined Data property values to inject.
language string "Valid language identifier, for example 'javascript', 'css'." - prismjs

Lifecycle Hooks

Angular Lifecycle Hooks

Performs highlightElement(element, async, callback) prismjs method.

Detect input property code or language changes by comparing currentValue to previousValue.
If yes, set component property change to true.

Unsubscribe Rxjs.Subject subscription in Object property subscription.code and subscription.language.

Initiate subscribes to property code and language with @ngx-reactive/decorator decorator Subscribe().


Clone repository:

git clone

Go to just created folder:

cd rxjs

To build a clean package, means before that script removes node_modules, dist folder and install dependencies:

npm run start:clean

To build a package:

npm start

To run karma tests:

npm test




Semantic Versioning 2.0.0

Given a version number MAJOR.MINOR.PATCH, increment the:
MAJOR version when you make incompatible API changes,
MINOR version when you add functionality in a backwards-compatible manner, and
PATCH version when you make backwards-compatible bug fixes.

Additional labels for pre-release and build metadata are available as extensions to the MAJOR.MINOR.PATCH format.

FAQ How should I deal with revisions in the 0.y.z initial development phase?

The simplest thing to do is start your initial development release at 0.1.0 and then increment the minor version for each subsequent release.

How do I know when to release 1.0.0?

If your software is being used in production, it should probably already be 1.0.0. If you have a stable API on which users have come to depend, you should be 1.0.0. If you’re worrying a lot about backwards compatibility, you should probably already be 1.0.0.


MIT © ngx-prism


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