NG2 SRC FALLBACK

An Angular directive that substitutes the primary image with a fallback should it fail to load.

Features

• Default fallback - If at first you don't succeed, provide a fallback image to [srcFallback] input
• On-The-Fly Fallback creation - If for some reason you don't have an image to set as fallback, check the [customFallbackConfig]

Install

npm i --save ng2-src-fallback

Basic Usage

Add the Ng2SrcFallbackModule module to your module's imports

import {NgModule} from '@angular/core';
import {BrowserModule} from '@angular/platform-browser';
import {AppComponent} from './app.component';
import {Ng2SrcFallbackModule} from 'ng2-src-fallback';
 
@NgModule({
    imports: [
        BrowserModule,
        Ng2SrcFallbackModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent]
})
 
export class AppModule {}

Then add it to your component

import {Component} from '@angular/core';
 
@Component({
  	selector: 'neat-app',
  	template: `
      	<img
      		src="can_of_beans.png"
            ng2-src-fallback
            [srcFallback]="fallbackImgURL">
    `
})
 
export class AppComponent {
  	public fallbackImgURL = 'http://placehold.it/200x200';
}
 

[customFallbackConfig]

Let's say, for some reason, you don't have an image you can use as fallback. Instead of providing a value to the [srcFallback] input, you can use the [customFallbackConfig] to generate 'On-The-Fly' custom placeholder images.

ICustomFallbackConfig

Name	Type	Required	Description
height	String (numeric value and CSS unit)	yes	Height of the generated Image
width	String (numeric value and CSS unit)	yes	Width of the generated Image
bgColour	String	no	Background colour of the generated Image (String)
textSizeAndFont	String (CSS font property syntax)	no	Styling of the Text inside the generated Image
textColour	String	no	Colour of the Text inside the generated Image
textContent	String	no	The text you want to display inside the generated Image
textAlign	CanvasTextAlign	no	The alignment of the text you want to display inside the generated Image
textBaseline	CanvasTextBaseline	no	The Baseline alignment of the text you want to display inside the generated Image
mimeType	String: 'jpeg' | 'png'	no	The mime type of the generated Image

Usage

Add the Ng2SrcFallbackModule module to your module's imports

import {NgModule} from '@angular/core';
import {BrowserModule} from '@angular/platform-browser';
import {AppComponent} from './app';
import {Ng2SrcFallbackModule} from 'ng2-src-fallback';
 
@NgModule({
    imports: [
        BrowserModule,
        Ng2SrcFallbackModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent]
})
 
export class AppModule {}

Then add it to your component and provide a configuration object to the [customFallbackConfig] input

import {Component} from '@angular/core';
import {ICustomFallbackConfig} from 'ng2-src-fallback/custom-fallback-config';
 
@Component({
  	selector: 'neat-app',
  	template: `
      	<img
      		src="can_of_beans.png"
            ng2-src-fallback
            [customFallbackConfig]="customFallbackConfig">
    `
})
 
export class AppComponent {
    public customFallbackConfig: ICustomFallbackConfig = {
        height: '200px',
        width: '200px',
        bgColour: 'black',
        textSizeAndFont: '20px sans-serif',
        textColour: 'white',
        textContent: '200x200',
        textAlign: 'center',
        textBaseline: 'middle',
        mimeType: 'jpeg'
    };
}
 

Events

(wasLoaded)

ng2-src-fallback exposes a (wasLoaded) event that emits when either the src or srcFallback is loaded. To determine whether the original source or the fallback was loaded, add a param to your callback for the (wasLoaded) event.

Example:

First add callback to your component

wasLoaded(isFallback: boolean) {
    // do something based on 'isFallback'
    // or console.log it, don't just take my word
}

and then bind it to the wasLoaded event

<img
    src="a_cat.png"
    ng2-src-fallback
    [srcFallback]="'picture2.png'"
    (wasLoaded)="wasLoaded($event)">

License

MIT © Jaime 'Gondola' Oliveira