Files
dspace-angular/src/app/thumbnail/thumbnail.component.ts
2020-02-17 18:35:10 +01:00

62 lines
2.6 KiB
TypeScript

import { Component, Input, OnInit } from '@angular/core';
import { Bitstream } from '../core/shared/bitstream.model';
import { hasValue } from '../shared/empty.util';
/**
* A fallback placeholder image as a base64 string
*/
const placeholder = 'data:image/svg+xml;charset=UTF-8,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20width%3D%2293%22%20height%3D%22120%22%20viewBox%3D%220%200%2093%20120%22%20preserveAspectRatio%3D%22none%22%3E%3C!--%0ASource%20URL%3A%20holder.js%2F93x120%3Ftext%3DNo%20Thumbnail%0ACreated%20with%20Holder.js%202.8.2.%0ALearn%20more%20at%20http%3A%2F%2Fholderjs.com%0A(c)%202012-2015%20Ivan%20Malopinsky%20-%20http%3A%2F%2Fimsky.co%0A--%3E%3Cdefs%3E%3Cstyle%20type%3D%22text%2Fcss%22%3E%3C!%5BCDATA%5B%23holder_1543e460b05%20text%20%7B%20fill%3A%23AAAAAA%3Bfont-weight%3Abold%3Bfont-family%3AArial%2C%20Helvetica%2C%20Open%20Sans%2C%20sans-serif%2C%20monospace%3Bfont-size%3A10pt%20%7D%20%5D%5D%3E%3C%2Fstyle%3E%3C%2Fdefs%3E%3Cg%20id%3D%22holder_1543e460b05%22%3E%3Crect%20width%3D%2293%22%20height%3D%22120%22%20fill%3D%22%23FFFFFF%22%2F%3E%3Cg%3E%3Ctext%20x%3D%2235.6171875%22%20y%3D%2257%22%3ENo%3C%2Ftext%3E%3Ctext%20x%3D%2210.8125%22%20y%3D%2272%22%3EThumbnail%3C%2Ftext%3E%3C%2Fg%3E%3C%2Fg%3E%3C%2Fsvg%3E';
/**
* This component renders a given Bitstream as a thumbnail.
* One input parameter of type Bitstream is expected.
* If no Bitstream is provided, a holderjs image will be rendered instead.
*/
@Component({
selector: 'ds-thumbnail',
styleUrls: ['./thumbnail.component.scss'],
templateUrl: './thumbnail.component.html'
})
export class ThumbnailComponent implements OnInit {
/**
* The thumbnail Bitstream
*/
@Input() thumbnail: Bitstream;
/**
* The default image, used if the thumbnail isn't set or can't be downloaded
*/
@Input() defaultImage? = placeholder;
/**
* The src attribute used in the template to render the image.
*/
src: string;
/**
* Initialize the thumbnail.
* Use a default image if no actual image is available.
*/
ngOnInit(): void {
if (hasValue(this.thumbnail) && hasValue(this.thumbnail._links) && hasValue(this.thumbnail._links.content) && this.thumbnail._links.content.href) {
this.src = this.thumbnail._links.content.href;
} else {
this.src = this.defaultImage
}
}
/**
* Handle image download errors.
* If the image can't be found, use the defaultImage instead.
* If that also can't be found, use the base64 placeholder.
*/
errorHandler(event) {
if (event.currentTarget.src !== this.defaultImage) {
event.currentTarget.src = this.defaultImage;
} else {
event.currentTarget.src = placeholder;
}
}
}