mirror of
https://github.com/ascribe/onion.git
synced 2024-11-15 01:25:17 +01:00
73 lines
1.6 KiB
JavaScript
73 lines
1.6 KiB
JavaScript
'use strict';
|
|
|
|
import Q from 'q';
|
|
|
|
let mapAttr = {
|
|
link: 'href',
|
|
script: 'src'
|
|
};
|
|
|
|
let mapTag = {
|
|
js: 'script',
|
|
css: 'link'
|
|
};
|
|
|
|
function injectTag(tag, src) {
|
|
return Q.Promise((resolve, reject) => {
|
|
if (isPresent(tag, src)) {
|
|
resolve();
|
|
} else {
|
|
let attr = mapAttr[tag];
|
|
let element = document.createElement(tag);
|
|
if (tag === 'script') {
|
|
element.onload = () => resolve();
|
|
element.onerror = () => reject();
|
|
} else {
|
|
resolve();
|
|
}
|
|
document.head.appendChild(element);
|
|
element[attr] = src;
|
|
if (tag === 'link') {
|
|
element.rel = 'stylesheet';
|
|
}
|
|
}
|
|
});
|
|
}
|
|
|
|
function isPresent(tag, src) {
|
|
let attr = mapAttr[tag];
|
|
let query = `head > ${tag}[${attr}="${src}"]`;
|
|
return document.querySelector(query);
|
|
}
|
|
|
|
function injectStylesheet(src) {
|
|
return injectTag('link', src);
|
|
}
|
|
|
|
function injectScript(src) {
|
|
return injectTag('source', src);
|
|
}
|
|
|
|
function inject(src) {
|
|
let ext = src.split('.').pop();
|
|
let tag = mapTag[ext];
|
|
if (!tag) {
|
|
throw new Error(`Cannot inject ${src} in the DOM, cannot guess the tag name from extension "${ext}". Valid extensions are "js" and "css".`);
|
|
}
|
|
|
|
return injectTag(tag, src);
|
|
}
|
|
|
|
export const InjectInHeadUtils = {
|
|
/**
|
|
* Provide functions to inject `<script>` and `<link>` in `<head>`.
|
|
* Useful when you have to load a huge external library and
|
|
* you don't want to embed everything inside the build file.
|
|
*/
|
|
|
|
isPresent,
|
|
injectStylesheet,
|
|
injectScript,
|
|
inject
|
|
};
|