52 lines
2.1 KiB
JavaScript
52 lines
2.1 KiB
JavaScript
|
"use strict";
|
||
|
|
// vue compiler module for transforming `img:srcset` to a number of `require`s
|
||
|
|
Object.defineProperty(exports, "__esModule", { value: true });
|
||
|
|
const utils_1 = require("./utils");
|
||
|
|
exports.default = () => ({
|
||
|
|
postTransformNode: (node) => {
|
||
|
|
transform(node);
|
||
|
|
}
|
||
|
|
});
|
||
|
|
// http://w3c.github.io/html/semantics-embedded-content.html#ref-for-image-candidate-string-5
|
||
|
|
const escapedSpaceCharacters = /( |\\t|\\n|\\f|\\r)+/g;
|
||
|
|
function transform(node) {
|
||
|
|
const tags = ['img', 'source'];
|
||
|
|
if (tags.indexOf(node.tag) !== -1 && node.attrs) {
|
||
|
|
node.attrs.forEach(attr => {
|
||
|
|
if (attr.name === 'srcset') {
|
||
|
|
// same logic as in transform-require.js
|
||
|
|
const value = attr.value;
|
||
|
|
const isStatic = value.charAt(0) === '"' && value.charAt(value.length - 1) === '"';
|
||
|
|
if (!isStatic) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
const imageCandidates = value
|
||
|
|
.substr(1, value.length - 2)
|
||
|
|
.split(',')
|
||
|
|
.map(s => {
|
||
|
|
// The attribute value arrives here with all whitespace, except
|
||
|
|
// normal spaces, represented by escape sequences
|
||
|
|
const [url, descriptor] = s
|
||
|
|
.replace(escapedSpaceCharacters, ' ')
|
||
|
|
.trim()
|
||
|
|
.split(' ', 2);
|
||
|
|
return { require: utils_1.urlToRequire(url), descriptor };
|
||
|
|
});
|
||
|
|
// "require(url1)"
|
||
|
|
// "require(url1) 1x"
|
||
|
|
// "require(url1), require(url2)"
|
||
|
|
// "require(url1), require(url2) 2x"
|
||
|
|
// "require(url1) 1x, require(url2)"
|
||
|
|
// "require(url1) 1x, require(url2) 2x"
|
||
|
|
const code = imageCandidates
|
||
|
|
.map(({ require, descriptor }) => `${require} + "${descriptor ? ' ' + descriptor : ''}, " + `)
|
||
|
|
.join('')
|
||
|
|
.slice(0, -6)
|
||
|
|
.concat('"')
|
||
|
|
.replace(/ \+ ""$/, '');
|
||
|
|
attr.value = code;
|
||
|
|
}
|
||
|
|
});
|
||
|
|
}
|
||
|
|
}
|