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4 years ago
"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 = (transformAssetUrlsOptions) => ({
postTransformNode: (node) => {
transform(node, transformAssetUrlsOptions);
}
});
// 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, transformAssetUrlsOptions) {
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, transformAssetUrlsOptions),
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;
}
});
}
}