chushihua

2026-01-26 23:20:48 +08:00
commit 7b5aab0206
22521 changed files with 3300090 additions and 0 deletions
@@ -0,0 +1,47 @@
+// vue compiler module for transforming `img:srcset` to a number of `require`s
+
+const urlToRequire = require('../url-to-require')
+
+module.exports = () => ({
+  postTransformNode: node => {
+    transform(node)
+  }
+})
+
+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
+        }
+
+        // http://w3c.github.io/html/semantics-embedded-content.html#ref-for-image-candidate-string-5
+        const escapedSpaceCharacters = /( |\\t|\\n|\\f|\\r)+/g
+
+        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: urlToRequire(url), descriptor: 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
+      }
+    })
+  }
+}