transform() — vue Function Reference

Architecture documentation for the transform() function in srcset.ts from the vue codebase.

Function typescript SfcCompiler ScriptCompiler calls 2

Entity Profile

SfcCompiler→ ScriptCompiler→ transform() — vue Function Reference

Dependency Diagram

graph TD
  7517df93_2b97_cb05_d1cf_00c25c305369["transform()"]
  d1a7581d_37f4_760f_46fe_99640069e5dd["srcset.ts"]
  7517df93_2b97_cb05_d1cf_00c25c305369 -->|defined in| d1a7581d_37f4_760f_46fe_99640069e5dd
  d351a240_af5e_b0a1_a277_fa541902c2e7["transform()"]
  7517df93_2b97_cb05_d1cf_00c25c305369 -->|calls| d351a240_af5e_b0a1_a277_fa541902c2e7
  8fd1d7ae_4758_a029_20c6_a5380f519c70["urlToRequire()"]
  7517df93_2b97_cb05_d1cf_00c25c305369 -->|calls| 8fd1d7ae_4758_a029_20c6_a5380f519c70
  style 7517df93_2b97_cb05_d1cf_00c25c305369 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

packages/compiler-sfc/src/templateCompilerModules/srcset.ts lines 21–76

function transform(
  node: ASTNode,
  transformAssetUrlsOptions?: TransformAssetUrlsOptions
) {
  if (node.type !== 1 || !node.attrs) {
    return
  }

  if (node.tag === 'img' || node.tag === 'source') {
    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: ImageCandidate[] = value
          .slice(1, -1)
          .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, 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
      }
    })
  }
}