main

2024年03月18日

柏拉文

越努力，越幸运

一、packages/compiler-dom/src/index.ts compile()

---

export function compile(
  template: string,
  options: CompilerOptions = {}
): CodegenResult {
  return baseCompile(
    template,
    extend({}, parserOptions, options, {
      nodeTransforms: [
        // ignore <script> and <tag>
        // this is not put inside DOMNodeTransforms because that list is used
        // by compiler-ssr to generate vnode fallback branches
        ignoreSideEffectTags,
        ...DOMNodeTransforms,
        ...(options.nodeTransforms || [])
      ],
      directiveTransforms: extend(
        {},
        DOMDirectiveTransforms,
        options.directiveTransforms || {}
      ),
      transformHoist: __BROWSER__ ? null : stringifyStatic
    })
  )
}

二、packages/compiler-core/src/compile.ts baseCompile()

---

// we name it `baseCompile` so that higher order compilers like
// @vue/compiler-dom can export `compile` while re-exporting everything else.
export function baseCompile(
  template: string | RootNode,
  options: CompilerOptions = {}
): CodegenResult {
  const onError = options.onError || defaultOnError
  const isModuleMode = options.mode === 'module'
  /* istanbul ignore if */
  if (__BROWSER__) {
    if (options.prefixIdentifiers === true) {
      onError(createCompilerError(ErrorCodes.X_PREFIX_ID_NOT_SUPPORTED))
    } else if (isModuleMode) {
      onError(createCompilerError(ErrorCodes.X_MODULE_MODE_NOT_SUPPORTED))
    }
  }

  const prefixIdentifiers =
    !__BROWSER__ && (options.prefixIdentifiers === true || isModuleMode)
  if (!prefixIdentifiers && options.cacheHandlers) {
    onError(createCompilerError(ErrorCodes.X_CACHE_HANDLER_NOT_SUPPORTED))
  }
  if (options.scopeId && !isModuleMode) {
    onError(createCompilerError(ErrorCodes.X_SCOPE_ID_NOT_SUPPORTED))
  }

  const ast = isString(template) ? baseParse(template, options) : template
  const [nodeTransforms, directiveTransforms] =
    getBaseTransformPreset(prefixIdentifiers)

  if (!__BROWSER__ && options.isTS) {
    const { expressionPlugins } = options
    if (!expressionPlugins || !expressionPlugins.includes('typescript')) {
      options.expressionPlugins = [...(expressionPlugins || []), 'typescript']
    }
  }

  transform(
    ast,
    extend({}, options, {
      prefixIdentifiers,
      nodeTransforms: [
        ...nodeTransforms,
        ...(options.nodeTransforms || []) // user transforms
      ],
      directiveTransforms: extend(
        {},
        directiveTransforms,
        options.directiveTransforms || {} // user transforms
      )
    })
  )

  return generate(
    ast,
    extend({}, options, {
      prefixIdentifiers
    })
  )
}

三、packages/compiler-core/src/parse.ts baseParse()

---

export function baseParse(
  content: string,
  options: ParserOptions = {}
): RootNode {
  const context = createParserContext(content, options)
  const start = getCursor(context)
  return createRoot(
    parseChildren(context, TextModes.DATA, []),
    getSelection(context, start)
  )
}

四、packages/compiler-core/src/transform.ts transform()

---

export function transform(root: RootNode, options: TransformOptions) {
  const context = createTransformContext(root, options)
  traverseNode(root, context)
  if (options.hoistStatic) {
    hoistStatic(root, context)
  }
  if (!options.ssr) {
    createRootCodegen(root, context)
  }
  // finalize meta information
  root.helpers = new Set([...context.helpers.keys()])
  root.components = [...context.components]
  root.directives = [...context.directives]
  root.imports = context.imports
  root.hoists = context.hoists
  root.temps = context.temps
  root.cached = context.cached

  if (__COMPAT__) {
    root.filters = [...context.filters!]
  }
}

五、packages/compiler-core/src/codegen.ts generate()

---

export function generate(
  ast: RootNode,
  options: CodegenOptions & {
    onContextCreated?: (context: CodegenContext) => void
  } = {}
): CodegenResult {
  const context = createCodegenContext(ast, options)
  if (options.onContextCreated) options.onContextCreated(context)
  const {
    mode,
    push,
    prefixIdentifiers,
    indent,
    deindent,
    newline,
    scopeId,
    ssr
  } = context

  const helpers = Array.from(ast.helpers)
  const hasHelpers = helpers.length > 0
  const useWithBlock = !prefixIdentifiers && mode !== 'module'
  const genScopeId = !__BROWSER__ && scopeId != null && mode === 'module'
  const isSetupInlined = !__BROWSER__ && !!options.inline

  // preambles
  // in setup() inline mode, the preamble is generated in a sub context
  // and returned separately.
  const preambleContext = isSetupInlined
    ? createCodegenContext(ast, options)
    : context
  if (!__BROWSER__ && mode === 'module') {
    genModulePreamble(ast, preambleContext, genScopeId, isSetupInlined)
  } else {
    genFunctionPreamble(ast, preambleContext)
  }
  // enter render function
  const functionName = ssr ? `ssrRender` : `render`
  const args = ssr ? ['_ctx', '_push', '_parent', '_attrs'] : ['_ctx', '_cache']
  if (!__BROWSER__ && options.bindingMetadata && !options.inline) {
    // binding optimization args
    args.push('$props', '$setup', '$data', '$options')
  }
  const signature =
    !__BROWSER__ && options.isTS
      ? args.map(arg => `${arg}: any`).join(',')
      : args.join(', ')

  if (isSetupInlined) {
    push(`(${signature}) => {`)
  } else {
    push(`function ${functionName}(${signature}) {`)
  }
  indent()

  if (useWithBlock) {
    push(`with (_ctx) {`)
    indent()
    // function mode const declarations should be inside with block
    // also they should be renamed to avoid collision with user properties
    if (hasHelpers) {
      push(`const { ${helpers.map(aliasHelper).join(', ')} } = _Vue`)
      push(`\n`)
      newline()
    }
  }

  // generate asset resolution statements
  if (ast.components.length) {
    genAssets(ast.components, 'component', context)
    if (ast.directives.length || ast.temps > 0) {
      newline()
    }
  }
  if (ast.directives.length) {
    genAssets(ast.directives, 'directive', context)
    if (ast.temps > 0) {
      newline()
    }
  }
  if (__COMPAT__ && ast.filters && ast.filters.length) {
    newline()
    genAssets(ast.filters, 'filter', context)
    newline()
  }

  if (ast.temps > 0) {
    push(`let `)
    for (let i = 0; i < ast.temps; i++) {
      push(`${i > 0 ? `, ` : ``}_temp${i}`)
    }
  }
  if (ast.components.length || ast.directives.length || ast.temps) {
    push(`\n`)
    newline()
  }

  // generate the VNode tree expression
  if (!ssr) {
    push(`return `)
  }
  if (ast.codegenNode) {
    genNode(ast.codegenNode, context)
  } else {
    push(`null`)
  }

  if (useWithBlock) {
    deindent()
    push(`}`)
  }

  deindent()
  push(`}`)

  return {
    ast,
    code: context.code,
    preamble: isSetupInlined ? preambleContext.code : ``,
    // SourceMapGenerator does have toJSON() method but it's not in the types
    map: context.map ? (context.map as any).toJSON() : undefined
  }
}