vue/src/compiler/compile.js

var _ = require('../util')
var publicDirectives = require('../directives/public')
var internalDirectives = require('../directives/internal')
var compileProps = require('./compile-props')
var textParser = require('../parsers/text')
var dirParser = require('../parsers/directive')
var templateParser = require('../parsers/template')
var resolveAsset = _.resolveAsset

// special binding prefixes
var bindRE = /^v-bind:|^:/
var onRE = /^v-on:|^@/
var literalRE = /\.literal$/
var argRE = /:(.*)$/
var transitionRE = /^(v-bind:|:)?transition$/

// terminal directives
var terminalDirectives = [
  'for',
  'if'
]

/**
 * Compile a template and return a reusable composite link
 * function, which recursively contains more link functions
 * inside. This top level compile function would normally
 * be called on instance root nodes, but can also be used
 * for partial compilation if the partial argument is true.
 *
 * The returned composite link function, when called, will
 * return an unlink function that tearsdown all directives
 * created during the linking phase.
 *
 * @param {Element|DocumentFragment} el
 * @param {Object} options
 * @param {Boolean} partial
 * @return {Function}
 */

exports.compile = function (el, options, partial) {
  // link function for the node itself.
  var nodeLinkFn = partial || !options._asComponent
    ? compileNode(el, options)
    : null
  // link function for the childNodes
  var childLinkFn =
    !(nodeLinkFn && nodeLinkFn.terminal) &&
    el.tagName !== 'SCRIPT' &&
    el.hasChildNodes()
      ? compileNodeList(el.childNodes, options)
      : null

  /**
   * A composite linker function to be called on a already
   * compiled piece of DOM, which instantiates all directive
   * instances.
   *
   * @param {Vue} vm
   * @param {Element|DocumentFragment} el
   * @param {Vue} [host] - host vm of transcluded content
   * @param {Object} [scope] - v-for scope
   * @param {Fragment} [frag] - link context fragment
   * @return {Function|undefined}
   */

  return function compositeLinkFn (vm, el, host, scope, frag) {
    // cache childNodes before linking parent, fix #657
    var childNodes = _.toArray(el.childNodes)
    // link
    var dirs = linkAndCapture(function compositeLinkCapturer () {
      if (nodeLinkFn) nodeLinkFn(vm, el, host, scope, frag)
      if (childLinkFn) childLinkFn(vm, childNodes, host, scope, frag)
    }, vm)
    return makeUnlinkFn(vm, dirs)
  }
}

/**
 * Apply a linker to a vm/element pair and capture the
 * directives created during the process.
 *
 * @param {Function} linker
 * @param {Vue} vm
 */

function linkAndCapture (linker, vm) {
  var originalDirCount = vm._directives.length
  linker()
  var dirs = vm._directives.slice(originalDirCount)
  dirs.sort(directiveComparator)
  for (var i = 0, l = dirs.length; i < l; i++) {
    dirs[i]._bind()
  }
  return dirs
}

/**
 * Directive priority sort comparator
 *
 * @param {Object} a
 * @param {Object} b
 */

function directiveComparator (a, b) {
  a = a.descriptor.def.priority || 0
  b = b.descriptor.def.priority || 0
  return a > b ? -1 : a === b ? 0 : 1
}

/**
 * Linker functions return an unlink function that
 * tearsdown all directives instances generated during
 * the process.
 *
 * We create unlink functions with only the necessary
 * information to avoid retaining additional closures.
 *
 * @param {Vue} vm
 * @param {Array} dirs
 * @param {Vue} [context]
 * @param {Array} [contextDirs]
 * @return {Function}
 */

function makeUnlinkFn (vm, dirs, context, contextDirs) {
  return function unlink (destroying) {
    teardownDirs(vm, dirs, destroying)
    if (context && contextDirs) {
      teardownDirs(context, contextDirs)
    }
  }
}

/**
 * Teardown partial linked directives.
 *
 * @param {Vue} vm
 * @param {Array} dirs
 * @param {Boolean} destroying
 */

function teardownDirs (vm, dirs, destroying) {
  var i = dirs.length
  while (i--) {
    dirs[i]._teardown()
    if (!destroying) {
      vm._directives.$remove(dirs[i])
    }
  }
}

/**
 * Compile link props on an instance.
 *
 * @param {Vue} vm
 * @param {Element} el
 * @param {Object} props
 * @param {Object} [scope]
 * @return {Function}
 */

exports.compileAndLinkProps = function (vm, el, props, scope) {
  var propsLinkFn = compileProps(el, props)
  var propDirs = linkAndCapture(function () {
    propsLinkFn(vm, scope)
  }, vm)
  return makeUnlinkFn(vm, propDirs)
}

/**
 * Compile the root element of an instance.
 *
 * 1. attrs on context container (context scope)
 * 2. attrs on the component template root node, if
 *    replace:true (child scope)
 *
 * If this is a fragment instance, we only need to compile 1.
 *
 * @param {Vue} vm
 * @param {Element} el
 * @param {Object} options
 * @return {Function}
 */

exports.compileRoot = function (el, options) {
  var containerAttrs = options._containerAttrs
  var replacerAttrs = options._replacerAttrs
  var contextLinkFn, replacerLinkFn

  // only need to compile other attributes for
  // non-fragment instances
  if (el.nodeType !== 11) {
    // for components, container and replacer need to be
    // compiled separately and linked in different scopes.
    if (options._asComponent) {
      // 2. container attributes
      if (containerAttrs) {
        contextLinkFn = compileDirectives(containerAttrs, options)
      }
      if (replacerAttrs) {
        // 3. replacer attributes
        replacerLinkFn = compileDirectives(replacerAttrs, options)
      }
    } else {
      // non-component, just compile as a normal element.
      replacerLinkFn = compileDirectives(el.attributes, options)
    }
  }

  return function rootLinkFn (vm, el, scope) {
    // link context scope dirs
    var context = vm._context
    var contextDirs
    if (context && contextLinkFn) {
      contextDirs = linkAndCapture(function () {
        contextLinkFn(context, el, null, scope)
      }, context)
    }

    // link self
    var selfDirs = linkAndCapture(function () {
      if (replacerLinkFn) replacerLinkFn(vm, el)
    }, vm)

    // return the unlink function that tearsdown context
    // container directives.
    return makeUnlinkFn(vm, selfDirs, context, contextDirs)
  }
}

/**
 * Compile a node and return a nodeLinkFn based on the
 * node type.
 *
 * @param {Node} node
 * @param {Object} options
 * @return {Function|null}
 */

function compileNode (node, options) {
  var type = node.nodeType
  if (type === 1 && node.tagName !== 'SCRIPT') {
    return compileElement(node, options)
  } else if (type === 3 && node.data.trim()) {
    return compileTextNode(node, options)
  } else {
    return null
  }
}

/**
 * Compile an element and return a nodeLinkFn.
 *
 * @param {Element} el
 * @param {Object} options
 * @return {Function|null}
 */

function compileElement (el, options) {
  // preprocess textareas.
  // textarea treats its text content as the initial value.
  // just bind it as an attr directive for value.
  if (el.tagName === 'TEXTAREA') {
    var tokens = textParser.parse(el.value)
    if (tokens) {
      el.setAttribute(':value', textParser.tokensToExp(tokens))
      el.value = ''
    }
  }
  var linkFn
  var hasAttrs = el.hasAttributes()
  // check terminal directives (for & if)
  if (hasAttrs) {
    linkFn = checkTerminalDirectives(el, options)
  }
  // check element directives
  if (!linkFn) {
    linkFn = checkElementDirectives(el, options)
  }
  // check component
  if (!linkFn) {
    linkFn = checkComponent(el, options)
  }
  // normal directives
  if (!linkFn && hasAttrs) {
    linkFn = compileDirectives(el.attributes, options)
  }
  return linkFn
}

/**
 * Compile a textNode and return a nodeLinkFn.
 *
 * @param {TextNode} node
 * @param {Object} options
 * @return {Function|null} textNodeLinkFn
 */

function compileTextNode (node, options) {
  var tokens = textParser.parse(node.data)
  if (!tokens) {
    return null
  }
  var frag = document.createDocumentFragment()
  var el, token
  for (var i = 0, l = tokens.length; i < l; i++) {
    token = tokens[i]
    el = token.tag
      ? processTextToken(token, options)
      : document.createTextNode(token.value)
    frag.appendChild(el)
  }
  return makeTextNodeLinkFn(tokens, frag, options)
}

/**
 * Process a single text token.
 *
 * @param {Object} token
 * @param {Object} options
 * @return {Node}
 */

function processTextToken (token, options) {
  var el
  if (token.oneTime) {
    el = document.createTextNode(token.value)
  } else {
    if (token.html) {
      el = document.createComment('v-html')
      setTokenType('html')
    } else {
      // IE will clean up empty textNodes during
      // frag.cloneNode(true), so we have to give it
      // something here...
      el = document.createTextNode(' ')
      setTokenType('text')
    }
  }
  function setTokenType (type) {
    if (token.descriptor) return
    var parsed = dirParser.parse(token.value)
    token.descriptor = {
      name: type,
      def: publicDirectives[type],
      expression: parsed.expression,
      filters: parsed.filters
    }
  }
  return el
}

/**
 * Build a function that processes a textNode.
 *
 * @param {Array<Object>} tokens
 * @param {DocumentFragment} frag
 */

function makeTextNodeLinkFn (tokens, frag) {
  return function textNodeLinkFn (vm, el, host, scope) {
    var fragClone = frag.cloneNode(true)
    var childNodes = _.toArray(fragClone.childNodes)
    var token, value, node
    for (var i = 0, l = tokens.length; i < l; i++) {
      token = tokens[i]
      value = token.value
      if (token.tag) {
        node = childNodes[i]
        if (token.oneTime) {
          value = (scope || vm).$eval(value)
          if (token.html) {
            _.replace(node, templateParser.parse(value, true))
          } else {
            node.data = value
          }
        } else {
          vm._bindDir(token.descriptor, node, host, scope)
        }
      }
    }
    _.replace(el, fragClone)
  }
}

/**
 * Compile a node list and return a childLinkFn.
 *
 * @param {NodeList} nodeList
 * @param {Object} options
 * @return {Function|undefined}
 */

function compileNodeList (nodeList, options) {
  var linkFns = []
  var nodeLinkFn, childLinkFn, node
  for (var i = 0, l = nodeList.length; i < l; i++) {
    node = nodeList[i]
    nodeLinkFn = compileNode(node, options)
    childLinkFn =
      !(nodeLinkFn && nodeLinkFn.terminal) &&
      node.tagName !== 'SCRIPT' &&
      node.hasChildNodes()
        ? compileNodeList(node.childNodes, options)
        : null
    linkFns.push(nodeLinkFn, childLinkFn)
  }
  return linkFns.length
    ? makeChildLinkFn(linkFns)
    : null
}

/**
 * Make a child link function for a node's childNodes.
 *
 * @param {Array<Function>} linkFns
 * @return {Function} childLinkFn
 */

function makeChildLinkFn (linkFns) {
  return function childLinkFn (vm, nodes, host, scope, frag) {
    var node, nodeLinkFn, childrenLinkFn
    for (var i = 0, n = 0, l = linkFns.length; i < l; n++) {
      node = nodes[n]
      nodeLinkFn = linkFns[i++]
      childrenLinkFn = linkFns[i++]
      // cache childNodes before linking parent, fix #657
      var childNodes = _.toArray(node.childNodes)
      if (nodeLinkFn) {
        nodeLinkFn(vm, node, host, scope, frag)
      }
      if (childrenLinkFn) {
        childrenLinkFn(vm, childNodes, host, scope, frag)
      }
    }
  }
}

/**
 * Check for element directives (custom elements that should
 * be resovled as terminal directives).
 *
 * @param {Element} el
 * @param {Object} options
 */

function checkElementDirectives (el, options) {
  var tag = el.tagName.toLowerCase()
  if (_.commonTagRE.test(tag)) return
  var def = resolveAsset(options, 'elementDirectives', tag)
  if (def) {
    return makeTerminalNodeLinkFn(el, tag, '', options, def)
  }
}

/**
 * Check if an element is a component. If yes, return
 * a component link function.
 *
 * @param {Element} el
 * @param {Object} options
 * @return {Function|undefined}
 */

function checkComponent (el, options) {
  var component = _.checkComponent(el, options)
  if (component) {
    var descriptor = {
      name: 'component',
      expression: component.id,
      literal: !component.dynamic,
      def: internalDirectives.component
    }
    var componentLinkFn = function (vm, el, host, scope, frag) {
      vm._bindDir(descriptor, el, host, scope, frag)
    }
    componentLinkFn.terminal = true
    return componentLinkFn
  }
}

/**
 * Check an element for terminal directives in fixed order.
 * If it finds one, return a terminal link function.
 *
 * @param {Element} el
 * @param {Object} options
 * @return {Function} terminalLinkFn
 */

function checkTerminalDirectives (el, options) {
  // skip v-pre
  if (_.attr(el, 'v-pre') !== null) {
    return skip
  }
  // skip v-else block, but only if following v-if
  if (el.hasAttribute('v-else')) {
    var prev = el.previousElementSibling
    if (prev && prev.hasAttribute('v-if')) {
      return skip
    }
  }
  var value, dirName
  for (var i = 0, l = terminalDirectives.length; i < l; i++) {
    dirName = terminalDirectives[i]
    /* eslint-disable no-cond-assign */
    if (value = el.getAttribute('v-' + dirName)) {
      return makeTerminalNodeLinkFn(el, dirName, value, options)
    }
    /* eslint-enable no-cond-assign */
  }
}

function skip () {}
skip.terminal = true

/**
 * Build a node link function for a terminal directive.
 * A terminal link function terminates the current
 * compilation recursion and handles compilation of the
 * subtree in the directive.
 *
 * @param {Element} el
 * @param {String} dirName
 * @param {String} value
 * @param {Object} options
 * @param {Object} [def]
 * @return {Function} terminalLinkFn
 */

function makeTerminalNodeLinkFn (el, dirName, value, options, def) {
  var parsed = dirParser.parse(value)
  var descriptor = {
    name: dirName,
    expression: parsed.expression,
    filters: parsed.filters,
    // either an element directive, or if/for
    def: def || publicDirectives[dirName]
  }
  var fn = function terminalNodeLinkFn (vm, el, host, scope, frag) {
    vm._bindDir(descriptor, el, host, scope, frag)
  }
  fn.terminal = true
  return fn
}

/**
 * Compile the directives on an element and return a linker.
 *
 * @param {Array|NamedNodeMap} attrs
 * @param {Object} options
 * @return {Function}
 */

function compileDirectives (attrs, options) {
  var i = attrs.length
  var dirs = []
  var attr, name, value, dirName, arg, dirDef, isLiteral
  while (i--) {
    attr = attrs[i]
    name = attr.name
    value = attr.value

    // special attribute: transition
    if (transitionRE.test(name)) {
      pushDir('transition', internalDirectives.transition, {
        literal: !bindRE.test(name)
      })
    } else

    // event handlers
    if (onRE.test(name)) {
      pushDir('on', publicDirectives.on, {
        arg: name.replace(onRE, '')
      })
    } else

    // attribute bindings
    if (bindRE.test(name)) {
      dirName = name.replace(bindRE, '')
      if (dirName === 'style' || dirName === 'class') {
        pushDir(dirName, internalDirectives[dirName])
      } else {
        pushDir('bind', publicDirectives.bind, {
          arg: dirName
        })
      }
    } else

    // normal directives
    if (name.indexOf('v-') === 0) {
      // check literal
      isLiteral = literalRE.test(name)
      if (isLiteral) {
        name = name.replace(literalRE, '')
      }
      // check arg
      arg = (arg = name.match(argRE)) && arg[1]
      if (arg) {
        name = name.replace(argRE, '')
      }
      // extract directive name
      dirName = name.slice(2)

      // skip v-else (when used with v-show)
      if (dirName === 'else') {
        continue
      }

      dirDef = resolveAsset(options, 'directives', dirName)

      if (process.env.NODE_ENV !== 'production') {
        _.assertAsset(dirDef, 'directive', dirName)
      }

      if (dirDef) {
        if (!isLiteral && _.isLiteral(value)) {
          value = _.stripQuotes(value)
          isLiteral = true
        }
        pushDir(dirName, dirDef, {
          arg: arg,
          literal: isLiteral
        })
      }
    }
  }

  /**
   * Push a directive.
   *
   * @param {String} dirName
   * @param {Object|Function} def
   * @param {Object} [opts]
   */

  function pushDir (dirName, def, opts) {
    var parsed = dirParser.parse(value)
    var dir = {
      name: dirName,
      attr: name,
      raw: value,
      def: def,
      expression: parsed.expression,
      filters: parsed.filters
    }
    if (opts) {
      _.extend(dir, opts)
    }
    dirs.push(dir)
  }

  if (dirs.length) {
    return makeNodeLinkFn(dirs)
  }
}

/**
 * Build a link function for all directives on a single node.
 *
 * @param {Array} directives
 * @return {Function} directivesLinkFn
 */

function makeNodeLinkFn (directives) {
  return function nodeLinkFn (vm, el, host, scope, frag) {
    // reverse apply because it's sorted low to high
    var i = directives.length
    while (i--) {
      vm._bindDir(directives[i], el, host, scope, frag)
    }
  }
}