partial.js

var _ = require('../util')
var templateParser = require('../parsers/template')
var textParser = require('../parsers/text')
var compiler = require('../compiler')
var Cache = require('../cache')
var cache = new Cache(1000)

// v-partial reuses logic from v-if
var vIf = require('../directives/if')

module.exports = {

  link: vIf.link,
  teardown: vIf.teardown,
  getContainedComponents: vIf.getContainedComponents,

  bind: function () {
    var el = this.el
    this.start = _.createAnchor('v-partial-start')
    this.end = _.createAnchor('v-partial-end')
    _.replace(el, this.end)
    _.before(this.start, this.end)
    var id = el.getAttribute('name')
    var tokens = textParser.parse(id)
    if (tokens) {
      // dynamic partial
      this.setupDynamic(tokens)
    } else {
      // static partial
      this.insert(id)
    }
  },

  setupDynamic: function (tokens) {
    var self = this
    var exp = textParser.tokensToExp(tokens)
    this.unwatch = this.vm.$watch(exp, function (value) {
      self.teardown()
      self.insert(value)
    }, {
      immediate: true,
      user: false
    })
  },

  insert: function (id) {
    var partial = _.resolveAsset(this.vm.$options, 'partials', id)
    if (process.env.NODE_ENV !== 'production') {
      _.assertAsset(partial, 'partial', id)
    }
    if (partial) {
      var frag = templateParser.parse(partial, true)
      // cache partials based on constructor id.
      var cacheId = (this.vm.constructor.cid || '') + partial
      var linker = this.compile(frag, cacheId)
      // this is provided by v-if
      this.link(frag, linker)
    }
  },

  compile: function (frag, cacheId) {
    var hit = cache.get(cacheId)
    if (hit) return hit
    var linker = compiler.compile(frag, this.vm.$options, true)
    cache.put(cacheId, linker)
    return linker
  },

  unbind: function () {
    if (this.unlink) this.unlink()
    if (this.unwatch) this.unwatch()
  }
}