riot.js

/* Riot v2.2.2, @license MIT, (c) 2015 Muut Inc. + contributors */

;(function(window, undefined) {
  'use strict'
  var riot = { version: 'v2.2.2', settings: {} }

  // This globals 'const' helps code size reduction

  // for typeof == '' comparisons
  var T_STRING = 'string',
      T_OBJECT = 'object',
      T_UNDEF  = 'undefined'

  // for IE8 and rest of the world
  /* istanbul ignore next */
  var isArray = Array.isArray || (function () {
    var _ts = Object.prototype.toString
    return function (v) { return _ts.call(v) === '[object Array]' }
  })()

  // Version# for IE 8-11, 0 for others
  var ieVersion = (function (win) {
    return (window && window.document || {}).documentMode | 0
  })()

riot.observable = function(el) {

  el = el || {}

  var callbacks = {},
      _id = 0

  el.on = function(events, fn) {
    if (isFunction(fn)) {
      if (typeof fn.id === T_UNDEF) fn._id = _id++

      events.replace(/\S+/g, function(name, pos) {
        (callbacks[name] = callbacks[name] || []).push(fn)
        fn.typed = pos > 0
      })
    }
    return el
  }

  el.off = function(events, fn) {
    if (events == '*') callbacks = {}
    else {
      events.replace(/\S+/g, function(name) {
        if (fn) {
          var arr = callbacks[name]
          for (var i = 0, cb; (cb = arr && arr[i]); ++i) {
            if (cb._id == fn._id) arr.splice(i--, 1)
          }
        } else {
          callbacks[name] = []
        }
      })
    }
    return el
  }

  // only single event supported
  el.one = function(name, fn) {
    function on() {
      el.off(name, on)
      fn.apply(el, arguments)
    }
    return el.on(name, on)
  }

  el.trigger = function(name) {
    var args = [].slice.call(arguments, 1),
        fns = callbacks[name] || []

    for (var i = 0, fn; (fn = fns[i]); ++i) {
      if (!fn.busy) {
        fn.busy = 1
        fn.apply(el, fn.typed ? [name].concat(args) : args)
        if (fns[i] !== fn) { i-- }
        fn.busy = 0
      }
    }

    if (callbacks.all && name != 'all') {
      el.trigger.apply(el, ['all', name].concat(args))
    }

    return el
  }

  return el

}
riot.mixin = (function() {
  var mixins = {}

  return function(name, mixin) {
    if (!mixin) return mixins[name]
    mixins[name] = mixin
  }

})()

;(function(riot, evt, win) {

  // browsers only
  if (!win) return

  var loc = win.location,
      fns = riot.observable(),
      started = false,
      current

  function hash() {
    return loc.href.split('#')[1] || ''
  }

  function parser(path) {
    return path.split('/')
  }

  function emit(path) {
    if (path.type) path = hash()

    if (path != current) {
      fns.trigger.apply(null, ['H'].concat(parser(path)))
      current = path
    }
  }

  var r = riot.route = function(arg) {
    // string
    if (arg[0]) {
      loc.hash = arg
      emit(arg)

    // function
    } else {
      fns.on('H', arg)
    }
  }

  r.exec = function(fn) {
    fn.apply(null, parser(hash()))
  }

  r.parser = function(fn) {
    parser = fn
  }

  r.stop = function () {
    if (!started) return
    win.removeEventListener ? win.removeEventListener(evt, emit, false) : win.detachEvent('on' + evt, emit)
    fns.off('*')
    started = false
  }

  r.start = function () {
    if (started) return
    win.addEventListener ? win.addEventListener(evt, emit, false) : win.attachEvent('on' + evt, emit)
    started = true
  }

  // autostart the router
  r.start()

})(riot, 'hashchange', window)
/*

//// How it works?


Three ways:

1. Expressions: tmpl('{ value }', data).
   Returns the result of evaluated expression as a raw object.

2. Templates: tmpl('Hi { name } { surname }', data).
   Returns a string with evaluated expressions.

3. Filters: tmpl('{ show: !done, highlight: active }', data).
   Returns a space separated list of trueish keys (mainly
   used for setting html classes), e.g. "show highlight".


// Template examples

tmpl('{ title || "Untitled" }', data)
tmpl('Results are { results ? "ready" : "loading" }', data)
tmpl('Today is { new Date() }', data)
tmpl('{ message.length > 140 && "Message is too long" }', data)
tmpl('This item got { Math.round(rating) } stars', data)
tmpl('<h1>{ title }</h1>{ body }', data)


// Falsy expressions in templates

In templates (as opposed to single expressions) all falsy values
except zero (undefined/null/false) will default to empty string:

tmpl('{ undefined } - { false } - { null } - { 0 }', {})
// will return: " - - - 0"

*/


var brackets = (function(orig) {

  var cachedBrackets,
      r,
      b,
      re = /[{}]/g

  return function(x) {

    // make sure we use the current setting
    var s = riot.settings.brackets || orig

    // recreate cached vars if needed
    if (cachedBrackets !== s) {
      cachedBrackets = s
      b = s.split(' ')
      r = b.map(function (e) { return e.replace(/(?=.)/g, '\\') })
    }

    // if regexp given, rewrite it with current brackets (only if differ from default)
    return x instanceof RegExp ? (
        s === orig ? x :
        new RegExp(x.source.replace(re, function(b) { return r[~~(b === '}')] }), x.global ? 'g' : '')
      ) :
      // else, get specific bracket
      b[x]
  }
})('{ }')


var tmpl = (function() {

  var cache = {},
      reVars = /(['"\/]).*?[^\\]\1|\.\w*|\w*:|\b(?:(?:new|typeof|in|instanceof) |(?:this|true|false|null|undefined)\b|function *\()|([a-z_$]\w*)/gi
              // [ 1               ][ 2  ][ 3 ][ 4                                                                                  ][ 5       ]
              // find variable names:
              // 1. skip quoted strings and regexps: "a b", 'a b', 'a \'b\'', /a b/
              // 2. skip object properties: .name
              // 3. skip object literals: name:
              // 4. skip javascript keywords
              // 5. match var name

  // build a template (or get it from cache), render with data
  return function(str, data) {
    return str && (cache[str] = cache[str] || tmpl(str))(data)
  }


  // create a template instance

  function tmpl(s, p) {

    // default template string to {}
    s = (s || (brackets(0) + brackets(1)))

      // temporarily convert \{ and \} to a non-character
      .replace(brackets(/\\{/g), '\uFFF0')
      .replace(brackets(/\\}/g), '\uFFF1')

    // split string to expression and non-expresion parts
    p = split(s, extract(s, brackets(/{/), brackets(/}/)))

    return new Function('d', 'return ' + (

      // is it a single expression or a template? i.e. {x} or <b>{x}</b>
      !p[0] && !p[2] && !p[3]

        // if expression, evaluate it
        ? expr(p[1])

        // if template, evaluate all expressions in it
        : '[' + p.map(function(s, i) {

            // is it an expression or a string (every second part is an expression)
          return i % 2

              // evaluate the expressions
              ? expr(s, true)

              // process string parts of the template:
              : '"' + s

                  // preserve new lines
                  .replace(/\n/g, '\\n')

                  // escape quotes
                  .replace(/"/g, '\\"')

                + '"'

        }).join(',') + '].join("")'
      )

      // bring escaped { and } back
      .replace(/\uFFF0/g, brackets(0))
      .replace(/\uFFF1/g, brackets(1))

    + ';')

  }


  // parse { ... } expression

  function expr(s, n) {
    s = s

      // convert new lines to spaces
      .replace(/\n/g, ' ')

      // trim whitespace, brackets, strip comments
      .replace(brackets(/^[{ ]+|[ }]+$|\/\*.+?\*\//g), '')

    // is it an object literal? i.e. { key : value }
    return /^\s*[\w- "']+ *:/.test(s)

      // if object literal, return trueish keys
      // e.g.: { show: isOpen(), done: item.done } -> "show done"
      ? '[' +

          // extract key:val pairs, ignoring any nested objects
          extract(s,

              // name part: name:, "name":, 'name':, name :
              /["' ]*[\w- ]+["' ]*:/,

              // expression part: everything upto a comma followed by a name (see above) or end of line
              /,(?=["' ]*[\w- ]+["' ]*:)|}|$/
              ).map(function(pair) {

                // get key, val parts
                return pair.replace(/^[ "']*(.+?)[ "']*: *(.+?),? *$/, function(_, k, v) {

                  // wrap all conditional parts to ignore errors
                  return v.replace(/[^&|=!><]+/g, wrap) + '?"' + k + '":"",'

                })

              }).join('')

        + '].join(" ").trim()'

      // if js expression, evaluate as javascript
      : wrap(s, n)

  }


  // execute js w/o breaking on errors or undefined vars

  function wrap(s, nonull) {
    s = s.trim()
    return !s ? '' : '(function(v){try{v='

        // prefix vars (name => data.name)
        + (s.replace(reVars, function(s, _, v) { return v ? '(d.'+v+'===undefined?'+(typeof window == 'undefined' ? 'global.' : 'window.')+v+':d.'+v+')' : s })

          // break the expression if its empty (resulting in undefined value)
          || 'x')
      + '}catch(e){'
      + '}finally{return '

        // default to empty string for falsy values except zero
        + (nonull === true ? '!v&&v!==0?"":v' : 'v')

      + '}}).call(d)'
  }


  // split string by an array of substrings

  function split(str, substrings) {
    var parts = []
    substrings.map(function(sub, i) {

      // push matched expression and part before it
      i = str.indexOf(sub)
      parts.push(str.slice(0, i), sub)
      str = str.slice(i + sub.length)
    })

    // push the remaining part
    return parts.concat(str)
  }


  // match strings between opening and closing regexp, skipping any inner/nested matches

  function extract(str, open, close) {

    var start,
        level = 0,
        matches = [],
        re = new RegExp('('+open.source+')|('+close.source+')', 'g')

    str.replace(re, function(_, open, close, pos) {

      // if outer inner bracket, mark position
      if (!level && open) start = pos

      // in(de)crease bracket level
      level += open ? 1 : -1

      // if outer closing bracket, grab the match
      if (!level && close != null) matches.push(str.slice(start, pos+close.length))

    })

    return matches
  }

})()

// { key, i in items} -> { key, i, items }
function loopKeys(expr) {
  var b0 = brackets(0),
      els = expr.slice(b0.length).match(/^\s*(\S+?)\s*(?:,\s*(\S+))?\s+in\s+(.+)$/)
  return els ? { key: els[1], pos: els[2], val: b0 + els[3] } : { val: expr }
}

function mkitem(expr, key, val) {
  var item = {}
  item[expr.key] = key
  if (expr.pos) item[expr.pos] = val
  return item
}


/* Beware: heavy stuff */
function _each(dom, parent, expr) {

  remAttr(dom, 'each')

  var tagName = getTagName(dom),
      template = dom.outerHTML,
      hasImpl = !!tagImpl[tagName],
      impl = tagImpl[tagName] || {
        tmpl: template
      },
      root = dom.parentNode,
      placeholder = document.createComment('riot placeholder'),
      tags = [],
      child = getTag(dom),
      checksum

  root.insertBefore(placeholder, dom)

  expr = loopKeys(expr)

  // clean template code
  parent
    .one('premount', function () {
      if (root.stub) root = parent.root
      // remove the original DOM node
      dom.parentNode.removeChild(dom)
    })
    .on('update', function () {
      var items = tmpl(expr.val, parent)

      // object loop. any changes cause full redraw
      if (!isArray(items)) {

        checksum = items ? JSON.stringify(items) : ''

        items = !items ? [] :
          Object.keys(items).map(function (key) {
            return mkitem(expr, key, items[key])
          })
      }

      var frag = document.createDocumentFragment(),
          i = tags.length,
          j = items.length

      // unmount leftover items
      while (i > j) {
        tags[--i].unmount()
        tags.splice(i, 1)
      }

      for (i = 0; i < j; ++i) {
        var _item = !checksum && !!expr.key ? mkitem(expr, items[i], i) : items[i]

        if (!tags[i]) {
          // mount new
          (tags[i] = new Tag(impl, {
              parent: parent,
              isLoop: true,
              hasImpl: hasImpl,
              root: hasImpl ? dom.cloneNode() : root,
              item: _item
            }, dom.innerHTML)
          ).mount()

          frag.appendChild(tags[i].root)
        } else
          tags[i].update(_item)

        tags[i]._item = _item

      }

      root.insertBefore(frag, placeholder)

      if (child) parent.tags[tagName] = tags

    }).one('updated', function() {
      var keys = Object.keys(parent)// only set new values
      walk(root, function(node) {
        // only set element node and not isLoop
        if (node.nodeType == 1 && !node.isLoop && !node._looped) {
          node._visited = false // reset _visited for loop node
          node._looped = true // avoid set multiple each
          setNamed(node, parent, keys)
        }
      })
    })

}


function parseNamedElements(root, parent, childTags) {

  walk(root, function(dom) {
    if (dom.nodeType == 1) {
      dom.isLoop = dom.isLoop || (dom.parentNode && dom.parentNode.isLoop || dom.getAttribute('each')) ? 1 : 0

      // custom child tag
      var child = getTag(dom)

      if (child && !dom.isLoop) {
        var tag = new Tag(child, { root: dom, parent: parent }, dom.innerHTML),
            tagName = getTagName(dom),
            ptag = parent,
            cachedTag

        while (!getTag(ptag.root)) {
          if (!ptag.parent) break
          ptag = ptag.parent
        }

        // fix for the parent attribute in the looped elements
        tag.parent = ptag

        cachedTag = ptag.tags[tagName]

        // if there are multiple children tags having the same name
        if (cachedTag) {
          // if the parent tags property is not yet an array
          // create it adding the first cached tag
          if (!isArray(cachedTag))
            ptag.tags[tagName] = [cachedTag]
          // add the new nested tag to the array
          ptag.tags[tagName].push(tag)
        } else {
          ptag.tags[tagName] = tag
        }

        // empty the child node once we got its template
        // to avoid that its children get compiled multiple times
        dom.innerHTML = ''
        childTags.push(tag)
      }

      if (!dom.isLoop)
        setNamed(dom, parent, [])
    }

  })

}

function parseExpressions(root, tag, expressions) {

  function addExpr(dom, val, extra) {
    if (val.indexOf(brackets(0)) >= 0) {
      var expr = { dom: dom, expr: val }
      expressions.push(extend(expr, extra))
    }
  }

  walk(root, function(dom) {
    var type = dom.nodeType

    // text node
    if (type == 3 && dom.parentNode.tagName != 'STYLE') addExpr(dom, dom.nodeValue)
    if (type != 1) return

    /* element */

    // loop
    var attr = dom.getAttribute('each')

    if (attr) { _each(dom, tag, attr); return false }

    // attribute expressions
    each(dom.attributes, function(attr) {
      var name = attr.name,
        bool = name.split('__')[1]

      addExpr(dom, attr.value, { attr: bool || name, bool: bool })
      if (bool) { remAttr(dom, name); return false }

    })

    // skip custom tags
    if (getTag(dom)) return false

  })

}
function Tag(impl, conf, innerHTML) {

  var self = riot.observable(this),
      opts = inherit(conf.opts) || {},
      dom = mkdom(impl.tmpl),
      parent = conf.parent,
      isLoop = conf.isLoop,
      hasImpl = conf.hasImpl,
      item = cleanUpData(conf.item),
      expressions = [],
      childTags = [],
      root = conf.root,
      fn = impl.fn,
      tagName = root.tagName.toLowerCase(),
      attr = {},
      propsInSyncWithParent = [],
      loopDom,
      TAG_ATTRIBUTES = /([\w\-]+)\s?=\s?['"]([^'"]+)["']/gim


  if (fn && root._tag) {
    root._tag.unmount(true)
  }

  // not yet mounted
  this.isMounted = false
  root.isLoop = isLoop

  if (impl.attrs) {
    var attrs = impl.attrs.match(TAG_ATTRIBUTES)

    each(attrs, function(a) {
      var kv = a.split(/\s?=\s?/)
      root.setAttribute(kv[0], kv[1].replace(/['"]/g, ''))
    })

  }

  // keep a reference to the tag just created
  // so we will be able to mount this tag multiple times
  root._tag = this

  // create a unique id to this tag
  // it could be handy to use it also to improve the virtual dom rendering speed
  this._id = fastAbs(~~(new Date().getTime() * Math.random()))

  extend(this, { parent: parent, root: root, opts: opts, tags: {} }, item)

  // grab attributes
  each(root.attributes, function(el) {
    var val = el.value
    // remember attributes with expressions only
    if (brackets(/\{.*\}/).test(val)) attr[el.name] = val
  })

  if (dom.innerHTML && !/select|select|optgroup|tbody|tr/.test(tagName))
    // replace all the yield tags with the tag inner html
    dom.innerHTML = replaceYield(dom.innerHTML, innerHTML)

  // options
  function updateOpts() {
    var ctx = hasImpl && isLoop ? self : parent || self
    // update opts from current DOM attributes
    each(root.attributes, function(el) {
      opts[el.name] = tmpl(el.value, ctx)
    })
    // recover those with expressions
    each(Object.keys(attr), function(name) {
      opts[name] = tmpl(attr[name], ctx)
    })
  }

  function normalizeData(data) {
    for (var key in item) {
      if (typeof self[key] !== T_UNDEF)
        self[key] = data[key]
    }
  }

  function inheritFromParent () {
    if (!self.parent || !isLoop) return
    each(Object.keys(self.parent), function(k) {
      // some properties must be always in sync with the parent tag
      var mustSync = ~propsInSyncWithParent.indexOf(k)
      if (typeof self[k] === T_UNDEF || mustSync) {
        // track the property to keep in sync
        // so we can keep it updated
        if (!mustSync) propsInSyncWithParent.push(k)
        self[k] = self.parent[k]
      }
    })
  }

  this.update = function(data) {
    // make sure the data passed will not override
    // the component core methods
    data = cleanUpData(data)
    // inherit properties from the parent
    inheritFromParent()
    // normalize the tag properties in case an item object was initially passed
    if (typeof item === T_OBJECT || isArray(item)) {
      normalizeData(data)
      item = data
    }
    extend(self, data)
    updateOpts()
    self.trigger('update', data)
    update(expressions, self)
    self.trigger('updated')
  }

  this.mixin = function() {
    each(arguments, function(mix) {
      mix = typeof mix === T_STRING ? riot.mixin(mix) : mix
      each(Object.keys(mix), function(key) {
        // bind methods to self
        if (key != 'init')
          self[key] = isFunction(mix[key]) ? mix[key].bind(self) : mix[key]
      })
      // init method will be called automatically
      if (mix.init) mix.init.bind(self)()
    })
  }

  this.mount = function() {

    updateOpts()

    // initialiation
    fn && fn.call(self, opts)

    toggle(true)


    // parse layout after init. fn may calculate args for nested custom tags
    parseExpressions(dom, self, expressions)
    if (!self.parent || hasImpl) parseExpressions(self.root, self, expressions) // top level before update, empty root

    if (!self.parent || isLoop) self.update(item)

    // internal use only, fixes #403
    self.trigger('premount')

    if (isLoop && !hasImpl) {
      // update the root attribute for the looped elements
      self.root = root = loopDom = dom.firstChild

    } else {
      while (dom.firstChild) root.appendChild(dom.firstChild)
      if (root.stub) self.root = root = parent.root
    }
    // if it's not a child tag we can trigger its mount event
    if (!self.parent || self.parent.isMounted) {
      self.isMounted = true
      self.trigger('mount')
    }
    // otherwise we need to wait that the parent event gets triggered
    else self.parent.one('mount', function() {
      // avoid to trigger the `mount` event for the tags
      // not visible included in an if statement
      if (!isInStub(self.root)) {
        self.parent.isMounted = self.isMounted = true
        self.trigger('mount')
      }
    })
  }


  this.unmount = function(keepRootTag) {
    var el = loopDom || root,
        p = el.parentNode

    if (p) {

      if (parent)
        // remove this tag from the parent tags object
        // if there are multiple nested tags with same name..
        // remove this element form the array
        if (isArray(parent.tags[tagName]))
          each(parent.tags[tagName], function(tag, i) {
            if (tag._id == self._id)
              parent.tags[tagName].splice(i, 1)
          })
        else
          // otherwise just delete the tag instance
          parent.tags[tagName] = undefined
      else
        while (el.firstChild) el.removeChild(el.firstChild)

      if (!keepRootTag)
        p.removeChild(el)

    }


    self.trigger('unmount')
    toggle()
    self.off('*')
    // somehow ie8 does not like `delete root._tag`
    root._tag = null

  }

  function toggle(isMount) {

    // mount/unmount children
    each(childTags, function(child) { child[isMount ? 'mount' : 'unmount']() })

    // listen/unlisten parent (events flow one way from parent to children)
    if (parent) {
      var evt = isMount ? 'on' : 'off'

      // the loop tags will be always in sync with the parent automatically
      if (isLoop)
        parent[evt]('unmount', self.unmount)
      else
        parent[evt]('update', self.update)[evt]('unmount', self.unmount)
    }
  }

  // named elements available for fn
  parseNamedElements(dom, this, childTags)


}

function setEventHandler(name, handler, dom, tag) {

  dom[name] = function(e) {

    var item = tag._item,
        ptag = tag.parent

    if (!item)
      while (ptag) {
        item = ptag._item
        ptag = item ? false : ptag.parent
      }

    // cross browser event fix
    e = e || window.event

    // ignore error on some browsers
    try {
      e.currentTarget = dom
      if (!e.target) e.target = e.srcElement
      if (!e.which) e.which = e.charCode || e.keyCode
    } catch (ignored) { '' }

    e.item = item

    // prevent default behaviour (by default)
    if (handler.call(tag, e) !== true && !/radio|check/.test(dom.type)) {
      e.preventDefault && e.preventDefault()
      e.returnValue = false
    }

    if (!e.preventUpdate) {
      var el = item ? tag.parent : tag
      el.update()
    }

  }

}

// used by if- attribute
function insertTo(root, node, before) {
  if (root) {
    root.insertBefore(before, node)
    root.removeChild(node)
  }
}

function update(expressions, tag) {

  each(expressions, function(expr, i) {

    var dom = expr.dom,
        attrName = expr.attr,
        value = tmpl(expr.expr, tag),
        parent = expr.dom.parentNode

    if (value == null) value = ''

    // leave out riot- prefixes from strings inside textarea
    if (parent && parent.tagName == 'TEXTAREA') value = value.replace(/riot-/g, '')

    // no change
    if (expr.value === value) return
    expr.value = value

    // text node
    if (!attrName) return dom.nodeValue = value.toString()

    // remove original attribute
    remAttr(dom, attrName)

    // event handler
    if (isFunction(value)) {
      setEventHandler(attrName, value, dom, tag)

    // if- conditional
    } else if (attrName == 'if') {
      var stub = expr.stub

      // add to DOM
      if (value) {
        if (stub) {
          insertTo(stub.parentNode, stub, dom)
          dom.inStub = false
          // avoid to trigger the mount event if the tags is not visible yet
          // maybe we can optimize this avoiding to mount the tag at all
          if (!isInStub(dom)) {
            walk(dom, function(el) {
              if (el._tag && !el._tag.isMounted) el._tag.isMounted = !!el._tag.trigger('mount')
            })
          }
        }
      // remove from DOM
      } else {
        stub = expr.stub = stub || document.createTextNode('')
        insertTo(dom.parentNode, dom, stub)
        dom.inStub = true
      }
    // show / hide
    } else if (/^(show|hide)$/.test(attrName)) {
      if (attrName == 'hide') value = !value
      dom.style.display = value ? '' : 'none'

    // field value
    } else if (attrName == 'value') {
      dom.value = value

    // <img src="{ expr }">
    } else if (attrName.slice(0, 5) == 'riot-' && attrName != 'riot-tag') {
      attrName = attrName.slice(5)
      value ? dom.setAttribute(attrName, value) : remAttr(dom, attrName)

    } else {
      if (expr.bool) {
        dom[attrName] = value
        if (!value) return
        value = attrName
      }

      if (typeof value !== T_OBJECT) dom.setAttribute(attrName, value)

    }

  })

}

function each(els, fn) {
  for (var i = 0, len = (els || []).length, el; i < len; i++) {
    el = els[i]
    // return false -> remove current item during loop
    if (el != null && fn(el, i) === false) i--
  }
  return els
}

function isFunction(v) {
  return typeof v === 'function' || false   // avoid IE problems
}

function remAttr(dom, name) {
  dom.removeAttribute(name)
}

function fastAbs(nr) {
  return (nr ^ (nr >> 31)) - (nr >> 31)
}

function getTag(dom) {
  var tagName = dom.tagName.toLowerCase()
  return tagImpl[dom.getAttribute(RIOT_TAG) || tagName]
}

function getTagName(dom) {
  var child = getTag(dom),
    namedTag = dom.getAttribute('name'),
    tagName = namedTag && namedTag.indexOf(brackets(0)) < 0 ? namedTag : child ? child.name : dom.tagName.toLowerCase()

  return tagName
}

function extend(src) {
  var obj, args = arguments
  for (var i = 1; i < args.length; ++i) {
    if ((obj = args[i])) {
      for (var key in obj) {      // eslint-disable-line guard-for-in
        src[key] = obj[key]
      }
    }
  }
  return src
}

// with this function we avoid that the current Tag methods get overridden
function cleanUpData(data) {
  if (!(data instanceof Tag)) return data

  var o = {},
      blackList = ['update', 'root', 'mount', 'unmount', 'mixin', 'isMounted', 'isloop', 'tags', 'parent', 'opts']
  for (var key in data) {
    if (!~blackList.indexOf(key))
      o[key] = data[key]
  }
  return o
}

function mkdom(template) {
  var checkie = ieVersion && ieVersion < 10,
      matches = /^\s*<([\w-]+)/.exec(template),
      tagName = matches ? matches[1].toLowerCase() : '',
      rootTag = (tagName === 'th' || tagName === 'td') ? 'tr' :
                (tagName === 'tr' ? 'tbody' : 'div'),
      el = mkEl(rootTag)

  el.stub = true

  if (checkie) {
    if (tagName === 'optgroup')
      optgroupInnerHTML(el, template)
    else if (tagName === 'option')
      optionInnerHTML(el, template)
    else if (rootTag !== 'div')
      tbodyInnerHTML(el, template, tagName)
    else
      checkie = 0
  }
  if (!checkie) el.innerHTML = template

  return el
}

function walk(dom, fn) {
  if (dom) {
    if (fn(dom) === false) walk(dom.nextSibling, fn)
    else {
      dom = dom.firstChild

      while (dom) {
        walk(dom, fn)
        dom = dom.nextSibling
      }
    }
  }
}

function isInStub(dom) {
  while (dom) {
    if (dom.inStub) return true
    dom = dom.parentNode
  }
  return false
}

function mkEl(name) {
  return document.createElement(name)
}

function replaceYield (tmpl, innerHTML) {
  return tmpl.replace(/<(yield)\/?>(<\/\1>)?/gim, innerHTML || '')
}

function $$(selector, ctx) {
  return (ctx || document).querySelectorAll(selector)
}

function $(selector, ctx) {
  return (ctx || document).querySelector(selector)
}

function inherit(parent) {
  function Child() {}
  Child.prototype = parent
  return new Child()
}

function setNamed(dom, parent, keys) {
  each(dom.attributes, function(attr) {
    if (dom._visited) return
    if (attr.name === 'id' || attr.name === 'name') {
      dom._visited = true
      var p, v = attr.value
      if (~keys.indexOf(v)) return

      p = parent[v]
      if (!p)
        parent[v] = dom
      else
        isArray(p) ? p.push(dom) : (parent[v] = [p, dom])
    }
  })
}
/**
 *
 * Hacks needed for the old internet explorer versions [lower than IE10]
 *
 */
/* istanbul ignore next */
function tbodyInnerHTML(el, html, tagName) {
  var div = mkEl('div'),
      loops = /td|th/.test(tagName) ? 3 : 2,
      child

  div.innerHTML = '<table>' + html + '</table>'
  child = div.firstChild

  while (loops--) child = child.firstChild

  el.appendChild(child)

}
/* istanbul ignore next */
function optionInnerHTML(el, html) {
  var opt = mkEl('option'),
      valRegx = /value=[\"'](.+?)[\"']/,
      selRegx = /selected=[\"'](.+?)[\"']/,
      eachRegx = /each=[\"'](.+?)[\"']/,
      ifRegx = /if=[\"'](.+?)[\"']/,
      innerRegx = />([^<]*)</,
      valuesMatch = html.match(valRegx),
      selectedMatch = html.match(selRegx),
      innerValue = html.match(innerRegx),
      eachMatch = html.match(eachRegx),
      ifMatch = html.match(ifRegx)

  if (innerValue) opt.innerHTML = innerValue[1]
  else opt.innerHTML = html

  if (valuesMatch) opt.value = valuesMatch[1]
  if (selectedMatch) opt.setAttribute('riot-selected', selectedMatch[1])
  if (eachMatch) opt.setAttribute('each', eachMatch[1])
  if (ifMatch) opt.setAttribute('if', ifMatch[1])

  el.appendChild(opt)
}
/* istanbul ignore next */
function optgroupInnerHTML(el, html) {
  var opt = mkEl('optgroup'),
      labelRegx = /label=[\"'](.+?)[\"']/,
      elementRegx = /^<([^>]*)>/,
      tagRegx = /^<([^ \>]*)/,
      labelMatch = html.match(labelRegx),
      elementMatch = html.match(elementRegx),
      tagMatch = html.match(tagRegx),
      innerContent = html

  if (elementMatch) {
    var options = html.slice(elementMatch[1].length+2, -tagMatch[1].length-3).trim()
    innerContent = options
  }

  if (labelMatch) opt.setAttribute('riot-label', labelMatch[1])

  if (innerContent) {
    var innerOpt = mkEl('div')

    optionInnerHTML(innerOpt, innerContent)

    opt.appendChild(innerOpt.firstChild)
  }

  el.appendChild(opt)
}

/*
 Virtual dom is an array of custom tags on the document.
 Updates and unmounts propagate downwards from parent to children.
*/

var virtualDom = [],
    tagImpl = {},
    styleNode

var RIOT_TAG = 'riot-tag'

function injectStyle(css) {

  styleNode = styleNode || mkEl('style')

  if (!document.head) return

  if (styleNode.styleSheet)
    styleNode.styleSheet.cssText += css
  else
    styleNode.innerHTML += css

  if (!styleNode._rendered)
    if (styleNode.styleSheet) {
      document.body.appendChild(styleNode)
    } else {
      var rs = $('style[type=riot]')
      if (rs) {
        rs.parentNode.insertBefore(styleNode, rs)
        rs.parentNode.removeChild(rs)
      } else document.head.appendChild(styleNode)

    }

  styleNode._rendered = true

}

function mountTo(root, tagName, opts) {
  var tag = tagImpl[tagName],
      // cache the inner HTML to fix #855
      innerHTML = root._innerHTML = root._innerHTML || root.innerHTML

  // clear the inner html
  root.innerHTML = ''

  if (tag && root) tag = new Tag(tag, { root: root, opts: opts }, innerHTML)

  if (tag && tag.mount) {
    tag.mount()
    virtualDom.push(tag)
    return tag.on('unmount', function() {
      virtualDom.splice(virtualDom.indexOf(tag), 1)
    })
  }

}

riot.tag = function(name, html, css, attrs, fn) {
  if (isFunction(attrs)) {
    fn = attrs
    if (/^[\w\-]+\s?=/.test(css)) {
      attrs = css
      css = ''
    } else attrs = ''
  }
  if (css) {
    if (isFunction(css)) fn = css
    else injectStyle(css)
  }
  tagImpl[name] = { name: name, tmpl: html, attrs: attrs, fn: fn }
  return name
}

riot.mount = function(selector, tagName, opts) {

  var els,
      allTags,
      tags = []

  // helper functions

  function addRiotTags(arr) {
    var list = ''
    each(arr, function (e) {
      list += ', *[riot-tag="'+ e.trim() + '"]'
    })
    return list
  }

  function selectAllTags() {
    var keys = Object.keys(tagImpl)
    return keys + addRiotTags(keys)
  }

  function pushTags(root) {
    if (root.tagName) {
      if (tagName && !root.getAttribute(RIOT_TAG))
        root.setAttribute(RIOT_TAG, tagName)

      var tag = mountTo(root,
        tagName || root.getAttribute(RIOT_TAG) || root.tagName.toLowerCase(), opts)

      if (tag) tags.push(tag)
    }
    else if (root.length) {
      each(root, pushTags)   // assume nodeList
    }
  }

  // ----- mount code -----

  if (typeof tagName === T_OBJECT) {
    opts = tagName
    tagName = 0
  }

  // crawl the DOM to find the tag
  if (typeof selector === T_STRING) {
    if (selector === '*')
      // select all the tags registered
      // and also the tags found with the riot-tag attribute set
      selector = allTags = selectAllTags()
    else
      // or just the ones named like the selector
      selector += addRiotTags(selector.split(','))

    els = $$(selector)
  }
  else
    // probably you have passed already a tag or a NodeList
    els = selector

  // select all the registered and mount them inside their root elements
  if (tagName === '*') {
    // get all custom tags
    tagName = allTags || selectAllTags()
    // if the root els it's just a single tag
    if (els.tagName)
      els = $$(tagName, els)
    else {
      // select all the children for all the different root elements
      var nodeList = []
      each(els, function (_el) {
        nodeList.push($$(tagName, _el))
      })
      els = nodeList
    }
    // get rid of the tagName
    tagName = 0
  }

  if (els.tagName)
    pushTags(els)
  else
    each(els, pushTags)

  return tags
}

// update everything
riot.update = function() {
  return each(virtualDom, function(tag) {
    tag.update()
  })
}

// @deprecated
riot.mountTo = riot.mount


  // share methods for other riot parts, e.g. compiler
  riot.util = { brackets: brackets, tmpl: tmpl }

  // support CommonJS, AMD & browser
  /* istanbul ignore next */
  if (typeof exports === T_OBJECT)
    module.exports = riot
  else if (typeof define === 'function' && define.amd)
    define(function() { return window.riot = riot })
  else
    window.riot = riot

})(typeof window != 'undefined' ? window : undefined);