complete redesign: use nodejs on server instead of php - documentation to be updated

nodejs/node_modules/stylus/lib/visitor/normalizer.js

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+
+/*!
+ * Stylus - Normalizer
+ * Copyright (c) Automattic <developer.wordpress.com>
+ * MIT Licensed
+ */
+
+/**
+ * Module dependencies.
+ */
+
+var Visitor = require('./')
+  , nodes = require('../nodes')
+  , utils = require('../utils');
+
+/**
+ * Initialize a new `Normalizer` with the given `root` Node.
+ *
+ * This visitor implements the first stage of the duel-stage
+ * compiler, tasked with stripping the "garbage" from
+ * the evaluated nodes, ditching null rules, resolving
+ * ruleset selectors etc. This step performs the logic
+ * necessary to facilitate the "@extend" functionality,
+ * as these must be resolved _before_ buffering output.
+ *
+ * @param {Node} root
+ * @api public
+ */
+
+var Normalizer = module.exports = function Normalizer(root, options) {
+  options = options || {};
+  Visitor.call(this, root);
+  this.hoist = options['hoist atrules'];
+  this.stack = [];
+  this.map = {};
+  this.imports = [];
+};
+
+/**
+ * Inherit from `Visitor.prototype`.
+ */
+
+Normalizer.prototype.__proto__ = Visitor.prototype;
+
+/**
+ * Normalize the node tree.
+ *
+ * @return {Node}
+ * @api private
+ */
+
+Normalizer.prototype.normalize = function(){
+  var ret = this.visit(this.root);
+
+  if (this.hoist) {
+    // hoist @import
+    if (this.imports.length) ret.nodes = this.imports.concat(ret.nodes);
+
+    // hoist @charset
+    if (this.charset) ret.nodes = [this.charset].concat(ret.nodes);
+  }
+
+  return ret;
+};
+
+/**
+ * Bubble up the given `node`.
+ *
+ * @param {Node} node
+ * @api private
+ */
+
+Normalizer.prototype.bubble = function(node){
+  var props = []
+    , other = []
+    , self = this;
+
+  function filterProps(block) {
+    block.nodes.forEach(function(node) {
+      node = self.visit(node);
+
+      switch (node.nodeName) {
+        case 'property':
+          props.push(node);
+          break;
+        case 'block':
+          filterProps(node);
+          break;
+        default:
+          other.push(node);
+      }
+    });
+  }
+
+  filterProps(node.block);
+
+  if (props.length) {
+    var selector = new nodes.Selector([new nodes.Literal('&')]);
+    selector.lineno = node.lineno;
+    selector.column = node.column;
+    selector.filename = node.filename;
+    selector.val = '&';
+
+    var group = new nodes.Group;
+    group.lineno = node.lineno;
+    group.column = node.column;
+    group.filename = node.filename;
+
+    var block = new nodes.Block(node.block, group);
+    block.lineno = node.lineno;
+    block.column = node.column;
+    block.filename = node.filename;
+
+    props.forEach(function(prop){
+      block.push(prop);
+    });
+
+    group.push(selector);
+    group.block = block;
+
+    node.block.nodes = [];
+    node.block.push(group);
+    other.forEach(function(n){
+      node.block.push(n);
+    });
+
+    var group = this.closestGroup(node.block);
+    if (group) node.group = group.clone();
+
+    node.bubbled = true;
+  }
+};
+
+/**
+ * Return group closest to the given `block`.
+ *
+ * @param {Block} block
+ * @return {Group}
+ * @api private
+ */
+
+Normalizer.prototype.closestGroup = function(block){
+  var parent = block.parent
+    , node;
+  while (parent && (node = parent.node)) {
+    if ('group' == node.nodeName) return node;
+    parent = node.block && node.block.parent;
+  }
+};
+
+/**
+ * Visit Root.
+ */
+
+Normalizer.prototype.visitRoot = function(block){
+  var ret = new nodes.Root
+    , node;
+
+  for (var i = 0; i < block.nodes.length; ++i) {
+    node = block.nodes[i];
+    switch (node.nodeName) {
+      case 'null':
+      case 'expression':
+      case 'function':
+      case 'unit':
+      case 'atblock':
+        continue;
+      default:
+        this.rootIndex = i;
+        ret.push(this.visit(node));
+    }
+  }
+
+  return ret;
+};
+
+/**
+ * Visit Property.
+ */
+
+Normalizer.prototype.visitProperty = function(prop){
+  this.visit(prop.expr);
+  return prop;
+};
+
+/**
+ * Visit Expression.
+ */
+
+Normalizer.prototype.visitExpression = function(expr){
+  expr.nodes = expr.nodes.map(function(node){
+    // returns `block` literal if mixin's block
+    // is used as part of a property value
+    if ('block' == node.nodeName) {
+      var literal = new nodes.Literal('block');
+      literal.lineno = expr.lineno;
+      literal.column = expr.column;
+      return literal;
+    }
+    return node;
+  });
+  return expr;
+};
+
+/**
+ * Visit Block.
+ */
+
+Normalizer.prototype.visitBlock = function(block){
+  var node;
+
+  if (block.hasProperties) {
+    for (var i = 0, len = block.nodes.length; i < len; ++i) {
+      node = block.nodes[i];
+      switch (node.nodeName) {
+        case 'null':
+        case 'expression':
+        case 'function':
+        case 'group':
+        case 'unit':
+        case 'atblock':
+          continue;
+        default:
+          block.nodes[i] = this.visit(node);
+      }
+    }
+  }
+
+  // nesting
+  for (var i = 0, len = block.nodes.length; i < len; ++i) {
+    node = block.nodes[i];
+    block.nodes[i] = this.visit(node);
+  }
+
+  return block;
+};
+
+/**
+ * Visit Group.
+ */
+
+Normalizer.prototype.visitGroup = function(group){
+  var stack = this.stack
+    , map = this.map
+    , parts;
+
+  // normalize interpolated selectors with comma
+  group.nodes.forEach(function(selector, i){
+    if (!~selector.val.indexOf(',')) return;
+    if (~selector.val.indexOf('\\,')) {
+      selector.val = selector.val.replace(/\\,/g, ',');
+      return;
+    }
+    parts = selector.val.split(',');
+    var root = '/' == selector.val.charAt(0)
+      , part, s;
+    for (var k = 0, len = parts.length; k < len; ++k){
+      part = parts[k].trim();
+      if (root && k > 0 && !~part.indexOf('&')) {
+        part = '/' + part;
+      }
+      s = new nodes.Selector([new nodes.Literal(part)]);
+      s.val = part;
+      s.block = group.block;
+      group.nodes[i++] = s;
+    }
+  });
+  stack.push(group.nodes);
+
+  var selectors = utils.compileSelectors(stack, true);
+
+  // map for extension lookup
+  selectors.forEach(function(selector){
+    map[selector] = map[selector] || [];
+    map[selector].push(group);
+  });
+
+  // extensions
+  this.extend(group, selectors);
+
+  stack.pop();
+  return group;
+};
+
+/**
+ * Visit Function.
+ */
+
+Normalizer.prototype.visitFunction = function(){
+  return nodes.null;
+};
+
+/**
+ * Visit Media.
+ */
+
+Normalizer.prototype.visitMedia = function(media){
+  var medias = []
+    , group = this.closestGroup(media.block)
+    , parent;
+
+  function mergeQueries(block) {
+    block.nodes.forEach(function(node, i){
+      switch (node.nodeName) {
+        case 'media':
+          node.val = media.val.merge(node.val);
+          medias.push(node);
+          block.nodes[i] = nodes.null;
+          break;
+        case 'block':
+          mergeQueries(node);
+          break;
+        default:
+          if (node.block && node.block.nodes)
+            mergeQueries(node.block);
+      }
+    });
+  }
+
+  mergeQueries(media.block);
+  this.bubble(media);
+
+  if (medias.length) {
+    medias.forEach(function(node){
+      if (group) {
+        group.block.push(node);
+      } else {
+        this.root.nodes.splice(++this.rootIndex, 0, node);
+      }
+      node = this.visit(node);
+      parent = node.block.parent;
+      if (node.bubbled && (!group || 'group' == parent.node.nodeName)) {
+        node.group.block = node.block.nodes[0].block;
+        node.block.nodes[0] = node.group;
+      }
+    }, this);
+  }
+  return media;
+};
+
+/**
+ * Visit Supports.
+ */
+
+Normalizer.prototype.visitSupports = function(node){
+  this.bubble(node);
+  return node;
+};
+
+/**
+ * Visit Atrule.
+ */
+
+Normalizer.prototype.visitAtrule = function(node){
+  if (node.block) node.block = this.visit(node.block);
+  return node;
+};
+
+/**
+ * Visit Keyframes.
+ */
+
+Normalizer.prototype.visitKeyframes = function(node){
+  var frames = node.block.nodes.filter(function(frame){
+    return frame.block && frame.block.hasProperties;
+  });
+  node.frames = frames.length;
+  return node;
+};
+
+/**
+ * Visit Import.
+ */
+
+Normalizer.prototype.visitImport = function(node){
+  this.imports.push(node);
+  return this.hoist ? nodes.null : node;
+};
+
+/**
+ * Visit Charset.
+ */
+
+Normalizer.prototype.visitCharset = function(node){
+  this.charset = node;
+  return this.hoist ? nodes.null : node;
+};
+
+/**
+ * Apply `group` extensions.
+ *
+ * @param {Group} group
+ * @param {Array} selectors
+ * @api private
+ */
+
+Normalizer.prototype.extend = function(group, selectors){
+  var map = this.map
+    , self = this
+    , parent = this.closestGroup(group.block);
+
+  group.extends.forEach(function(extend){
+    var groups = map[extend.selector];
+    if (!groups) {
+      if (extend.optional) return;
+      var err = new Error('Failed to @extend "' + extend.selector + '"');
+      err.lineno = extend.lineno;
+      err.column = extend.column;
+      throw err;
+    }
+    selectors.forEach(function(selector){
+      var node = new nodes.Selector;
+      node.val = selector;
+      node.inherits = false;
+      groups.forEach(function(group){
+        // prevent recursive extend
+        if (!parent || (parent != group)) self.extend(group, selectors);
+        group.push(node);
+      });
+    });
+  });
+
+  group.block = this.visit(group.block);
+};