lessjs-1.6.1.node_modules.less.lib.less.extend-visitor.js Maven / Gradle / Ivy
(function (tree) {
/*jshint loopfunc:true */
tree.extendFinderVisitor = function() {
this._visitor = new tree.visitor(this);
this.contexts = [];
this.allExtendsStack = [[]];
};
tree.extendFinderVisitor.prototype = {
run: function (root) {
root = this._visitor.visit(root);
root.allExtends = this.allExtendsStack[0];
return root;
},
visitRule: function (ruleNode, visitArgs) {
visitArgs.visitDeeper = false;
},
visitMixinDefinition: function (mixinDefinitionNode, visitArgs) {
visitArgs.visitDeeper = false;
},
visitRuleset: function (rulesetNode, visitArgs) {
if (rulesetNode.root) {
return;
}
var i, j, extend, allSelectorsExtendList = [], extendList;
// get &:extend(.a); rules which apply to all selectors in this ruleset
var rules = rulesetNode.rules, ruleCnt = rules ? rules.length : 0;
for(i = 0; i < ruleCnt; i++) {
if (rulesetNode.rules[i] instanceof tree.Extend) {
allSelectorsExtendList.push(rules[i]);
rulesetNode.extendOnEveryPath = true;
}
}
// now find every selector and apply the extends that apply to all extends
// and the ones which apply to an individual extend
var paths = rulesetNode.paths;
for(i = 0; i < paths.length; i++) {
var selectorPath = paths[i],
selector = selectorPath[selectorPath.length - 1],
selExtendList = selector.extendList;
extendList = selExtendList ? selExtendList.slice(0).concat(allSelectorsExtendList)
: allSelectorsExtendList;
if (extendList) {
extendList = extendList.map(function(allSelectorsExtend) {
return allSelectorsExtend.clone();
});
}
for(j = 0; j < extendList.length; j++) {
this.foundExtends = true;
extend = extendList[j];
extend.findSelfSelectors(selectorPath);
extend.ruleset = rulesetNode;
if (j === 0) { extend.firstExtendOnThisSelectorPath = true; }
this.allExtendsStack[this.allExtendsStack.length-1].push(extend);
}
}
this.contexts.push(rulesetNode.selectors);
},
visitRulesetOut: function (rulesetNode) {
if (!rulesetNode.root) {
this.contexts.length = this.contexts.length - 1;
}
},
visitMedia: function (mediaNode, visitArgs) {
mediaNode.allExtends = [];
this.allExtendsStack.push(mediaNode.allExtends);
},
visitMediaOut: function (mediaNode) {
this.allExtendsStack.length = this.allExtendsStack.length - 1;
},
visitDirective: function (directiveNode, visitArgs) {
directiveNode.allExtends = [];
this.allExtendsStack.push(directiveNode.allExtends);
},
visitDirectiveOut: function (directiveNode) {
this.allExtendsStack.length = this.allExtendsStack.length - 1;
}
};
tree.processExtendsVisitor = function() {
this._visitor = new tree.visitor(this);
};
tree.processExtendsVisitor.prototype = {
run: function(root) {
var extendFinder = new tree.extendFinderVisitor();
extendFinder.run(root);
if (!extendFinder.foundExtends) { return root; }
root.allExtends = root.allExtends.concat(this.doExtendChaining(root.allExtends, root.allExtends));
this.allExtendsStack = [root.allExtends];
return this._visitor.visit(root);
},
doExtendChaining: function (extendsList, extendsListTarget, iterationCount) {
//
// chaining is different from normal extension.. if we extend an extend then we are not just copying, altering and pasting
// the selector we would do normally, but we are also adding an extend with the same target selector
// this means this new extend can then go and alter other extends
//
// this method deals with all the chaining work - without it, extend is flat and doesn't work on other extend selectors
// this is also the most expensive.. and a match on one selector can cause an extension of a selector we had already processed if
// we look at each selector at a time, as is done in visitRuleset
var extendIndex, targetExtendIndex, matches, extendsToAdd = [], newSelector, extendVisitor = this, selectorPath, extend, targetExtend, newExtend;
iterationCount = iterationCount || 0;
//loop through comparing every extend with every target extend.
// a target extend is the one on the ruleset we are looking at copy/edit/pasting in place
// e.g. .a:extend(.b) {} and .b:extend(.c) {} then the first extend extends the second one
// and the second is the target.
// the seperation into two lists allows us to process a subset of chains with a bigger set, as is the
// case when processing media queries
for(extendIndex = 0; extendIndex < extendsList.length; extendIndex++){
for(targetExtendIndex = 0; targetExtendIndex < extendsListTarget.length; targetExtendIndex++){
extend = extendsList[extendIndex];
targetExtend = extendsListTarget[targetExtendIndex];
// look for circular references
if( extend.parent_ids.indexOf( targetExtend.object_id ) >= 0 ){ continue; }
// find a match in the target extends self selector (the bit before :extend)
selectorPath = [targetExtend.selfSelectors[0]];
matches = extendVisitor.findMatch(extend, selectorPath);
if (matches.length) {
// we found a match, so for each self selector..
extend.selfSelectors.forEach(function(selfSelector) {
// process the extend as usual
newSelector = extendVisitor.extendSelector(matches, selectorPath, selfSelector);
// but now we create a new extend from it
newExtend = new(tree.Extend)(targetExtend.selector, targetExtend.option, 0);
newExtend.selfSelectors = newSelector;
// add the extend onto the list of extends for that selector
newSelector[newSelector.length-1].extendList = [newExtend];
// record that we need to add it.
extendsToAdd.push(newExtend);
newExtend.ruleset = targetExtend.ruleset;
//remember its parents for circular references
newExtend.parent_ids = newExtend.parent_ids.concat(targetExtend.parent_ids, extend.parent_ids);
// only process the selector once.. if we have :extend(.a,.b) then multiple
// extends will look at the same selector path, so when extending
// we know that any others will be duplicates in terms of what is added to the css
if (targetExtend.firstExtendOnThisSelectorPath) {
newExtend.firstExtendOnThisSelectorPath = true;
targetExtend.ruleset.paths.push(newSelector);
}
});
}
}
}
if (extendsToAdd.length) {
// try to detect circular references to stop a stack overflow.
// may no longer be needed.
this.extendChainCount++;
if (iterationCount > 100) {
var selectorOne = "{unable to calculate}";
var selectorTwo = "{unable to calculate}";
try
{
selectorOne = extendsToAdd[0].selfSelectors[0].toCSS();
selectorTwo = extendsToAdd[0].selector.toCSS();
}
catch(e) {}
throw {message: "extend circular reference detected. One of the circular extends is currently:"+selectorOne+":extend(" + selectorTwo+")"};
}
// now process the new extends on the existing rules so that we can handle a extending b extending c ectending d extending e...
return extendsToAdd.concat(extendVisitor.doExtendChaining(extendsToAdd, extendsListTarget, iterationCount+1));
} else {
return extendsToAdd;
}
},
visitRule: function (ruleNode, visitArgs) {
visitArgs.visitDeeper = false;
},
visitMixinDefinition: function (mixinDefinitionNode, visitArgs) {
visitArgs.visitDeeper = false;
},
visitSelector: function (selectorNode, visitArgs) {
visitArgs.visitDeeper = false;
},
visitRuleset: function (rulesetNode, visitArgs) {
if (rulesetNode.root) {
return;
}
var matches, pathIndex, extendIndex, allExtends = this.allExtendsStack[this.allExtendsStack.length-1], selectorsToAdd = [], extendVisitor = this, selectorPath;
// look at each selector path in the ruleset, find any extend matches and then copy, find and replace
for(extendIndex = 0; extendIndex < allExtends.length; extendIndex++) {
for(pathIndex = 0; pathIndex < rulesetNode.paths.length; pathIndex++) {
selectorPath = rulesetNode.paths[pathIndex];
// extending extends happens initially, before the main pass
if (rulesetNode.extendOnEveryPath) { continue; }
var extendList = selectorPath[selectorPath.length-1].extendList;
if (extendList && extendList.length) { continue; }
matches = this.findMatch(allExtends[extendIndex], selectorPath);
if (matches.length) {
allExtends[extendIndex].selfSelectors.forEach(function(selfSelector) {
selectorsToAdd.push(extendVisitor.extendSelector(matches, selectorPath, selfSelector));
});
}
}
}
rulesetNode.paths = rulesetNode.paths.concat(selectorsToAdd);
},
findMatch: function (extend, haystackSelectorPath) {
//
// look through the haystack selector path to try and find the needle - extend.selector
// returns an array of selector matches that can then be replaced
//
var haystackSelectorIndex, hackstackSelector, hackstackElementIndex, haystackElement,
targetCombinator, i,
extendVisitor = this,
needleElements = extend.selector.elements,
potentialMatches = [], potentialMatch, matches = [];
// loop through the haystack elements
for(haystackSelectorIndex = 0; haystackSelectorIndex < haystackSelectorPath.length; haystackSelectorIndex++) {
hackstackSelector = haystackSelectorPath[haystackSelectorIndex];
for(hackstackElementIndex = 0; hackstackElementIndex < hackstackSelector.elements.length; hackstackElementIndex++) {
haystackElement = hackstackSelector.elements[hackstackElementIndex];
// if we allow elements before our match we can add a potential match every time. otherwise only at the first element.
if (extend.allowBefore || (haystackSelectorIndex === 0 && hackstackElementIndex === 0)) {
potentialMatches.push({pathIndex: haystackSelectorIndex, index: hackstackElementIndex, matched: 0, initialCombinator: haystackElement.combinator});
}
for(i = 0; i < potentialMatches.length; i++) {
potentialMatch = potentialMatches[i];
// selectors add " " onto the first element. When we use & it joins the selectors together, but if we don't
// then each selector in haystackSelectorPath has a space before it added in the toCSS phase. so we need to work out
// what the resulting combinator will be
targetCombinator = haystackElement.combinator.value;
if (targetCombinator === '' && hackstackElementIndex === 0) {
targetCombinator = ' ';
}
// if we don't match, null our match to indicate failure
if (!extendVisitor.isElementValuesEqual(needleElements[potentialMatch.matched].value, haystackElement.value) ||
(potentialMatch.matched > 0 && needleElements[potentialMatch.matched].combinator.value !== targetCombinator)) {
potentialMatch = null;
} else {
potentialMatch.matched++;
}
// if we are still valid and have finished, test whether we have elements after and whether these are allowed
if (potentialMatch) {
potentialMatch.finished = potentialMatch.matched === needleElements.length;
if (potentialMatch.finished &&
(!extend.allowAfter && (hackstackElementIndex+1 < hackstackSelector.elements.length || haystackSelectorIndex+1 < haystackSelectorPath.length))) {
potentialMatch = null;
}
}
// if null we remove, if not, we are still valid, so either push as a valid match or continue
if (potentialMatch) {
if (potentialMatch.finished) {
potentialMatch.length = needleElements.length;
potentialMatch.endPathIndex = haystackSelectorIndex;
potentialMatch.endPathElementIndex = hackstackElementIndex + 1; // index after end of match
potentialMatches.length = 0; // we don't allow matches to overlap, so start matching again
matches.push(potentialMatch);
}
} else {
potentialMatches.splice(i, 1);
i--;
}
}
}
}
return matches;
},
isElementValuesEqual: function(elementValue1, elementValue2) {
if (typeof elementValue1 === "string" || typeof elementValue2 === "string") {
return elementValue1 === elementValue2;
}
if (elementValue1 instanceof tree.Attribute) {
if (elementValue1.op !== elementValue2.op || elementValue1.key !== elementValue2.key) {
return false;
}
if (!elementValue1.value || !elementValue2.value) {
if (elementValue1.value || elementValue2.value) {
return false;
}
return true;
}
elementValue1 = elementValue1.value.value || elementValue1.value;
elementValue2 = elementValue2.value.value || elementValue2.value;
return elementValue1 === elementValue2;
}
elementValue1 = elementValue1.value;
elementValue2 = elementValue2.value;
if (elementValue1 instanceof tree.Selector) {
if (!(elementValue2 instanceof tree.Selector) || elementValue1.elements.length !== elementValue2.elements.length) {
return false;
}
for(var i = 0; i currentSelectorPathIndex && currentSelectorPathElementIndex > 0) {
path[path.length - 1].elements = path[path.length - 1].elements.concat(selectorPath[currentSelectorPathIndex].elements.slice(currentSelectorPathElementIndex));
currentSelectorPathElementIndex = 0;
currentSelectorPathIndex++;
}
newElements = selector.elements
.slice(currentSelectorPathElementIndex, match.index)
.concat([firstElement])
.concat(replacementSelector.elements.slice(1));
if (currentSelectorPathIndex === match.pathIndex && matchIndex > 0) {
path[path.length - 1].elements =
path[path.length - 1].elements.concat(newElements);
} else {
path = path.concat(selectorPath.slice(currentSelectorPathIndex, match.pathIndex));
path.push(new tree.Selector(
newElements
));
}
currentSelectorPathIndex = match.endPathIndex;
currentSelectorPathElementIndex = match.endPathElementIndex;
if (currentSelectorPathElementIndex >= selectorPath[currentSelectorPathIndex].elements.length) {
currentSelectorPathElementIndex = 0;
currentSelectorPathIndex++;
}
}
if (currentSelectorPathIndex < selectorPath.length && currentSelectorPathElementIndex > 0) {
path[path.length - 1].elements = path[path.length - 1].elements.concat(selectorPath[currentSelectorPathIndex].elements.slice(currentSelectorPathElementIndex));
currentSelectorPathIndex++;
}
path = path.concat(selectorPath.slice(currentSelectorPathIndex, selectorPath.length));
return path;
},
visitRulesetOut: function (rulesetNode) {
},
visitMedia: function (mediaNode, visitArgs) {
var newAllExtends = mediaNode.allExtends.concat(this.allExtendsStack[this.allExtendsStack.length-1]);
newAllExtends = newAllExtends.concat(this.doExtendChaining(newAllExtends, mediaNode.allExtends));
this.allExtendsStack.push(newAllExtends);
},
visitMediaOut: function (mediaNode) {
this.allExtendsStack.length = this.allExtendsStack.length - 1;
},
visitDirective: function (directiveNode, visitArgs) {
var newAllExtends = directiveNode.allExtends.concat(this.allExtendsStack[this.allExtendsStack.length-1]);
newAllExtends = newAllExtends.concat(this.doExtendChaining(newAllExtends, directiveNode.allExtends));
this.allExtendsStack.push(newAllExtends);
},
visitDirectiveOut: function (directiveNode) {
this.allExtendsStack.length = this.allExtendsStack.length - 1;
}
};
})(require('./tree'));
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