--- /dev/null
+<?php
+
+/**
+ * Process Extends Visitor
+ *
+ * @package Less
+ * @subpackage visitor
+ */
+class Less_Visitor_processExtends extends Less_Visitor{
+
+ public $allExtendsStack;
+
+ /**
+ * @param Less_Tree_Ruleset $root
+ */
+ public function run( $root ){
+ $extendFinder = new Less_Visitor_extendFinder();
+ $extendFinder->run( $root );
+ if( !$extendFinder->foundExtends){
+ return $root;
+ }
+
+ $root->allExtends = $this->doExtendChaining( $root->allExtends, $root->allExtends);
+
+ $this->allExtendsStack = array();
+ $this->allExtendsStack[] = &$root->allExtends;
+
+ return $this->visitObj( $root );
+ }
+
+ private function doExtendChaining( $extendsList, $extendsListTarget, $iterationCount = 0){
+ //
+ // 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
+
+ $extendsToAdd = array();
+
+
+ //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 separation 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, $extendsList_len = count($extendsList); $extendIndex < $extendsList_len; $extendIndex++ ){
+ for( $targetExtendIndex = 0; $targetExtendIndex < count($extendsListTarget); $targetExtendIndex++ ){
+
+ $extend = $extendsList[$extendIndex];
+ $targetExtend = $extendsListTarget[$targetExtendIndex];
+
+ // look for circular references
+ if( in_array($targetExtend->object_id, $extend->parent_ids,true) ){
+ continue;
+ }
+
+ // find a match in the target extends self selector (the bit before :extend)
+ $selectorPath = array( $targetExtend->selfSelectors[0] );
+ $matches = $this->findMatch( $extend, $selectorPath);
+
+
+ if( $matches ){
+
+ // we found a match, so for each self selector..
+ foreach($extend->selfSelectors as $selfSelector ){
+
+
+ // process the extend as usual
+ $newSelector = $this->extendSelector( $matches, $selectorPath, $selfSelector);
+
+ // but now we create a new extend from it
+ $newExtend = new Less_Tree_Extend( $targetExtend->selector, $targetExtend->option, 0);
+ $newExtend->selfSelectors = $newSelector;
+
+ // add the extend onto the list of extends for that selector
+ end($newSelector)->extendList = array($newExtend);
+ //$newSelector[ count($newSelector)-1]->extendList = array($newExtend);
+
+ // record that we need to add it.
+ $extendsToAdd[] = $newExtend;
+ $newExtend->ruleset = $targetExtend->ruleset;
+
+ //remember its parents for circular references
+ $newExtend->parent_ids = array_merge($newExtend->parent_ids,$targetExtend->parent_ids,$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[] = $newSelector;
+ }
+ }
+ }
+ }
+ }
+
+ if( $extendsToAdd ){
+ // try to detect circular references to stop a stack overflow.
+ // may no longer be needed. $this->extendChainCount++;
+ if( $iterationCount > 100) {
+
+ try{
+ $selectorOne = $extendsToAdd[0]->selfSelectors[0]->toCSS();
+ $selectorTwo = $extendsToAdd[0]->selector->toCSS();
+ }catch(Exception $e){
+ $selectorOne = "{unable to calculate}";
+ $selectorTwo = "{unable to calculate}";
+ }
+
+ throw new Less_Exception_Parser("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...
+ $extendsToAdd = $this->doExtendChaining( $extendsToAdd, $extendsListTarget, $iterationCount+1);
+ }
+
+ return array_merge($extendsList, $extendsToAdd);
+ }
+
+
+ protected function visitRule( $ruleNode, &$visitDeeper ){
+ $visitDeeper = false;
+ }
+
+ protected function visitMixinDefinition( $mixinDefinitionNode, &$visitDeeper ){
+ $visitDeeper = false;
+ }
+
+ protected function visitSelector( $selectorNode, &$visitDeeper ){
+ $visitDeeper = false;
+ }
+
+ protected function visitRuleset($rulesetNode){
+
+
+ if( $rulesetNode->root ){
+ return;
+ }
+
+ $allExtends = end($this->allExtendsStack);
+ $paths_len = count($rulesetNode->paths);
+
+ // look at each selector path in the ruleset, find any extend matches and then copy, find and replace
+ foreach($allExtends as $allExtend){
+ for($pathIndex = 0; $pathIndex < $paths_len; $pathIndex++ ){
+
+ // extending extends happens initially, before the main pass
+ if( isset($rulesetNode->extendOnEveryPath) && $rulesetNode->extendOnEveryPath ){
+ continue;
+ }
+
+ $selectorPath = $rulesetNode->paths[$pathIndex];
+
+ if( end($selectorPath)->extendList ){
+ continue;
+ }
+
+ $this->ExtendMatch( $rulesetNode, $allExtend, $selectorPath);
+
+ }
+ }
+ }
+
+
+ private function ExtendMatch( $rulesetNode, $extend, $selectorPath ){
+ $matches = $this->findMatch($extend, $selectorPath);
+
+ if( $matches ){
+ foreach($extend->selfSelectors as $selfSelector ){
+ $rulesetNode->paths[] = $this->extendSelector($matches, $selectorPath, $selfSelector);
+ }
+ }
+ }
+
+
+
+ private function findMatch($extend, $haystackSelectorPath ){
+
+
+ if( !$this->HasMatches($extend, $haystackSelectorPath) ){
+ return false;
+ }
+
+
+ //
+ // 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
+ //
+ $needleElements = $extend->selector->elements;
+ $potentialMatches = array();
+ $potentialMatches_len = 0;
+ $potentialMatch = null;
+ $matches = array();
+
+
+
+ // loop through the haystack elements
+ $haystack_path_len = count($haystackSelectorPath);
+ for($haystackSelectorIndex = 0; $haystackSelectorIndex < $haystack_path_len; $haystackSelectorIndex++ ){
+ $hackstackSelector = $haystackSelectorPath[$haystackSelectorIndex];
+
+ $haystack_elements_len = count($hackstackSelector->elements);
+ for($hackstackElementIndex = 0; $hackstackElementIndex < $haystack_elements_len; $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[] = array('pathIndex'=> $haystackSelectorIndex, 'index'=> $hackstackElementIndex, 'matched'=> 0, 'initialCombinator'=> $haystackElement->combinator);
+ $potentialMatches_len++;
+ }
+
+ for($i = 0; $i < $potentialMatches_len; $i++ ){
+
+ $potentialMatch = &$potentialMatches[$i];
+ $potentialMatch = $this->PotentialMatch( $potentialMatch, $needleElements, $haystackElement, $hackstackElementIndex );
+
+
+ // if we are still valid and have finished, test whether we have elements after and whether these are allowed
+ if( $potentialMatch && $potentialMatch['matched'] === $extend->selector->elements_len ){
+ $potentialMatch['finished'] = true;
+
+ if( !$extend->allowAfter && ($hackstackElementIndex+1 < $haystack_elements_len || $haystackSelectorIndex+1 < $haystack_path_len) ){
+ $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'] = $extend->selector->elements_len;
+ $potentialMatch['endPathIndex'] = $haystackSelectorIndex;
+ $potentialMatch['endPathElementIndex'] = $hackstackElementIndex + 1; // index after end of match
+ $potentialMatches = array(); // we don't allow matches to overlap, so start matching again
+ $potentialMatches_len = 0;
+ $matches[] = $potentialMatch;
+ }
+ continue;
+ }
+
+ array_splice($potentialMatches, $i, 1);
+ $potentialMatches_len--;
+ $i--;
+ }
+ }
+ }
+
+ return $matches;
+ }
+
+
+ // Before going through all the nested loops, lets check to see if a match is possible
+ // Reduces Bootstrap 3.1 compile time from ~6.5s to ~5.6s
+ private function HasMatches($extend, $haystackSelectorPath){
+
+ if( !$extend->selector->cacheable ){
+ return true;
+ }
+
+ $first_el = $extend->selector->_oelements[0];
+
+ foreach($haystackSelectorPath as $hackstackSelector){
+ if( !$hackstackSelector->cacheable ){
+ return true;
+ }
+
+ if( in_array($first_el, $hackstackSelector->_oelements) ){
+ return true;
+ }
+ }
+
+ return false;
+ }
+
+
+ /**
+ * @param integer $hackstackElementIndex
+ */
+ private function PotentialMatch( $potentialMatch, $needleElements, $haystackElement, $hackstackElementIndex ){
+
+
+ if( $potentialMatch['matched'] > 0 ){
+
+ // 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;
+ if( $targetCombinator === '' && $hackstackElementIndex === 0 ){
+ $targetCombinator = ' ';
+ }
+
+ if( $needleElements[ $potentialMatch['matched'] ]->combinator !== $targetCombinator ){
+ return null;
+ }
+ }
+
+ // if we don't match, null our match to indicate failure
+ if( !$this->isElementValuesEqual( $needleElements[$potentialMatch['matched'] ]->value, $haystackElement->value) ){
+ return null;
+ }
+
+ $potentialMatch['finished'] = false;
+ $potentialMatch['matched']++;
+
+ return $potentialMatch;
+ }
+
+
+ private function isElementValuesEqual( $elementValue1, $elementValue2 ){
+
+ if( $elementValue1 === $elementValue2 ){
+ return true;
+ }
+
+ if( is_string($elementValue1) || is_string($elementValue2) ) {
+ return false;
+ }
+
+ if( $elementValue1 instanceof Less_Tree_Attribute ){
+ return $this->isAttributeValuesEqual( $elementValue1, $elementValue2 );
+ }
+
+ $elementValue1 = $elementValue1->value;
+ if( $elementValue1 instanceof Less_Tree_Selector ){
+ return $this->isSelectorValuesEqual( $elementValue1, $elementValue2 );
+ }
+
+ return false;
+ }
+
+
+ /**
+ * @param Less_Tree_Selector $elementValue1
+ */
+ private function isSelectorValuesEqual( $elementValue1, $elementValue2 ){
+
+ $elementValue2 = $elementValue2->value;
+ if( !($elementValue2 instanceof Less_Tree_Selector) || $elementValue1->elements_len !== $elementValue2->elements_len ){
+ return false;
+ }
+
+ for( $i = 0; $i < $elementValue1->elements_len; $i++ ){
+
+ if( $elementValue1->elements[$i]->combinator !== $elementValue2->elements[$i]->combinator ){
+ if( $i !== 0 || ($elementValue1->elements[$i]->combinator || ' ') !== ($elementValue2->elements[$i]->combinator || ' ') ){
+ return false;
+ }
+ }
+
+ if( !$this->isElementValuesEqual($elementValue1->elements[$i]->value, $elementValue2->elements[$i]->value) ){
+ return false;
+ }
+ }
+
+ return true;
+ }
+
+
+ /**
+ * @param Less_Tree_Attribute $elementValue1
+ */
+ private function isAttributeValuesEqual( $elementValue1, $elementValue2 ){
+
+ 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->value : $elementValue1->value );
+ $elementValue2 = ($elementValue2->value->value ? $elementValue2->value->value : $elementValue2->value );
+
+ return $elementValue1 === $elementValue2;
+ }
+
+
+ private function extendSelector($matches, $selectorPath, $replacementSelector){
+
+ //for a set of matches, replace each match with the replacement selector
+
+ $currentSelectorPathIndex = 0;
+ $currentSelectorPathElementIndex = 0;
+ $path = array();
+ $selectorPath_len = count($selectorPath);
+
+ for($matchIndex = 0, $matches_len = count($matches); $matchIndex < $matches_len; $matchIndex++ ){
+
+
+ $match = $matches[$matchIndex];
+ $selector = $selectorPath[ $match['pathIndex'] ];
+
+ $firstElement = new Less_Tree_Element(
+ $match['initialCombinator'],
+ $replacementSelector->elements[0]->value,
+ $replacementSelector->elements[0]->index,
+ $replacementSelector->elements[0]->currentFileInfo
+ );
+
+ if( $match['pathIndex'] > $currentSelectorPathIndex && $currentSelectorPathElementIndex > 0 ){
+ $last_path = end($path);
+ $last_path->elements = array_merge( $last_path->elements, array_slice( $selectorPath[$currentSelectorPathIndex]->elements, $currentSelectorPathElementIndex));
+ $currentSelectorPathElementIndex = 0;
+ $currentSelectorPathIndex++;
+ }
+
+ $newElements = array_merge(
+ array_slice($selector->elements, $currentSelectorPathElementIndex, ($match['index'] - $currentSelectorPathElementIndex) ) // last parameter of array_slice is different than the last parameter of javascript's slice
+ , array($firstElement)
+ , array_slice($replacementSelector->elements,1)
+ );
+
+ if( $currentSelectorPathIndex === $match['pathIndex'] && $matchIndex > 0 ){
+ $last_key = count($path)-1;
+ $path[$last_key]->elements = array_merge($path[$last_key]->elements,$newElements);
+ }else{
+ $path = array_merge( $path, array_slice( $selectorPath, $currentSelectorPathIndex, $match['pathIndex'] ));
+ $path[] = new Less_Tree_Selector( $newElements );
+ }
+
+ $currentSelectorPathIndex = $match['endPathIndex'];
+ $currentSelectorPathElementIndex = $match['endPathElementIndex'];
+ if( $currentSelectorPathElementIndex >= count($selectorPath[$currentSelectorPathIndex]->elements) ){
+ $currentSelectorPathElementIndex = 0;
+ $currentSelectorPathIndex++;
+ }
+ }
+
+ if( $currentSelectorPathIndex < $selectorPath_len && $currentSelectorPathElementIndex > 0 ){
+ $last_path = end($path);
+ $last_path->elements = array_merge( $last_path->elements, array_slice($selectorPath[$currentSelectorPathIndex]->elements, $currentSelectorPathElementIndex));
+ $currentSelectorPathIndex++;
+ }
+
+ $slice_len = $selectorPath_len - $currentSelectorPathIndex;
+ $path = array_merge($path, array_slice($selectorPath, $currentSelectorPathIndex, $slice_len));
+
+ return $path;
+ }
+
+
+ protected function visitMedia( $mediaNode ){
+ $newAllExtends = array_merge( $mediaNode->allExtends, end($this->allExtendsStack) );
+ $this->allExtendsStack[] = $this->doExtendChaining($newAllExtends, $mediaNode->allExtends);
+ }
+
+ protected function visitMediaOut(){
+ array_pop( $this->allExtendsStack );
+ }
+
+ protected function visitDirective( $directiveNode ){
+ $newAllExtends = array_merge( $directiveNode->allExtends, end($this->allExtendsStack) );
+ $this->allExtendsStack[] = $this->doExtendChaining($newAllExtends, $directiveNode->allExtends);
+ }
+
+ protected function visitDirectiveOut(){
+ array_pop($this->allExtendsStack);
+ }
+
+}
\ No newline at end of file
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