<?php
/**
* lessphp v0.4.0
* http://leafo.net/lessphp
*
* LESS css compiler, adapted from http://lesscss.org
*
* Copyright 2012, Leaf Corcoran <leafot@gmail.com>
* Licensed under MIT or GPLv3, see LICENSE
*/
/**
* The less compiler and parser.
*
* Converting LESS to CSS is a three stage process. The incoming file is parsed
* by `lessc_parser` into a syntax tree, then it is compiled into another tree
* representing the CSS structure by `lessc`. The CSS tree is fed into a
* formatter, like `lessc_formatter` which then outputs CSS as a string.
*
* During the first compile, all values are *reduced*, which means that their
* types are brought to the lowest form before being dump as strings. This
* handles math equations, variable dereferences, and the like.
*
* The `parse` function of `lessc` is the entry point.
*
* In summary:
*
* The `lessc` class creates an intstance of the parser, feeds it LESS code,
* then transforms the resulting tree to a CSS tree. This class also holds the
* evaluation context, such as all available mixins and variables at any given
* time.
*
* The `lessc_parser` class is only concerned with parsing its input.
*
* The `lessc_formatter` takes a CSS tree, and dumps it to a formatted string,
* handling things like indentation.
*/
class lessc {
static public $VERSION = "v0.4.0";
static protected $TRUE = array("keyword", "true");
static protected $FALSE = array("keyword", "false");
protected $libFunctions = array();
protected $registeredVars = array();
protected $preserveComments = false;
public $vPrefix = '@'; // prefix of abstract properties
public $mPrefix = '$'; // prefix of abstract blocks
public $parentSelector = '&';
public $importDisabled = false;
public $importDir = '';
protected $numberPrecision = null;
protected $allParsedFiles = array();
// set to the parser that generated the current line when compiling
// so we know how to create error messages
protected $sourceParser = null;
protected $sourceLoc = null;
static public $defaultValue = array("keyword", "");
static protected $nextImportId = 0; // uniquely identify imports
// attempts to find the path of an import url, returns null for css files
protected function findImport($url) {
foreach ((array)$this->importDir as $dir) {
$full = $dir.(substr($dir, -1) != '/' ? '/' : '').$url;
if ($this->fileExists($file = $full.'.less') || $this->fileExists($file = $full)) {
return $file;
}
}
return null;
}
protected function fileExists($name) {
return is_file($name);
}
static public function compressList($items, $delim) {
if (!isset($items[1]) && isset($items[0])) return $items[0];
else return array('list', $delim, $items);
}
static public function preg_quote($what) {
return preg_quote($what, '/');
}
protected function tryImport($importPath, $parentBlock, $out) {
if ($importPath[0] == "function" && $importPath[1] == "url") {
$importPath = $this->flattenList($importPath[2]);
}
$str = $this->coerceString($importPath);
if ($str === null) return false;
$url = $this->compileValue($this->lib_e($str));
// don't import if it ends in css
if (substr_compare($url, '.css', -4, 4) === 0) return false;
$realPath = $this->findImport($url);
if ($realPath === null) return false;
if ($this->importDisabled) {
return array(false, "/* import disabled */");
}
if (isset($this->allParsedFiles[realpath($realPath)])) {
return array(false, null);
}
$this->addParsedFile($realPath);
$parser = $this->makeParser($realPath);
$root = $parser->parse(file_get_contents($realPath));
// set the parents of all the block props
foreach ($root->props as $prop) {
if ($prop[0] == "block") {
$prop[1]->parent = $parentBlock;
}
}
// copy mixins into scope, set their parents
// bring blocks from import into current block
// TODO: need to mark the source parser these came from this file
foreach ($root->children as $childName => $child) {
if (isset($parentBlock->children[$childName])) {
$parentBlock->children[$childName] = array_merge(
$parentBlock->children[$childName],
$child);
} else {
$parentBlock->children[$childName] = $child;
}
}
$pi = pathinfo($realPath);
$dir = $pi["dirname"];
list($top, $bottom) = $this->sortProps($root->props, true);
$this->compileImportedProps($top, $parentBlock, $out, $parser, $dir);
return array(true, $bottom, $parser, $dir);
}
protected function compileImportedProps($props, $block, $out, $sourceParser, $importDir) {
$oldSourceParser = $this->sourceParser;
$oldImport = $this->importDir;
// TODO: this is because the importDir api is stupid
$this->importDir = (array)$this->importDir;
array_unshift($this->importDir, $importDir);
foreach ($props as $prop) {
$this->compileProp($prop, $block, $out);
}
$this->importDir = $oldImport;
$this->sourceParser = $oldSourceParser;
}
/**
* Recursively compiles a block.
*
* A block is analogous to a CSS block in most cases. A single LESS document
* is encapsulated in a block when parsed, but it does not have parent tags
* so all of it's children appear on the root level when compiled.
*
* Blocks are made up of props and children.
*
* Props are property instructions, array tuples which describe an action
* to be taken, eg. write a property, set a variable, mixin a block.
*
* The children of a block are just all the blocks that are defined within.
* This is used to look up mixins when performing a mixin.
*
* Compiling the block involves pushing a fresh environment on the stack,
* and iterating through the props, compiling each one.
*
* See lessc::compileProp()
*
*/
protected function compileBlock($block) {
switch ($block->type) {
case "root":
$this->compileRoot($block);
break;
case null:
$this->compileCSSBlock($block);
break;
case "media":
$this->compileMedia($block);
break;
case "directive":
$name = "@" . $block->name;
if (!empty($block->value)) {
$name .= " " . $this->compileValue($this->reduce($block->value));
}
$this->compileNestedBlock($block, array($name));
break;
default:
$this->throwError("unknown block type: $block->type\n");
}
}
protected function compileCSSBlock($block) {
$env = $this->pushEnv();
$selectors = $this->compileSelectors($block->tags);
$env->selectors = $this->multiplySelectors($selectors);
$out = $this->makeOutputBlock(null, $env->selectors);
$this->scope->children[] = $out;
$this->compileProps($block, $out);
$block->scope = $env; // mixins carry scope with them!
$this->popEnv();
}
protected function compileMedia($media) {
$env = $this->pushEnv($media);
$parentScope = $this->mediaParent($this->scope);
$query = $this->compileMediaQuery($this->multiplyMedia($env));
$this->scope = $this->makeOutputBlock($media->type, array($query));
$parentScope->children[] = $this->scope;
$this->compileProps($media, $this->scope);
if (count($this->scope->lines) > 0) {
$orphanSelelectors = $this->findClosestSelectors();
if (!is_null($orphanSelelectors)) {
$orphan = $this->makeOutputBlock(null, $orphanSelelectors);
$orphan->lines = $this->scope->lines;
array_unshift($this->scope->children, $orphan);
$this->scope->lines = array();
}
}
$this->scope = $this->scope->parent;
$this->popEnv();
}
protected function mediaParent($scope) {
while (!empty($scope->parent)) {
if (!empty($scope->type) && $scope->type != "media") {
break;
}
$scope = $scope->parent;
}
return $scope;
}
protected function compileNestedBlock($block, $selectors) {
$this->pushEnv($block);
$this->scope = $this->makeOutputBlock($block->type, $selectors);
$this->scope->parent->children[] = $this->scope;
$this->compileProps($block, $this->scope);
$this->scope = $this->scope->parent;
$this->popEnv();
}
protected function compileRoot($root) {
$this->pushE