PHP CSS Parser
--------------
[](https://travis-ci.org/sabberworm/PHP-CSS-Parser) [](http://hhvm.h4cc.de/package/sabberworm/php-css-parser)
A Parser for CSS Files written in PHP. Allows extraction of CSS files into a data structure, manipulation of said structure and output as (optimized) CSS.
## Usage
### Installation using composer
Add php-css-parser to your composer.json
```json
{
"require": {
"sabberworm/php-css-parser": "*"
}
}
```
### Extraction
To use the CSS Parser, create a new instance. The constructor takes the following form:
```php
new Sabberworm\CSS\Parser($sText);
```
To read a file, for example, you’d do the following:
```php
$oCssParser = new Sabberworm\CSS\Parser(file_get_contents('somefile.css'));
$oCssDocument = $oCssParser->parse();
```
The resulting CSS document structure can be manipulated prior to being output.
### Options
#### Charset
The charset option is used only if no @charset declaration is found in the CSS file. UTF-8 is the default, so you won’t have to create a settings object at all if you don’t intend to change that.
```php
$oSettings = Sabberworm\CSS\Settings::create()->withDefaultCharset('windows-1252');
new Sabberworm\CSS\Parser($sText, $oSettings);
```
#### Strict parsing
To have the parser choke on invalid rules, supply a thusly configured Sabberworm\CSS\Settings object:
```php
$oCssParser = new Sabberworm\CSS\Parser(file_get_contents('somefile.css'), Sabberworm\CSS\Settings::create()->beStrict());
```
#### Disable multibyte functions
To achieve faster parsing, you can choose to have PHP-CSS-Parser use regular string functions instead of `mb_*` functions. This should work fine in most cases, even for UTF-8 files, as all the multibyte characters are in string literals. Still it’s not recommended to use this with input you have no control over as it’s not thoroughly covered by test cases.
```php
$oSettings = Sabberworm\CSS\Settings::create()->withMultibyteSupport(false);
new Sabberworm\CSS\Parser($sText, $oSettings);
```
### Manipulation
The resulting data structure consists mainly of five basic types: `CSSList`, `RuleSet`, `Rule`, `Selector` and `Value`. There are two additional types used: `Import` and `Charset` which you won’t use often.
#### CSSList
`CSSList` represents a generic CSS container, most likely containing declaration blocks (rule sets with a selector) but it may also contain at-rules, charset declarations, etc. `CSSList` has the following concrete subtypes:
* `Document` – representing the root of a CSS file.
* `MediaQuery` – represents a subsection of a CSSList that only applies to a output device matching the contained media query.
To access the items stored in a `CSSList` – like the document you got back when calling `$oCssParser->parse()` –, use `getContents()`, then iterate over that collection and use instanceof to check whether you’re dealing with another `CSSList`, a `RuleSet`, a `Import` or a `Charset`.
To append a new item (selector, media query, etc.) to an existing `CSSList`, construct it using the constructor for this class and use the `append($oItem)` method.
#### RuleSet
`RuleSet` is a container for individual rules. The most common form of a rule set is one constrained by a selector. The following concrete subtypes exist:
* `AtRuleSet` – for generic at-rules which do not match the ones specifically mentioned like @import, @charset or @media. A common example for this is @font-face.
* `DeclarationBlock` – a RuleSet constrained by a `Selector`; contains an array of selector objects (comma-separated in the CSS) as well as the rules to be applied to the matching elements.
Note: A `CSSList` can contain other `CSSList`s (and `Import`s as well as a `Charset`) while a `RuleSet` can only contain `Rule`s.
If you want to manipulate a `RuleSet`, use the methods `addRule(Rule $oRule)`, `getRules()` and `removeRule($mRule)` (which accepts either a Rule instance or a rule name; optionally suffixed by a dash to remove all related rules).
#### Rule
`Rule`s just have a key (the rule) and a value. These values are all instances of a `Value`.
#### Value
`Value` is an abstract class that only defines the `render` method. The concrete subclasses for atomic value types are:
* `Size` – consists of a numeric `size` value and a unit.
* `Color` – colors can be input in the form #rrggbb, #rgb or schema(val1, val2, …) but are always stored as an array of ('s' => val1, 'c' => val2, 'h' => val3, …) and output in the second form.
* `CSSString` – this is just a wrapper for quoted strings to distinguish them from keywords; always output with double quotes.
* `URL` – URLs in CSS; always output in URL("") notation.
There is another abstract subclass of `Value`, `ValueList`. A `ValueList` represents a lists of `Value`s, separated by some separation character (mostly `,`, whitespace, or `/`). There are two types of `ValueList`s:
* `RuleValueList` – The default type, used to represent all multi-valued rules like `font: bold 12px/3 Helvetica, Verdana, sans-serif;` (where the value would be a whitespace-separated list of the primitive value `bold`, a slash-separated list and a comma-separated list).
* `CSSFunction` – A special kind of value that also contains a function name and where the values are the function’s arguments. Also handles equals-sign-separated argument lists like `filter: alpha(opacity=90);`.
#### Convenience methods
There are a few convenience methods on Document to ease finding, manipulating and deleting rules:
* `getAllDeclarationBlocks()` – does what it says; no matter how deeply nested your selectors are. Aliased as `getAllSelectors()`.
* `getAllRuleSets()` – does what it says; no matter how deeply nested your rule sets are.
* `getAllValues()` – finds all `Value` objects inside `Rule`s.
## To-Do
* More convenience methods [like `selectorsWithElement($sId/Class/TagName)`, `attributesOfType($sType)`, `removeAttributesOfType($sType)`]
* Real multibyte support. Currently only multibyte charsets whose first 255 code points take up only one byte and are identical with ASCII are supported (yes, UTF-8 fits this description).
* Named color support (using `Color` instead of an anonymous string literal)
## Use cases
### Use `Parser` to prepend an id to all selectors
```php
$sMyId = "#my_id";
$oParser = new Sabberworm\CSS\Parser($sText);
$oCss = $oParser->parse();
foreach($oCss->getAllDeclarationBlocks() as $oBlock) {
foreach($oBlock->getSelectors() as $oSelector) {
//Loop over all selector parts (the comma-separated strings in a selector) and prepend the id
$oSelector->setSelector($sMyId.' '.$oSelector->getSelector());
}
}
```
### Shrink all absolute sizes to half
```php
$oParser = new Sabberworm\CSS\Parser($sText);
$oCss = $oParser->parse();
foreach($oCss->getAllValues() as $mValue) {
if($mValue instanceof CSSSize && !$mValue->isRelative()) {
$mValue->setSize($mValue->getSize()/2);
}
}
```
### Remove unwanted rules
```php
$oParser = new Sabberworm\CSS\Parser($sText);
$oCss = $oParser->parse();
foreach($oCss->getAllRuleSets() as $oRuleSet) {
$oRuleSet->removeRule('font-'); //Note that the added dash will make this remove all rules starting with font- (like font-size, font-weight, etc.) as well as a potential font-rule
$oRuleSet->removeRule('cursor');
}
```
### Output
To output the entire CSS document into a variable, just use `->render()`:
```php
$oCssParser = new Sabberworm\CSS\Parser(file_get_contents('somefile.css'));
$oCssDocument = $oCssParser->parse();
print $oCssDocument->render();
```
If you want to format the output, pass an instance of type `Sabberworm\CSS\OutputFormat`:
```php
$oFormat = Sabberworm\CSS\OutputFormat::create()->indentWithSpaces(4)->setSpaceBetweenRules("\n");
print $oCssDocument->render($oFormat);
```
Or use one