Gonzales PE @dev

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Gonzales PE is a CSS parser which plays nicely with preprocessors.
Currently those are supported: SCSS, Sass, LESS.
Try out Gonzales PE online: Gonzales PE Playground.

Install

(1) To install command-line tool globally:

``bash
npm install -g git://github.com/tonyganch/gonzales-pe.git#dev
`

(2) To install parser as a project dependency:

`bash
npm install --save git://github.com/tonyganch/gonzales-pe.git#dev
`

(3) If for some reason you want to build files yourself:

`bash


Clone the repo.

git clone git@github.com:tonyganch/gonzales-pe.git

Go to dev branch.

git checkout dev

Install project dependencies.

npm install

Install git hooks and build files.

npm run init
`

API

Basically there are a few things you can do:

1. parse css string and get a parse tree in return;
2. modify tree nodes;
3. remove tree nodes;
4. add new nodes to the tree;
5. convert modified tree back to a string.

The different type of tree nodes can be found in docs/node-types.md.

In examples below I assume that gonzales is a parser module and parseTree
is some parsed css:

`js
let gonzales = require('gonzales-pe');
let parseTree = gonzales.parse(css);
`

$3

##### Description

Creates a new node. Useful when you need to add something to a tree.

##### Parameters










{Object}	options	Options to pass to a Node constructor.

##### Returns








{Object}

A new node.

##### Examples

`js
let css = 'a {color: tomato}';
let parseTree = gonzales.parse(css);
let node = gonzales.createNode({ type: 'animal', content: 'panda' });
parseTree.content.push(node);
`




$3

##### Description

Parses a css string.

##### Parameters














{string}	css	A string to parse.
{Object=}	options	Optional. Additional options: {string} syntax — any of the following: css, less, sass, scss. Default one is css. {string} context — root node's type. For a list of available values see "Node types". Default one is stylesheet. {number} tabSize — size of a tab character in spaces. Default one is 1.

##### Returns








{Object}

Parse tree.

##### Examples

`js
let css = 'a {color: tomato}';
let parseTree = gonzales.parse(css);
`

`js
let less = 'a {$color: tomato}';
let parseTree = gonzales.parse(less, {syntax: 'less'});
`

`js
let less = '$color: tomato';
let parseTree = gonzales.parse(less, {syntax: 'less', rule: 'declaration'});
`

$3

##### Description

Checks whether there is a child node of given type.

##### Parameters









{string}

type

Node type we're looking for. For a list of available values see "Node types".

##### Returns








{boolean}

true if a tree contains a child node of a given type, false otherwise.

##### Examples

`js
if (parseTree.contains('space')) {
doSomething();
}
`

$3

##### Returns








{string|Array}

Node's content (child nodes or a string).

$3

##### Description

Calls a function for every child node in tree. If type parameter is passed,
calls a function only for child nodes of a given type. The main difference from
parseTree.forEach() is that this method loops through node list from the end
to beginning.

##### Parameters














{string=}	type	Optional. A node type by which to filter child nodes before applying a callback function. For a list of available values see "Node types".
{Function}	callback	Function to call for every child node. Accepts following parameters: {Object} — a child node; {number} — index of the child node in node list; {Object} — parent node (equals to parseTree).

##### Examples

`js
parseTree.eachFor(function(childNode) {
doSomething(childNode);
});
`

`js
// Remove all child spaces.
parseTree.eachFor('space', function(spaceNode, i) {
parseTree.removeChild(i);
});
`

$3

##### Returns








{Object}

End position of the node. Contains following info: {number} line — last symbol's line number (1-based index); {number} column — last symbol's column number (1-based index).

$3

##### Description

Gets the first child node. If type parameter is passed, gets the first child
node of a given type. If no node has been found, returns null.

##### Parameters









{string=}

type

Optional. Node type to look for. For a list of available values see "Node types".

##### Returns








{?Object}

A node.

##### Examples

`js
let node = parseTree.first();
node.content = 'panda';
`

`js
let node = parseTree.first('multilineComment');
node.content = 'panda';
`

$3

##### Description

Calls a function for every child node in tree. If type parameter is passed,
calls a function only for child nodes of a given type. The main difference from
parseTree.eachFor() is that this method loops through node list from the
beginnig to end.

##### Parameters














{string=}	type	Optional. A node type by which to filter child nodes before applying a callback function. For a list of available values see "Node types".
{Function}	callback	Function to call for every child node. Accepts following parameters: {Object} — a child node; {number} — index of the child node in node list; {Object} — parent node (equals to parseTree).

##### Examples

`js
parseTree.forEach(function(childNode) {
doSomething();
});
`

`js
parseTree.forEach('space', function(spaceNode) {
doSomething();
});
`

$3

##### Description

Gets nth child of the parseTree. If no node has been found, returns null.

##### Parameters









{number}

index

Index number of node which we're looking for.

##### Returns








{?Object}

A node.

##### Examples

`js
var node = parseTree.get(2);
doSomething(node);
`

$3

##### Description

Inserts a node to a given position in parseTree.

##### Parameters














{number}	index	Index of position where to insert the node.
{Object}	node	A node to insert.

##### Examples

`js
let node = gonzales.createNode({type: 'animal', content: 'panda'});
parseTree.insert(2, node);
`

$3

##### Description

Checks whether the node is of given type.

##### Parameters









{string}

type

A node type against which to check type of parseTree. For a list of available values see "Node types".

##### Returns








{boolean}

true if types are equal, false otherwise.

##### Examples

`js
if (node.is('space')) {
node.content = '';
}
`

$3

Gets the last child node. If type parameter is passed, gets the last child
node of a given type. If no node has been found, returns null.

##### Parameters









{string=}

type

Optional. Node type to look for. For a list of available values see "Node types".

##### Returns








{?Object}

A node.

##### Examples

`js
let node = parseTree.last();
node.content = 'panda';
`

`js
let node = parseTree.last('multilineComment');
node.content = 'panda';
`

$3

##### Returns








{number}

Number of child nodes.

$3

##### Description

Removes a child node at a given position.

##### Parameters









{number}

index

Index of a child node we need to remove.

##### Returns








{Object}

Removed node.

##### Examples

`js
// Swap nodes.
var node = parseTree.removeChild(1);
parseTree.insert(0, node);
`

$3

##### Returns








{Object}

Start position of the node. Contains following info: {number} line — first symbol's line number (1-based index); {number} column — first symbol's column number (1-based index).




$3

##### Returns








{string}

Syntax of original parsed string.

$3

##### Description

Converts parse tree to JSON. Useful for printing.

##### Returns








{Object}

Parse tree in JSON

$3

##### Description

Converts parse tree back to string according to original syntax.

##### Returns








{string}

A compiled string.

##### Examples

`js
let css = parseTree.toString();
`

$3

##### Description

Calls the function for every node in a tree including parseTree itself.

##### Parameters









{Function}

callback

Function to apply to every node. Accepts following parameters: {Object} — a node to which we apply callback; {number} — node's index number inside its parent; {Object} — a node's parent; {number} — node's nesting level relative to its parent.

##### Examples

`js
parseTree.traverse(function(node, index, parent) {
if (node.is('multilineComment')) {
parent.removeChild(index);
} else if (node.is('space')) {
node.content = ' ';
}
});
`

$3

##### Description

This method should be called for a root node, because calling it for a child
will be more time consuming.
Calls the function for every node of a given type. This means not just child
nodes, but grandchilds and so on.

##### Parameters














{string}	type	Node type. For a list of available values please see "Node types".
{Function}	callback	Function to apply to every node of a given type. Accepts following parameters: {Object} — a node to which we apply callback; {number} — node's index number inside its parent; {Object} — a node's parent.

##### Examples

`js
// Remove all comments.
parseTree.traverseByType('multilineComment', function(node, index, parent) {
parent.removeChild(index);
});
`

$3

##### Description

This method should be called for a root node, because calling it for a child
will be more time consuming.
Calls the function for every node of given types. This means not just child
nodes, but grandchilds and so on.

##### Parameters














{Array.string}	types	List of node types. For a list of available values please see "Node types".
{Function}	callback	Function to apply to every node of given types. Accepts following parameters: {Object} — a node to which we apply callback; {number} — node's index number inside its parent; {Object} — a node's parent.

##### Examples

`js
// Remove all comments and spaces.
let types = ['multilineComment', 'space'];
parseTree.traverseByTypes(types, function(node, index, parent) {
parent.removeChild(index);
});
`

$3

##### Returns








{string}

Node type. For a list of available values see "Node types".




Test

To run tests:

npm test

This command will build library files from sources and run tests on all files
in syntax directories.

Every test has 3 files: source stylesheet, expected parse tree and expected
string compiled back from parse tree to css.

If some tests fail, you can find information in test logs:

- log/test.log contains all information from stdout;
- log/expected.txt contains only expected text;
- log/result.txt contains only result text.

The last two are made for your convenience: you can use any diff app to see
the defference between them.

If you want to test one specific string or get a general idea of how Gonzales
works, you can use test/ast.js file.
Simply change the first two strings (css and syntax` vars) and run:

node test/single-test.js

Report

If you find a bug or want to add a feature, welcome to Issues.

If you are shy but have a question, feel free to drop me a
line.