cssom/lib/parse.js

//.CommonJS
var CSSOM = {};
///CommonJS


/**
 * @param {string} token
 */
CSSOM.parse = function parse(token) {

	var i = 0;

	/**
		"before-selector" or
		"selector" or
		"atRule" or
		"atBlock" or
		"conditionBlock" or
		"before-name" or
		"name" or
		"before-value" or
		"value"
	*/
	var state = "before-selector";

	var index;
	var buffer = "";
	var valueParenthesisDepth = 0;

	var SIGNIFICANT_WHITESPACE = {
		"selector": true,
		"value": true,
		"value-parenthesis": true,
		"atRule": true,
		"importRule-begin": true,
		"importRule": true,
		"atBlock": true,
		"conditionBlock": true,
		'documentRule-begin': true
	};

	var styleSheet = new CSSOM.CSSStyleSheet();

	// @type CSSStyleSheet|CSSMediaRule|CSSSupportsRule|CSSFontFaceRule|CSSKeyframesRule|CSSDocumentRule
	var currentScope = styleSheet;

	// @type CSSMediaRule|CSSSupportsRule|CSSKeyframesRule|CSSDocumentRule
	var parentRule;

	var ancestorRules = [];
	var hasAncestors = false;
	var prevScope;

	var name, priority="", styleRule, mediaRule, supportsRule, importRule, fontFaceRule, keyframesRule, documentRule, hostRule;

	var atKeyframesRegExp = /@(-(?:\w+-)+)?keyframes/g;

	var parseError = function(message) {
		var lines = token.substring(0, i).split('\n');
		var lineCount = lines.length;
		var charCount = lines.pop().length + 1;
		var error = new Error(message + ' (line ' + lineCount + ', char ' + charCount + ')');
		error.line = lineCount;
		/* jshint sub : true */
		error['char'] = charCount;
		error.styleSheet = styleSheet;
		throw error;
	};

	for (var character; (character = token.charAt(i)); i++) {

		switch (character) {

		case " ":
		case "\t":
		case "\r":
		case "\n":
		case "\f":
			if (SIGNIFICANT_WHITESPACE[state]) {
				buffer += character;
			}
			break;

		// String
		case '"':
			index = i + 1;
			do {
				index = token.indexOf('"', index) + 1;
				if (!index) {
					parseError('Unmatched "');
				}
			} while (token[index - 2] === '\\');
			buffer += token.slice(i, index);
			i = index - 1;
			switch (state) {
				case 'before-value':
					state = 'value';
					break;
				case 'importRule-begin':
					state = 'importRule';
					break;
			}
			break;

		case "'":
			index = i + 1;
			do {
				index = token.indexOf("'", index) + 1;
				if (!index) {
					parseError("Unmatched '");
				}
			} while (token[index - 2] === '\\');
			buffer += token.slice(i, index);
			i = index - 1;
			switch (state) {
				case 'before-value':
					state = 'value';
					break;
				case 'importRule-begin':
					state = 'importRule';
					break;
			}
			break;

		// Comment
		case "/":
			if (token.charAt(i + 1) === "*") {
				i += 2;
				index = token.indexOf("*/", i);
				if (index === -1) {
					parseError("Missing */");
				} else {
					i = index + 1;
				}
			} else {
				buffer += character;
			}
			if (state === "importRule-begin") {
				buffer += " ";
				state = "importRule";
			}
			break;

		// At-rule
		case "@":
			if (token.indexOf("@-moz-document", i) === i) {
				state = "documentRule-begin";
				documentRule = new CSSOM.CSSDocumentRule();
				documentRule.__starts = i;
				i += "-moz-document".length;
				buffer = "";
				break;
			} else if (token.indexOf("@media", i) === i) {
				state = "atBlock";
				mediaRule = new CSSOM.CSSMediaRule();
				mediaRule.__starts = i;
				i += "media".length;
				buffer = "";
				break;
			} else if (token.indexOf("@supports", i) === i) {
				state = "conditionBlock";
				supportsRule = new CSSOM.CSSSupportsRule();
				supportsRule.__starts = i;
				i += "supports".length;
				buffer = "";
				break;
			} else if (token.indexOf("@host", i) === i) {
				state = "hostRule-begin";
				i += "host".length;
				hostRule = new CSSOM.CSSHostRule();
				hostRule.__starts = i;
				buffer = "";
				break;
			} else if (token.indexOf("@import", i) === i) {
				state = "importRule-begin";
				i += "import".length;
				buffer += "@import";
				break;
			} else if (token.indexOf("@font-face", i) === i) {
				state = "fontFaceRule-begin";
				i += "font-face".length;
				fontFaceRule = new CSSOM.CSSFontFaceRule();
				fontFaceRule.__starts = i;
				buffer = "";
				break;
			} else {
				atKeyframesRegExp.lastIndex = i;
				var matchKeyframes = atKeyframesRegExp.exec(token);
				if (matchKeyframes && matchKeyframes.index === i) {
					state = "keyframesRule-begin";
					keyframesRule = new CSSOM.CSSKeyframesRule();
					keyframesRule.__starts = i;
					keyframesRule._vendorPrefix = matchKeyframes[1]; // Will come out as undefined if no prefix was found
					i += matchKeyframes[0].length - 1;
					buffer = "";
					break;
				} else if (state === "selector") {
					state = "atRule";
				}
			}
			buffer += character;
			break;

		case "{":
			if (state === "selector" || state === "atRule") {
				styleRule.selectorText = buffer.trim();
				styleRule.style.__starts = i;
				buffer = "";
				state = "before-name";
			} else if (state === "atBlock") {
				mediaRule.media.mediaText = buffer.trim();

				if (parentRule) {
					ancestorRules.push(parentRule);
				}

				currentScope = parentRule = mediaRule;
				mediaRule.parentStyleSheet = styleSheet;
				buffer = "";
				state = "before-selector";
			} else if (state === "conditionBlock") {
				supportsRule.conditionText = buffer.trim();

				if (parentRule) {
					ancestorRules.push(parentRule);
				}

				currentScope = parentRule = supportsRule;
				supportsRule.parentStyleSheet = styleSheet;
				buffer = "";
				state = "before-selector";
			} else if (state === "hostRule-begin") {
				if (parentRule) {
					ancestorRules.push(parentRule);
				}

				currentScope = parentRule = hostRule;
				hostRule.parentStyleSheet = styleSheet;
				buffer = "";
				state = "before-selector";
			} else if (state === "fontFaceRule-begin") {
				if (parentRule) {
					ancestorRules.push(parentRule);
					fontFaceRule.parentRule = parentRule;
				}
				fontFaceRule.parentStyleSheet = styleSheet;
				styleRule = fontFaceRule;
				buffer = "";
				state = "before-name";
			} else if (state === "keyframesRule-begin") {
				keyframesRule.name = buffer.trim();
				if (parentRule) {
					ancestorRules.push(parentRule);
					keyframesRule.parentRule = parentRule;
				}
				keyframesRule.parentStyleSheet = styleSheet;
				currentScope = parentRule = keyframesRule;
				buffer = "";
				state = "keyframeRule-begin";
			} else if (state === "keyframeRule-begin") {
				styleRule = new CSSOM.CSSKeyframeRule();
				styleRule.keyText = buffer.trim();
				styleRule.__starts = i;
				buffer = "";
				state = "before-name";
			} else if (state === "documentRule-begin") {
				// FIXME: what if this '{' is in the url text of the match function?
				documentRule.matcher.matcherText = buffer.trim();
				if (parentRule) {
					ancestorRules.push(parentRule);
					documentRule.parentRule = parentRule;
				}
				currentScope = parentRule = documentRule;
				documentRule.parentStyleSheet = styleSheet;
				buffer = "";
				state = "before-selector";
			}
			break;

		case ":":
			if (state === "name") {
				name = buffer.trim();
				buffer = "";
				state = "before-value";
			} else {
				buffer += character;
			}
			break;

		case "(":
			if (state === 'value') {
				// ie css expression mode
				if (buffer.trim() === 'expression') {
					var info = (new CSSOM.CSSValueExpression(token, i)).parse();

					if (info.error) {
						parseError(info.error);
					} else {
						buffer += info.expression;
						i = info.idx;
					}
				} else {
					state = 'value-parenthesis';
					//always ensure this is reset to 1 on transition
					//from value to value-parenthesis
					valueParenthesisDepth = 1;
					buffer += character;
				}
			} else if (state === 'value-parenthesis') {
				valueParenthesisDepth++;
				buffer += character;
			} else {
				buffer += character;
			}
			break;

		case ")":
			if (state === 'value-parenthesis') {
				valueParenthesisDepth--;
				if (valueParenthesisDepth === 0) state = 'value';
			}
			buffer += character;
			break;

		case "!":
			if (state === "value" && token.indexOf("!important", i) === i) {
				priority = "important";
				i += "important".length;
			} else {
				buffer += character;
			}
			break;

		case ";":
			switch (state) {
				case "value":
					styleRule.style.setProperty(name, buffer.trim(), priority);
					priority = "";
					buffer = "";
					state = "before-name";
					break;
				case "atRule":
					buffer = "";
					state = "before-selector";
					break;
				case "importRule":
					importRule = new CSSOM.CSSImportRule();
					importRule.parentStyleSheet = importRule.styleSheet.parentStyleSheet = styleSheet;
					importRule.cssText = buffer + character;
					styleSheet.cssRules.push(importRule);
					buffer = "";
					state = "before-selector";
					break;
				default:
					buffer += character;
					break;
			}
			break;

		case "}":
			switch (state) {
				case "value":
					styleRule.style.setProperty(name, buffer.trim(), priority);
					priority = "";
					/* falls through */
				case "before-name":
				case "name":
					styleRule.__ends = i + 1;
					if (parentRule) {
						styleRule.parentRule = parentRule;
					}
					styleRule.parentStyleSheet = styleSheet;
					currentScope.cssRules.push(styleRule);
					buffer = "";
					if (currentScope.constructor === CSSOM.CSSKeyframesRule) {
						state = "keyframeRule-begin";
					} else {
						state = "before-selector";
					}
					break;
				case "keyframeRule-begin":
				case "before-selector":
				case "selector":
					// End of media/supports/document rule.
					if (!parentRule) {
						parseError("Unexpected }");
					}

					// Handle rules nested in @media or @supports
					hasAncestors = ancestorRules.length > 0;

					while (ancestorRules.length > 0) {
						parentRule = ancestorRules.pop();

						if (
							parentRule.constructor.name === "CSSMediaRule"
							|| parentRule.constructor.name === "CSSSupportsRule"
						) {
							prevScope = currentScope;
							currentScope = parentRule;
							currentScope.cssRules.push(prevScope);
							break;
						}

						if (ancestorRules.length === 0) {
							hasAncestors = false;
						}
					}
					
					if (!hasAncestors) {
						currentScope.__ends = i + 1;
						styleSheet.cssRules.push(currentScope);
						currentScope = styleSheet;
						parentRule = null;
					}

					buffer = "";
					state = "before-selector";
					break;
			}
			break;

		default:
			switch (state) {
				case "before-selector":
					state = "selector";
					styleRule = new CSSOM.CSSStyleRule();
					styleRule.__starts = i;
					break;
				case "before-name":
					state = "name";
					break;
				case "before-value":
					state = "value";
					break;
				case "importRule-begin":
					state = "importRule";
					break;
			}
			buffer += character;
			break;
		}
	}

	return styleSheet;
};


//.CommonJS
exports.parse = CSSOM.parse;
// The following modules cannot be included sooner due to the mutual dependency with parse.js
CSSOM.CSSStyleSheet = require("./CSSStyleSheet").CSSStyleSheet;
CSSOM.CSSStyleRule = require("./CSSStyleRule").CSSStyleRule;
CSSOM.CSSImportRule = require("./CSSImportRule").CSSImportRule;
CSSOM.CSSMediaRule = require("./CSSMediaRule").CSSMediaRule;
CSSOM.CSSSupportsRule = require("./CSSSupportsRule").CSSSupportsRule;
CSSOM.CSSFontFaceRule = require("./CSSFontFaceRule").CSSFontFaceRule;
CSSOM.CSSHostRule = require("./CSSHostRule").CSSHostRule;
CSSOM.CSSStyleDeclaration = require('./CSSStyleDeclaration').CSSStyleDeclaration;
CSSOM.CSSKeyframeRule = require('./CSSKeyframeRule').CSSKeyframeRule;
CSSOM.CSSKeyframesRule = require('./CSSKeyframesRule').CSSKeyframesRule;
CSSOM.CSSValueExpression = require('./CSSValueExpression').CSSValueExpression;
CSSOM.CSSDocumentRule = require('./CSSDocumentRule').CSSDocumentRule;
///CommonJS