gecko-dev/devtools/shared/css-parsing-utils.js

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JavaScript

/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
/* vim: set ts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
// This file holds various CSS parsing and rewriting utilities.
// Some entry points of note are:
// parseDeclarations - parse a CSS rule into declarations
// RuleRewriter - rewrite CSS rule text
// parsePseudoClassesAndAttributes - parse selector and extract
// pseudo-classes
// parseSingleValue - parse a single CSS property value
"use strict";
loader.lazyRequireGetter(this, "CSS", "CSS");
const promise = require("promise");
const {getCSSLexer} = require("devtools/shared/css-lexer");
const {Task} = require("devtools/shared/task");
const SELECTOR_ATTRIBUTE = exports.SELECTOR_ATTRIBUTE = 1;
const SELECTOR_ELEMENT = exports.SELECTOR_ELEMENT = 2;
const SELECTOR_PSEUDO_CLASS = exports.SELECTOR_PSEUDO_CLASS = 3;
// Used to test whether a newline appears anywhere in some text.
const NEWLINE_RX = /[\r\n]/;
// Used to test whether a bit of text starts an empty comment, either
// an "ordinary" /* ... */ comment, or a "heuristic bypass" comment
// like /*! ... */.
const EMPTY_COMMENT_START_RX = /^\/\*!?[ \r\n\t\f]*$/;
// Used to test whether a bit of text ends an empty comment.
const EMPTY_COMMENT_END_RX = /^[ \r\n\t\f]*\*\//;
// Used to test whether a string starts with a blank line.
const BLANK_LINE_RX = /^[ \t]*(?:\r\n|\n|\r|\f|$)/;
// When commenting out a declaration, we put this character into the
// comment opener so that future parses of the commented text know to
// bypass the property name validity heuristic.
const COMMENT_PARSING_HEURISTIC_BYPASS_CHAR = "!";
/**
* A generator function that lexes a CSS source string, yielding the
* CSS tokens. Comment tokens are dropped.
*
* @param {String} CSS source string
* @yield {CSSToken} The next CSSToken that is lexed
* @see CSSToken for details about the returned tokens
*/
function* cssTokenizer(string) {
let lexer = getCSSLexer(string);
while (true) {
let token = lexer.nextToken();
if (!token) {
break;
}
// None of the existing consumers want comments.
if (token.tokenType !== "comment") {
yield token;
}
}
}
/**
* Pass |string| to the CSS lexer and return an array of all the
* returned tokens. Comment tokens are not included. In addition to
* the usual information, each token will have starting and ending
* line and column information attached. Specifically, each token
* has an additional "loc" attribute. This attribute is an object
* of the form {line: L, column: C}. Lines and columns are both zero
* based.
*
* It's best not to add new uses of this function. In general it is
* simpler and better to use the CSSToken offsets, rather than line
* and column. Also, this function lexes the entire input string at
* once, rather than lazily yielding a token stream. Use
* |cssTokenizer| or |getCSSLexer| instead.
*
* @param{String} string The input string.
* @return {Array} An array of tokens (@see CSSToken) that have
* line and column information.
*/
function cssTokenizerWithLineColumn(string) {
let lexer = getCSSLexer(string);
let result = [];
let prevToken = undefined;
while (true) {
let token = lexer.nextToken();
let lineNumber = lexer.lineNumber;
let columnNumber = lexer.columnNumber;
if (prevToken) {
prevToken.loc.end = {
line: lineNumber,
column: columnNumber
};
}
if (!token) {
break;
}
if (token.tokenType === "comment") {
// We've already dealt with the previous token's location.
prevToken = undefined;
} else {
let startLoc = {
line: lineNumber,
column: columnNumber
};
token.loc = {start: startLoc};
result.push(token);
prevToken = token;
}
}
return result;
}
/**
* Escape a comment body. Find the comment start and end strings in a
* string and inserts backslashes so that the resulting text can
* itself be put inside a comment.
*
* @param {String} inputString
* input string
* @return {String} the escaped result
*/
function escapeCSSComment(inputString) {
let result = inputString.replace(/\/(\\*)\*/g, "/\\$1*");
return result.replace(/\*(\\*)\//g, "*\\$1/");
}
/**
* Un-escape a comment body. This undoes any comment escaping that
* was done by escapeCSSComment. That is, given input like "/\*
* comment *\/", it will strip the backslashes.
*
* @param {String} inputString
* input string
* @return {String} the un-escaped result
*/
function unescapeCSSComment(inputString) {
let result = inputString.replace(/\/\\(\\*)\*/g, "/$1*");
return result.replace(/\*\\(\\*)\//g, "*$1/");
}
/**
* A helper function for @see parseDeclarations that handles parsing
* of comment text. This wraps a recursive call to parseDeclarations
* with the processing needed to ensure that offsets in the result
* refer back to the original, unescaped, input string.
*
* @param {Function} isCssPropertyKnown
* A function to check if the CSS property is known. This is either an
* internal server function or from the CssPropertiesFront.
* @param {String} commentText The text of the comment, without the
* delimiters.
* @param {Number} startOffset The offset of the comment opener
* in the original text.
* @param {Number} endOffset The offset of the comment closer
* in the original text.
* @return {array} Array of declarations of the same form as returned
* by parseDeclarations.
*/
function parseCommentDeclarations(isCssPropertyKnown, commentText, startOffset,
endOffset) {
let commentOverride = false;
if (commentText === "") {
return [];
} else if (commentText[0] === COMMENT_PARSING_HEURISTIC_BYPASS_CHAR) {
// This is the special sign that the comment was written by
// rewriteDeclarations and so we should bypass the usual
// heuristic.
commentOverride = true;
commentText = commentText.substring(1);
}
let rewrittenText = unescapeCSSComment(commentText);
// We might have rewritten an embedded comment. For example
// /\* ... *\/ would turn into /* ... */.
// This rewriting is necessary for proper lexing, but it means
// that the offsets we get back can be off. So now we compute
// a map so that we can rewrite offsets later. The map is the same
// length as |rewrittenText| and tells us how to map an index
// into |rewrittenText| to an index into |commentText|.
//
// First, we find the location of each comment starter or closer in
// |rewrittenText|. At these spots we put a 1 into |rewrites|.
// Then we walk the array again, using the elements to compute a
// delta, which we use to make the final mapping.
//
// Note we allocate one extra entry because we can see an ending
// offset that is equal to the length.
let rewrites = new Array(rewrittenText.length + 1).fill(0);
let commentRe = /\/\\*\*|\*\\*\//g;
while (true) {
let matchData = commentRe.exec(rewrittenText);
if (!matchData) {
break;
}
rewrites[matchData.index] = 1;
}
let delta = 0;
for (let i = 0; i <= rewrittenText.length; ++i) {
delta += rewrites[i];
// |startOffset| to add the offset from the comment starter, |+2|
// for the length of the "/*", then |i| and |delta| as described
// above.
rewrites[i] = startOffset + 2 + i + delta;
if (commentOverride) {
++rewrites[i];
}
}
// Note that we pass "false" for parseComments here. It doesn't
// seem worthwhile to support declarations in comments-in-comments
// here, as there's no way to generate those using the tools, and
// users would be crazy to write such things.
let newDecls = parseDeclarationsInternal(isCssPropertyKnown, rewrittenText,
false, true, commentOverride);
for (let decl of newDecls) {
decl.offsets[0] = rewrites[decl.offsets[0]];
decl.offsets[1] = rewrites[decl.offsets[1]];
decl.colonOffsets[0] = rewrites[decl.colonOffsets[0]];
decl.colonOffsets[1] = rewrites[decl.colonOffsets[1]];
decl.commentOffsets = [startOffset, endOffset];
}
return newDecls;
}
/**
* A helper function for parseDeclarationsInternal that creates a new
* empty declaration.
*
* @return {object} an empty declaration of the form returned by
* parseDeclarations
*/
function getEmptyDeclaration() {
return {name: "", value: "", priority: "",
terminator: "",
offsets: [undefined, undefined],
colonOffsets: false};
}
/**
* A helper function that does all the parsing work for
* parseDeclarations. This is separate because it has some arguments
* that don't make sense in isolation.
*
* The return value and arguments are like parseDeclarations, with
* these additional arguments.
*
* @param {Function} isCssPropertyKnown
* Function to check if the CSS property is known.
* @param {Boolean} inComment
* If true, assume that this call is parsing some text
* which came from a comment in another declaration.
* In this case some heuristics are used to avoid parsing
* text which isn't obviously a series of declarations.
* @param {Boolean} commentOverride
* This only makes sense when inComment=true.
* When true, assume that the comment was generated by
* rewriteDeclarations, and skip the usual name-checking
* heuristic.
*/
function parseDeclarationsInternal(isCssPropertyKnown, inputString,
parseComments, inComment, commentOverride) {
if (inputString === null || inputString === undefined) {
throw new Error("empty input string");
}
let lexer = getCSSLexer(inputString);
let declarations = [getEmptyDeclaration()];
let lastProp = declarations[0];
let current = "", hasBang = false;
while (true) {
let token = lexer.nextToken();
if (!token) {
break;
}
// Ignore HTML comment tokens (but parse anything they might
// happen to surround).
if (token.tokenType === "htmlcomment") {
continue;
}
// Update the start and end offsets of the declaration, but only
// when we see a significant token.
if (token.tokenType !== "whitespace" && token.tokenType !== "comment") {
if (lastProp.offsets[0] === undefined) {
lastProp.offsets[0] = token.startOffset;
}
lastProp.offsets[1] = token.endOffset;
} else if (lastProp.name && !current && !hasBang &&
!lastProp.priority && lastProp.colonOffsets[1]) {
// Whitespace appearing after the ":" is attributed to it.
lastProp.colonOffsets[1] = token.endOffset;
}
if (token.tokenType === "symbol" && token.text === ":") {
if (!lastProp.name) {
// Set the current declaration name if there's no name yet
lastProp.name = current.trim();
lastProp.colonOffsets = [token.startOffset, token.endOffset];
current = "";
hasBang = false;
// When parsing a comment body, if the left-hand-side is not a
// valid property name, then drop it and stop parsing.
if (inComment && !commentOverride &&
!isCssPropertyKnown(lastProp.name)) {
lastProp.name = null;
break;
}
} else {
// Otherwise, just append ':' to the current value (declaration value
// with colons)
current += ":";
}
} else if (token.tokenType === "symbol" && token.text === ";") {
lastProp.terminator = "";
// When parsing a comment, if the name hasn't been set, then we
// have probably just seen an ordinary semicolon used in text,
// so drop this and stop parsing.
if (inComment && !lastProp.name) {
current = "";
break;
}
lastProp.value = current.trim();
current = "";
hasBang = false;
declarations.push(getEmptyDeclaration());
lastProp = declarations[declarations.length - 1];
} else if (token.tokenType === "ident") {
if (token.text === "important" && hasBang) {
lastProp.priority = "important";
hasBang = false;
} else {
if (hasBang) {
current += "!";
}
current += token.text;
}
} else if (token.tokenType === "symbol" && token.text === "!") {
hasBang = true;
} else if (token.tokenType === "whitespace") {
if (current !== "") {
current += " ";
}
} else if (token.tokenType === "comment") {
if (parseComments && !lastProp.name && !lastProp.value) {
let commentText = inputString.substring(token.startOffset + 2,
token.endOffset - 2);
let newDecls = parseCommentDeclarations(isCssPropertyKnown, commentText,
token.startOffset,
token.endOffset);
// Insert the new declarations just before the final element.
let lastDecl = declarations.pop();
declarations = [...declarations, ...newDecls, lastDecl];
}
} else {
current += inputString.substring(token.startOffset, token.endOffset);
}
}
// Handle whatever trailing properties or values might still be there
if (current) {
if (!lastProp.name) {
// Ignore this case in comments.
if (!inComment) {
// Trailing property found, e.g. p1:v1;p2:v2;p3
lastProp.name = current.trim();
}
} else {
// Trailing value found, i.e. value without an ending ;
lastProp.value = current.trim();
let terminator = lexer.performEOFFixup("", true);
lastProp.terminator = terminator + ";";
// If the input was unterminated, attribute the remainder to
// this property. This avoids some bad behavior when rewriting
// an unterminated comment.
if (terminator) {
lastProp.offsets[1] = inputString.length;
}
}
}
// Remove declarations that have neither a name nor a value
declarations = declarations.filter(prop => prop.name || prop.value);
return declarations;
}
/**
* Returns an array of CSS declarations given a string.
* For example, parseDeclarations(isCssPropertyKnown, "width: 1px; height: 1px")
* would return:
* [{name:"width", value: "1px"}, {name: "height", "value": "1px"}]
*
* The input string is assumed to only contain declarations so { and }
* characters will be treated as part of either the property or value,
* depending where it's found.
*
* @param {Function} isCssPropertyKnown
* A function to check if the CSS property is known. This is either an
* internal server function or from the CssPropertiesFront.
* that are supported by the server.
* @param {String} inputString
* An input string of CSS
* @param {Boolean} parseComments
* If true, try to parse the contents of comments as well.
* A comment will only be parsed if it occurs outside of
* the body of some other declaration.
* @return {Array} an array of objects with the following signature:
* [{"name": string, "value": string, "priority": string,
* "terminator": string,
* "offsets": [start, end], "colonOffsets": [start, end]},
* ...]
* Here, "offsets" holds the offsets of the start and end
* of the declaration text, in a form suitable for use with
* String.substring.
* "terminator" is a string to use to terminate the declaration,
* usually "" to mean no additional termination is needed.
* "colonOffsets" holds the start and end locations of the
* ":" that separates the property name from the value.
* If the declaration appears in a comment, then there will
* be an additional {"commentOffsets": [start, end] property
* on the object, which will hold the offsets of the start
* and end of the enclosing comment.
*/
function parseDeclarations(isCssPropertyKnown, inputString,
parseComments = false) {
return parseDeclarationsInternal(isCssPropertyKnown, inputString,
parseComments, false, false);
}
/**
* Return an object that can be used to rewrite declarations in some
* source text. The source text and parsing are handled in the same
* way as @see parseDeclarations, with |parseComments| being true.
* Rewriting is done by calling one of the modification functions like
* setPropertyEnabled. The returned object has the same interface
* as @see RuleModificationList.
*
* An example showing how to disable the 3rd property in a rule:
*
* let rewriter = new RuleRewriter(isCssPropertyKnown, ruleActor,
* ruleActor.authoredText);
* rewriter.setPropertyEnabled(3, "color", false);
* rewriter.apply().then(() => { ... the change is made ... });
*
* The exported rewriting methods are |renameProperty|, |setPropertyEnabled|,
* |createProperty|, |setProperty|, and |removeProperty|. The |apply|
* method can be used to send the edited text to the StyleRuleActor;
* |getDefaultIndentation| is useful for the methods requiring a
* default indentation value; and |getResult| is useful for testing.
*
* Additionally, editing will set the |changedDeclarations| property
* on this object. This property has the same form as the |changed|
* property of the object returned by |getResult|.
*
* @param {Function} isCssPropertyKnown
* A function to check if the CSS property is known. This is either an
* internal server function or from the CssPropertiesFront.
* that are supported by the server. Note that if Bug 1222047
* is completed then isCssPropertyKnown will not need to be passed in.
* The CssProperty front will be able to obtained directly from the
* RuleRewriter.
* @param {StyleRuleFront} rule The style rule to use. Note that this
* is only needed by the |apply| and |getDefaultIndentation| methods;
* and in particular for testing it can be |null|.
* @param {String} inputString The CSS source text to parse and modify.
* @return {Object} an object that can be used to rewrite the input text.
*/
function RuleRewriter(isCssPropertyKnown, rule, inputString) {
this.rule = rule;
this.inputString = inputString;
// Whether there are any newlines in the input text.
this.hasNewLine = /[\r\n]/.test(this.inputString);
// Keep track of which any declarations we had to rewrite while
// performing the requested action.
this.changedDeclarations = {};
// The declarations.
this.declarations = parseDeclarations(isCssPropertyKnown, this.inputString,
true);
this.decl = null;
this.result = null;
// If not null, a promise that must be wait upon before |apply| can
// do its work.
this.editPromise = null;
// If the |defaultIndentation| property is set, then it is used;
// otherwise the RuleRewriter will try to compute the default
// indentation based on the style sheet's text. This override
// facility is for testing.
this.defaultIndentation = null;
}
RuleRewriter.prototype = {
/**
* An internal function to complete initialization and set some
* properties for further processing.
*
* @param {Number} index The index of the property to modify
*/
completeInitialization: function (index) {
if (index < 0) {
throw new Error("Invalid index " + index + ". Expected positive integer");
}
// |decl| is the declaration to be rewritten, or null if there is no
// declaration corresponding to |index|.
// |result| is used to accumulate the result text.
if (index < this.declarations.length) {
this.decl = this.declarations[index];
this.result = this.inputString.substring(0, this.decl.offsets[0]);
} else {
this.decl = null;
this.result = this.inputString;
}
},
/**
* A helper function to compute the indentation of some text. This
* examines the rule's existing text to guess the indentation to use;
* unlike |getDefaultIndentation|, which examines the entire style
* sheet.
*
* @param {String} string the input text
* @param {Number} offset the offset at which to compute the indentation
* @return {String} the indentation at the indicated position
*/
getIndentation: function (string, offset) {
let originalOffset = offset;
for (--offset; offset >= 0; --offset) {
let c = string[offset];
if (c === "\r" || c === "\n" || c === "\f") {
return string.substring(offset + 1, originalOffset);
}
if (c !== " " && c !== "\t") {
// Found some non-whitespace character before we found a newline
// -- let's reset the starting point and keep going, as we saw
// something on the line before the declaration.
originalOffset = offset;
}
}
// Ran off the end.
return "";
},
/**
* Modify a property value to ensure it is "lexically safe" for
* insertion into a style sheet. This function doesn't attempt to
* ensure that the resulting text is a valid value for the given
* property; but rather just that inserting the text into the style
* sheet will not cause unwanted changes to other rules or
* declarations.
*
* @param {String} text The input text. This should include the trailing ";".
* @return {Array} An array of the form [anySanitized, text], where
* |anySanitized| is a boolean that indicates
* whether anything substantive has changed; and
* where |text| is the text that has been rewritten
* to be "lexically safe".
*/
sanitizePropertyValue: function (text) {
let lexer = getCSSLexer(text);
let result = "";
let previousOffset = 0;
let braceDepth = 0;
let anySanitized = false;
while (true) {
let token = lexer.nextToken();
if (!token) {
break;
}
if (token.tokenType === "symbol") {
switch (token.text) {
case ";":
// We simply drop the ";" here. This lets us cope with
// declarations that don't have a ";" and also other
// termination. The caller handles adding the ";" again.
result += text.substring(previousOffset, token.startOffset);
previousOffset = token.endOffset;
break;
case "{":
++braceDepth;
break;
case "}":
--braceDepth;
if (braceDepth < 0) {
// Found an unmatched close bracket.
braceDepth = 0;
// Copy out text from |previousOffset|.
result += text.substring(previousOffset, token.startOffset);
// Quote the offending symbol.
result += "\\" + token.text;
previousOffset = token.endOffset;
anySanitized = true;
}
break;
}
}
}
// Copy out any remaining text, then any needed terminators.
result += text.substring(previousOffset, text.length);
let eofFixup = lexer.performEOFFixup("", true);
if (eofFixup) {
anySanitized = true;
result += eofFixup;
}
return [anySanitized, result];
},
/**
* Start at |index| and skip whitespace
* backward in |string|. Return the index of the first
* non-whitespace character, or -1 if the entire string was
* whitespace.
* @param {String} string the input string
* @param {Number} index the index at which to start
* @return {Number} index of the first non-whitespace character, or -1
*/
skipWhitespaceBackward: function (string, index) {
for (--index;
index >= 0 && (string[index] === " " || string[index] === "\t");
--index) {
// Nothing.
}
return index;
},
/**
* Terminate a given declaration, if needed.
*
* @param {Number} index The index of the rule to possibly
* terminate. It might be invalid, so this
* function must check for that.
*/
maybeTerminateDecl: function (index) {
if (index < 0 || index >= this.declarations.length
// No need to rewrite declarations in comments.
|| ("commentOffsets" in this.declarations[index])) {
return;
}
let termDecl = this.declarations[index];
let endIndex = termDecl.offsets[1];
// Due to an oddity of the lexer, we might have gotten a bit of
// extra whitespace in a trailing bad_url token -- so be sure to
// skip that as well.
endIndex = this.skipWhitespaceBackward(this.result, endIndex) + 1;
let trailingText = this.result.substring(endIndex);
if (termDecl.terminator) {
// Insert the terminator just at the end of the declaration,
// before any trailing whitespace.
this.result = this.result.substring(0, endIndex) + termDecl.terminator +
trailingText;
// In a couple of cases, we may have had to add something to
// terminate the declaration, but the termination did not
// actually affect the property's value -- and at this spot, we
// only care about reporting value changes. In particular, we
// might have added a plain ";", or we might have terminated a
// comment with "*/;". Neither of these affect the value.
if (termDecl.terminator !== ";" && termDecl.terminator !== "*/;") {
this.changedDeclarations[index] =
termDecl.value + termDecl.terminator.slice(0, -1);
}
}
// If the rule generally has newlines, but this particular
// declaration doesn't have a trailing newline, insert one now.
// Maybe this style is too weird to bother with.
if (this.hasNewLine && !NEWLINE_RX.test(trailingText)) {
this.result += "\n";
}
},
/**
* Sanitize the given property value and return the sanitized form.
* If the property is rewritten during sanitization, make a note in
* |changedDeclarations|.
*
* @param {String} text The property text.
* @param {Number} index The index of the property.
* @return {String} The sanitized text.
*/
sanitizeText: function (text, index) {
let [anySanitized, sanitizedText] = this.sanitizePropertyValue(text);
if (anySanitized) {
this.changedDeclarations[index] = sanitizedText;
}
return sanitizedText;
},
/**
* Rename a declaration.
*
* @param {Number} index index of the property in the rule.
* @param {String} name current name of the property
* @param {String} newName new name of the property
*/
renameProperty: function (index, name, newName) {
this.completeInitialization(index);
this.result += CSS.escape(newName);
// We could conceivably compute the name offsets instead so we
// could preserve white space and comments on the LHS of the ":".
this.completeCopying(this.decl.colonOffsets[0]);
},
/**
* Enable or disable a declaration
*
* @param {Number} index index of the property in the rule.
* @param {String} name current name of the property
* @param {Boolean} isEnabled true if the property should be enabled;
* false if it should be disabled
*/
setPropertyEnabled: function (index, name, isEnabled) {
this.completeInitialization(index);
const decl = this.decl;
let copyOffset = decl.offsets[1];
if (isEnabled) {
// Enable it. First see if the comment start can be deleted.
let commentStart = decl.commentOffsets[0];
if (EMPTY_COMMENT_START_RX.test(this.result.substring(commentStart))) {
this.result = this.result.substring(0, commentStart);
} else {
this.result += "*/ ";
}
// Insert the name and value separately, so we can report
// sanitization changes properly.
let commentNamePart =
this.inputString.substring(decl.offsets[0],
decl.colonOffsets[1]);
this.result += unescapeCSSComment(commentNamePart);
// When uncommenting, we must be sure to sanitize the text, to
// avoid things like /* decl: }; */, which will be accepted as
// a property but which would break the entire style sheet.
let newText = this.inputString.substring(decl.colonOffsets[1],
decl.offsets[1]);
newText = unescapeCSSComment(newText).trimRight();
this.result += this.sanitizeText(newText, index) + ";";
// See if the comment end can be deleted.
let trailingText = this.inputString.substring(decl.offsets[1]);
if (EMPTY_COMMENT_END_RX.test(trailingText)) {
copyOffset = decl.commentOffsets[1];
} else {
this.result += " /*";
}
} else {
// Disable it. Note that we use our special comment syntax
// here.
let declText = this.inputString.substring(decl.offsets[0],
decl.offsets[1]);
this.result += "/*" + COMMENT_PARSING_HEURISTIC_BYPASS_CHAR +
" " + escapeCSSComment(declText) + " */";
}
this.completeCopying(copyOffset);
},
/**
* Return a promise that will be resolved to the default indentation
* of the rule. This is a helper for internalCreateProperty.
*
* @return {Promise} a promise that will be resolved to a string
* that holds the default indentation that should be used
* for edits to the rule.
*/
getDefaultIndentation: function () {
return this.rule.parentStyleSheet.guessIndentation();
},
/**
* An internal function to create a new declaration. This does all
* the work of |createProperty|.
*
* @param {Number} index index of the property in the rule.
* @param {String} name name of the new property
* @param {String} value value of the new property
* @param {String} priority priority of the new property; either
* the empty string or "important"
* @return {Promise} a promise that is resolved when the edit has
* completed
*/
internalCreateProperty: Task.async(function* (index, name, value, priority) {
this.completeInitialization(index);
let newIndentation = "";
if (this.hasNewLine) {
if (this.declarations.length > 0) {
newIndentation = this.getIndentation(this.inputString,
this.declarations[0].offsets[0]);
} else if (this.defaultIndentation) {
newIndentation = this.defaultIndentation;
} else {
newIndentation = yield this.getDefaultIndentation();
}
}
this.maybeTerminateDecl(index - 1);
// If we generally have newlines, and if skipping whitespace
// backward stops at a newline, then insert our text before that
// whitespace. This ensures the indentation we computed is what
// is actually used.
let savedWhitespace = "";
if (this.hasNewLine) {
let wsOffset = this.skipWhitespaceBackward(this.result,
this.result.length);
if (this.result[wsOffset] === "\r" || this.result[wsOffset] === "\n") {
savedWhitespace = this.result.substring(wsOffset + 1);
this.result = this.result.substring(0, wsOffset + 1);
}
}
this.result += newIndentation + CSS.escape(name) + ": " +
this.sanitizeText(value, index);
if (priority === "important") {
this.result += " !important";
}
this.result += ";";
if (this.hasNewLine) {
this.result += "\n";
}
this.result += savedWhitespace;
if (this.decl) {
// Still want to copy in the declaration previously at this
// index.
this.completeCopying(this.decl.offsets[0]);
}
}),
/**
* Create a new declaration.
*
* @param {Number} index index of the property in the rule.
* @param {String} name name of the new property
* @param {String} value value of the new property
* @param {String} priority priority of the new property; either
* the empty string or "important"
*/
createProperty: function (index, name, value, priority) {
this.editPromise = this.internalCreateProperty(index, name, value,
priority);
},
/**
* Set a declaration's value.
*
* @param {Number} index index of the property in the rule.
* This can be -1 in the case where
* the rule does not support setRuleText;
* generally for setting properties
* on an element's style.
* @param {String} name the property's name
* @param {String} value the property's value
* @param {String} priority the property's priority, either the empty
* string or "important"
*/
setProperty: function (index, name, value, priority) {
this.completeInitialization(index);
// We might see a "set" on a previously non-existent property; in
// that case, act like "create".
if (!this.decl) {
this.createProperty(index, name, value, priority);
return;
}
// Note that this assumes that "set" never operates on disabled
// properties.
this.result += this.inputString.substring(this.decl.offsets[0],
this.decl.colonOffsets[1]) +
this.sanitizeText(value, index);
if (priority === "important") {
this.result += " !important";
}
this.result += ";";
this.completeCopying(this.decl.offsets[1]);
},
/**
* Remove a declaration.
*
* @param {Number} index index of the property in the rule.
* @param {String} name the name of the property to remove
*/
removeProperty: function (index, name) {
this.completeInitialization(index);
// If asked to remove a property that does not exist, bail out.
if (!this.decl) {
return;
}
let copyOffset = this.decl.offsets[1];
// Maybe removing this rule left us with a completely blank
// line. In this case, we'll delete the whole thing. We only
// bother with this if we're looking at sources that already
// have a newline somewhere.
if (this.hasNewLine) {
let nlOffset = this.skipWhitespaceBackward(this.result,
this.decl.offsets[0]);
if (nlOffset < 0 || this.result[nlOffset] === "\r" ||
this.result[nlOffset] === "\n") {
let trailingText = this.inputString.substring(copyOffset);
let match = BLANK_LINE_RX.exec(trailingText);
if (match) {
this.result = this.result.substring(0, nlOffset + 1);
copyOffset += match[0].length;
}
}
}
this.completeCopying(copyOffset);
},
/**
* An internal function to copy any trailing text to the output
* string.
*
* @param {Number} copyOffset Offset into |inputString| of the
* final text to copy to the output string.
*/
completeCopying: function (copyOffset) {
// Add the trailing text.
this.result += this.inputString.substring(copyOffset);
},
/**
* Apply the modifications in this object to the associated rule.
*
* @return {Promise} A promise which will be resolved when the modifications
* are complete.
*/
apply: function () {
return promise.resolve(this.editPromise).then(() => {
return this.rule.setRuleText(this.result);
});
},
/**
* Get the result of the rewriting. This is used for testing.
*
* @return {object} an object of the form {changed: object, text: string}
* |changed| is an object where each key is
* the index of a property whose value had to be
* rewritten during the sanitization process, and
* whose value is the new text of the property.
* |text| is the rewritten text of the rule.
*/
getResult: function () {
return {changed: this.changedDeclarations, text: this.result};
},
};
/**
* Returns an array of the parsed CSS selector value and type given a string.
*
* The components making up the CSS selector can be extracted into 3 different
* types: element, attribute and pseudoclass. The object that is appended to
* the returned array contains the value related to one of the 3 types described
* along with the actual type.
*
* The following are the 3 types that can be returned in the object signature:
* (1) SELECTOR_ATTRIBUTE
* (2) SELECTOR_ELEMENT
* (3) SELECTOR_PSEUDO_CLASS
*
* @param {String} value
* The CSS selector text.
* @return {Array} an array of objects with the following signature:
* [{ "value": string, "type": integer }, ...]
*/
function parsePseudoClassesAndAttributes(value) {
if (!value) {
throw new Error("empty input string");
}
let tokens = cssTokenizer(value);
let result = [];
let current = "";
let functionCount = 0;
let hasAttribute = false;
let hasColon = false;
for (let token of tokens) {
if (token.tokenType === "ident") {
current += value.substring(token.startOffset, token.endOffset);
if (hasColon && !functionCount) {
if (current) {
result.push({ value: current, type: SELECTOR_PSEUDO_CLASS });
}
current = "";
hasColon = false;
}
} else if (token.tokenType === "symbol" && token.text === ":") {
if (!hasColon) {
if (current) {
result.push({ value: current, type: SELECTOR_ELEMENT });
}
current = "";
hasColon = true;
}
current += token.text;
} else if (token.tokenType === "function") {
current += value.substring(token.startOffset, token.endOffset);
functionCount++;
} else if (token.tokenType === "symbol" && token.text === ")") {
current += token.text;
if (hasColon && functionCount == 1) {
if (current) {
result.push({ value: current, type: SELECTOR_PSEUDO_CLASS });
}
current = "";
functionCount--;
hasColon = false;
} else {
functionCount--;
}
} else if (token.tokenType === "symbol" && token.text === "[") {
if (!hasAttribute && !functionCount) {
if (current) {
result.push({ value: current, type: SELECTOR_ELEMENT });
}
current = "";
hasAttribute = true;
}
current += token.text;
} else if (token.tokenType === "symbol" && token.text === "]") {
current += token.text;
if (hasAttribute && !functionCount) {
if (current) {
result.push({ value: current, type: SELECTOR_ATTRIBUTE });
}
current = "";
hasAttribute = false;
}
} else {
current += value.substring(token.startOffset, token.endOffset);
}
}
if (current) {
result.push({ value: current, type: SELECTOR_ELEMENT });
}
return result;
}
/**
* Expects a single CSS value to be passed as the input and parses the value
* and priority.
*
* @param {Function} isCssPropertyKnown
* A function to check if the CSS property is known. This is either an
* internal server function or from the CssPropertiesFront.
* that are supported by the server.
* @param {String} value
* The value from the text editor.
* @return {Object} an object with 'value' and 'priority' properties.
*/
function parseSingleValue(isCssPropertyKnown, value) {
let declaration = parseDeclarations(isCssPropertyKnown,
"a: " + value + ";")[0];
return {
value: declaration ? declaration.value : "",
priority: declaration ? declaration.priority : ""
};
}
exports.cssTokenizer = cssTokenizer;
exports.cssTokenizerWithLineColumn = cssTokenizerWithLineColumn;
exports.escapeCSSComment = escapeCSSComment;
// unescapeCSSComment is exported for testing.
exports._unescapeCSSComment = unescapeCSSComment;
exports.parseDeclarations = parseDeclarations;
// parseCommentDeclarations is exported for testing.
exports._parseCommentDeclarations = parseCommentDeclarations;
exports.RuleRewriter = RuleRewriter;
exports.parsePseudoClassesAndAttributes = parsePseudoClassesAndAttributes;
exports.parseSingleValue = parseSingleValue;