Splitting a string only when the delimiter is not enclosed in quotation marks

Question

I need to write a split function in JavaScript that breaks a string into an array with a comma ... but the comma should not be enclosed in quotation marks ( ' and " ).

Here are three examples and how the result (array) should be:

 "peanut, butter, jelly" -> ["peanut", "butter", "jelly"] "peanut, 'butter, bread', 'jelly'" -> ["peanut", "butter, bread", "jelly"] 'peanut, "butter, bread", "jelly"' -> ["peanut", 'butter, bread', "jelly"] 

The reason I cannot use the JavaScript split method is because it also breaks when the delimiter is enclosed in quotation marks.

How to do this, maybe with regular expression?

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As for the context, I will use it to separate the arguments passed from the third element of the third argument passed to the function you are creating, with the jQuery $.expr[':'] extension. Usually, the name assigned to this parameter is called meta , which is an array containing specific information about this filter.

In any case, the third element of this array is a string containing the parameters that are passed with the filter; and since the parameters are in string format, I should be able to split them correctly for parsing.

Answer 1

What you are asking for is essentially a Javascript CSV parser. Do a Google search on the "Javascript CSV Parser" and you will get many hits, many of which have a complete script. See Also Javascript for Parsing CSV Data

Answer 2

 var str = 'text, foo, "haha, dude", bar'; var fragments = str.match(/[az]+|(['"]).*?\1/g); 

Even better (supports strings " or ' inside strings):

 var str = 'text_123 space, foo, "text, here\", dude", bar, \'one, two\', blob'; var fragments = str.match(/[^"', ][^"',]+[^"', ]|(["'])(?:[^\1\\\\]|\\\\.)*\1/g); // Result: 0: text_123 space 1: foo 2: "text, here\", dude" 3: bar 4: 'one, two' 5: blob 

Answer 3

Well, I already have a jackhammer of a written solution (the general code is written for something else), so just for kicks.,.

 function Lexer () { this.setIndex = false; this.useNew = false; for (var i = 0; i < arguments.length; ++i) { var arg = arguments [i]; if (arg === Lexer.USE_NEW) { this.useNew = true; } else if (arg === Lexer.SET_INDEX) { this.setIndex = Lexer.DEFAULT_INDEX; } else if (arg instanceof Lexer.SET_INDEX) { this.setIndex = arg.indexProp; } } this.rules = []; this.errorLexeme = null; } Lexer.NULL_LEXEME = {}; Lexer.ERROR_LEXEME = { toString: function () { return "[object Lexer.ERROR_LEXEME]"; } }; Lexer.DEFAULT_INDEX = "index"; Lexer.USE_NEW = {}; Lexer.SET_INDEX = function (indexProp) { if ( !(this instanceof arguments.callee)) { return new arguments.callee.apply (this, arguments); } if (indexProp === undefined) { indexProp = Lexer.DEFAULT_INDEX; } this.indexProp = indexProp; }; (function () { var New = (function () { var fs = []; return function () { var f = fs [arguments.length]; if (f) { return f.apply (this, arguments); } var argStrs = []; for (var i = 0; i < arguments.length; ++i) { argStrs.push ("a[" + i + "]"); } f = new Function ("var a=arguments;return new this(" + argStrs.join () + ");"); if (arguments.length < 100) { fs [arguments.length] = f; } return f.apply (this, arguments); }; }) (); var flagMap = [ ["global", "g"] , ["ignoreCase", "i"] , ["multiline", "m"] , ["sticky", "y"] ]; function getFlags (regex) { var flags = ""; for (var i = 0; i < flagMap.length; ++i) { if (regex [flagMap [i] [0]]) { flags += flagMap [i] [1]; } } return flags; } function not (x) { return function (y) { return x !== y; }; } function Rule (regex, lexeme) { if (!regex.global) { var flags = "g" + getFlags (regex); regex = new RegExp (regex.source, flags); } this.regex = regex; this.lexeme = lexeme; } Lexer.prototype = { constructor: Lexer , addRule: function (regex, lexeme) { var rule = new Rule (regex, lexeme); this.rules.push (rule); } , setErrorLexeme: function (lexeme) { this.errorLexeme = lexeme; } , runLexeme: function (lexeme, exec) { if (typeof lexeme !== "function") { return lexeme; } var args = exec.concat (exec.index, exec.input); if (this.useNew) { return New.apply (lexeme, args); } return lexeme.apply (null, args); } , lex: function (str) { var index = 0; var lexemes = []; if (this.setIndex) { lexemes.push = function () { for (var i = 0; i < arguments.length; ++i) { if (arguments [i]) { arguments [i] [this.setIndex] = index; } } return Array.prototype.push.apply (this, arguments); }; } while (index < str.length) { var bestExec = null; var bestRule = null; for (var i = 0; i < this.rules.length; ++i) { var rule = this.rules [i]; rule.regex.lastIndex = index; var exec = rule.regex.exec (str); if (exec) { var doUpdate = !bestExec || (exec.index < bestExec.index) || (exec.index === bestExec.index && exec [0].length > bestExec [0].length) ; if (doUpdate) { bestExec = exec; bestRule = rule; } } } if (!bestExec) { if (this.errorLexeme) { lexemes.push (this.errorLexeme); return lexemes.filter (not (Lexer.NULL_LEXEME)); } ++index; } else { if (this.errorLexeme && index !== bestExec.index) { lexemes.push (this.errorLexeme); } var lexeme = this.runLexeme (bestRule.lexeme, bestExec); lexemes.push (lexeme); } index = bestRule.regex.lastIndex; } return lexemes.filter (not (Lexer.NULL_LEXEME)); } }; }) (); if (!Array.prototype.filter) { Array.prototype.filter = function (fun) { var len = this.length >>> 0; var res = []; var thisp = arguments [1]; for (var i = 0; i < len; ++i) { if (i in this) { var val = this [i]; if (fun.call (thisp, val, i, this)) { res.push (val); } } } return res; }; } 

Now, to use the code for your problem:

 function trim (str) { str = str.replace (/^\s+/, ""); str = str.replace (/\s+$/, ""); return str; } var splitter = new Lexer (); splitter.setErrorLexeme (Lexer.ERROR_LEXEME); splitter.addRule (/[^,"]*"[^"]*"[^,"]*/g, trim); splitter.addRule (/[^,']*'[^']*'[^,']*/g, trim); splitter.addRule (/[^,"']+/g, trim); splitter.addRule (/,/g, Lexer.NULL_LEXEME); var strs = [ "peanut, butter, jelly" , "peanut, 'butter, bread', 'jelly'" , 'peanut, "butter, bread", "jelly"' ]; // NOTE: I'm lazy here, so I'm using Array.prototype.map, // which isn't supported in all browsers. var splitStrs = strs.map (function (str) { return splitter.lex (str); }); 

Answer 4

If you can control the input to ensure that the string is enclosed in double quotes " and that all elements containing the string are enclosed in single quotation marks ' and that no element can CONTAIN a single -quote, then you can split by , ' If you CANNOT control the input, then using a regular expression to sort / filter / split the input will be about as useful as using a regular expression to match with xhtml (see RegEx match open tags except self-tuning XHTM tags L )