javascript格式化json显示

将json对象或者json字符串格式化方便在网页上限制

// Example usage: http://jsfiddle.net/q2gnX/
 
var formatJson = function(json, options) {
	var reg = null,
		formatted = '',
		pad = 0,
		PADDING = '    '; // one can also use '\t' or a different number of spaces
 
	// optional settings
	options = options || {};
	// remove newline where '{' or '[' follows ':'
	options.newlineAfterColonIfBeforeBraceOrBracket = (options.newlineAfterColonIfBeforeBraceOrBracket === true) ? true : false;
	// use a space after a colon
	options.spaceAfterColon = (options.spaceAfterColon === false) ? false : true;
 
	// begin formatting...
	if (typeof json !== 'string') {
		// make sure we start with the JSON as a string
		json = JSON.stringify(json);
	} else {
		// is already a string, so parse and re-stringify in order to remove extra whitespace
		json = JSON.parse(json);
		json = JSON.stringify(json);
	}
 
	// add newline before and after curly braces
	reg = /([\{\}])/g;
	json = json.replace(reg, '\r\n$1\r\n');
 
	// add newline before and after square brackets
	reg = /([\[\]])/g;
	json = json.replace(reg, '\r\n$1\r\n');
 
	// add newline after comma
	reg = /(\,)/g;
	json = json.replace(reg, '$1\r\n');
 
	// remove multiple newlines
	reg = /(\r\n\r\n)/g;
	json = json.replace(reg, '\r\n');
 
	// remove newlines before commas
	reg = /\r\n\,/g;
	json = json.replace(reg, ',');
 
	// optional formatting...
	if (!options.newlineAfterColonIfBeforeBraceOrBracket) {			
		reg = /\:\r\n\{/g;
		json = json.replace(reg, ':{');
		reg = /\:\r\n\[/g;
		json = json.replace(reg, ':[');
	}
	if (options.spaceAfterColon) {			
		reg = /\:/g;
		json = json.replace(reg, ': ');
	}
 
	$.each(json.split('\r\n'), function(index, node) {
		var i = 0,
			indent = 0,
			padding = '';
 
		if (node.match(/\{$/) || node.match(/\[$/)) {
			indent = 1;
		} else if (node.match(/\}/) || node.match(/\]/)) {
			if (pad !== 0) {
				pad -= 1;
			}
		} else {
			indent = 0;
		}
 
		for (i = 0; i < pad; i++) {
			padding += PADDING;
		}
 
		formatted += padding + node + '\r\n';
		pad += indent;
	});
 
	return formatted;
};