js/javascript format json(js/javascript 格式化json字符串)

// format json obj string
function format_json(txt, compress) {
    var indentChar = '    ';
    if (/^\s*$/.test(txt)) {
        //alert('txt is empty');   
        return '';
    }
    try {
        var data = eval('(' + txt + ')');
        txt = txt.replace(new RegExp("\"{","gm"), "{").replace(new RegExp("}\"","gm"), "}");
        txt = txt.replace(new RegExp("\\\\\\\"","gm"), "\"");
        txt = txt.replace(new RegExp("\\\\\\\"","gm"), "\"");
        txt = txt.replace(new RegExp("\\\\\\\"","gm"), "\"");

        txt = txt.replace(new RegExp(" ","gm"), "");

//        console.log(txt);
        data = eval('(' + txt + ')');
    } catch (e) {
        //alert('txt format error: '+e.description,'err');   
        return txt;
    }
    ;
    var draw = [], last = false, This = this, line = compress ? ''
            : '<br/>', nodeCount = 0, maxDepth = 0;
    var notify = function(name, value, isLast, indent, formObj) {
        if (indent == 0) {
            //draw.push('<table>');
        }
        nodeCount++;
        for (var i = 0, tab = ''; i < indent; i++)
            tab += indentChar;
        tab = compress ? '' : tab;
        maxDepth = ++indent;
        if (value && value.constructor == Array) {
            draw.push(tab + (formObj ? ('"' + name + '":') : '') + '['
                    + line);
            for (var i = 0; i < value.length; i++)
                notify(i, value[i], i == value.length - 1, indent,
                        false);
            draw.push(tab + ']' + (isLast ? line : (',' + line)));
        } else if (value && typeof value == 'object') {
            draw.push(tab + (formObj ? ('"' + name + '":') : '') + '{'
                    + line);
            var len = 0, i = 0;
            for ( var key in value)
                len++;
            for ( var key in value)
                notify(key, value[key], ++i == len, indent, true);
            draw.push(tab + '}' + (isLast ? line : (',' + line)));
        } else {
            if (typeof value == 'string')
                value = '"' + value + '"';
            draw.push(tab + (formObj ? ('"' + name + '":') : '')
                    + value + (isLast ? '' : ',') + line);
        }
        ;
    };
    var isLast = true, indent = 0;
    
    notify('', data, isLast, indent, false);
    return draw.join('');
}

function addIndentBlank(indent) {
    indentChar = '&nbsp;&nbsp;&nbsp;&nbsp;';
    var ret = "";
    for (var i = 0; i < indent; i++) {
        ret += indentChar;
    }
    return ret;
}

// format all string
function format_str(txt) {
    if (/^\s*$/.test(txt)) {
        //alert('txt is empty');   
        return '';
    }
    try {
        //var data = eval('(' + txt + ')');
        txt = txt.replace(new RegExp("\"{","gm"), "{").replace(new RegExp("}\"","gm"), "}");    // "{->{   }"->}
        txt = txt.replace(new RegExp("\\\\\\\"","gm"), "\"");    // \"->"
        txt = txt.replace(new RegExp("\\\\\\\"","gm"), "\"");
        txt = txt.replace(new RegExp("\\\\\\\"","gm"), "\"");
        
        txt = txt.replace(new RegExp("\\\\\\\\r","gm"), "\\r");
        txt = txt.replace(new RegExp("\\\\\\\\n","gm"), "\\n");
        txt = txt.replace(new RegExp("\\\\\\\\r","gm"), "\\r");
        txt = txt.replace(new RegExp("\\\\\\\\n","gm"), "\\n");
        txt = txt.replace(new RegExp("\\\\\\\\r","gm"), "\\r");
        txt = txt.replace(new RegExp("\\\\\\\\n","gm"), "\\n");

        //txt = txt.replace(new RegExp("&nbsp;","gm"), "");

        var draw = [];
        var line = "<br/>";
        var indent = 0;
        var quoteCount = 0;
        var quoteOddEven = 0;    // Even count quote(") to deal, Odd is string
        var containLeftBrace = false;
        var preChar = '';
        var nextChar = '';
        for (var i = 0; i < txt.length; i++) {
             current = txt.charAt(i);
             try {
                 nextChar = txt.charAt(i + 1);
             } catch (e) {
                 console.log(e);
             }
             switch (current) {
                 case '{':
                     containLeftBrace = true;
                 case '[': {
                     if (preChar == '\"') {
                         draw.push(current);
                         break;
                     }
                     if (quoteOddEven == 0) {
                         ++indent;
                         draw.push(current);
                         draw.push(line);
                         draw.push(addIndentBlank(indent));
                         break;
                     } else {
                         draw.push(current);
                         break;
                     }
                 }
                 case '}':
                 case ']': {
                     if (nextChar == '\"') {
                         draw.push(current);
                         break;
                     }
                     if (quoteOddEven == 0) {
                         --indent;
                         draw.push(line);
                         draw.push(addIndentBlank(indent));
                         draw.push(current);
                         break;
                     } else {
                         draw.push(current);
                         break;
                     }
                 }
                 case ',': {
                     if (quoteOddEven == 0 && quoteCount > 0 && containLeftBrace) {
                         draw.push(current);
                         draw.push(line);
                         draw.push(addIndentBlank(indent));
                         break;
                     } else {
                         draw.push(current);
                         break;
                     }
                 }
                 case '\\': {
                     try {
                         next1 = txt.charAt(i+1);
                         next2 = txt.charAt(i+2);
                         next3 = txt.charAt(i+3);
//                         console.log(current + next1 + next2 + next3);
                         if ((next1 + "") == "r" && (current + next1 + next2 + next3) == "\\r\\n") {
                             draw.push(line);
                             draw.push(addIndentBlank(indent + 1));
                             i = i+3;
                         }
                     } catch(e) {
                         console.log(e);
                     }
                     break;
                 }
                 case '\"': {
                     quoteCount = quoteCount + 1;
                     quoteOddEven = (quoteOddEven + 1) % 2;
                     draw.push(current);
                     break;
                 }
                 default: {
                     draw.push(current);
                 }
             }
             preChar = current;
        }

//        console.log('draw: ' + draw.join(''));
    } catch (e) {
//        alert('txt format error: '+e,'err');   
        return txt;
    }
    ;
    return draw.join('');
}