ExtJS中格式化json显示

,  {
    xtype: 'button',
    text: '格式化',
    iconCls: 'icon-edit',
    colspan: 2,
    width: 100,
    margin: "-23 0 0 70",
    listeners: {
        'click': {
            fn: this.formatJson,
            scope: this
        }
    }
}

formatJson : function(options) {
    var dataform = this.down('dataform');
    var json=dataform.down("[name='actConfigValue']").getValue();
    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;
    });
    dataform.down("[name='actConfigValue']").setValue(formatted);
    // return formatted;
},