arTemplate解析语法

模板解析语法

defaults.parser = function (code, options) {

    // var match = code.match(/([\w\$]*)(\b.*)/);

    // var key = match[1];

    // var args = match[2];

    // var split = args.split(' ');

    // split.shift();

    code = code.replace(/^\s/, '');

    var split = code.split(' ');

    var key = split.shift();

    var args = split.join(' ');

    switch (key) {

        case 'if':

            code = 'if(' + args + '){';

            break;

        case 'else':

            if (split.shift() === 'if') {

                split = ' if(' + split.join(' ') + ')';

            } else {

                split = '';

            }

            code = '}else' + split + '{';

            break;

        case '/if':

            code = '}';

            break;

        case 'each':

            var object = split[0] || '$data';

            var as     = split[1] || 'as';

            var value  = split[2] || '$value';

            var index  = split[3] || '$index';

            var param   = value + ',' + index;

            if (as !== 'as') {

                object = '[]';

            }

            code =  '$each(' + object + ',function(' + param + '){';

            break;

        case '/each':

            code = '});';

            break;

        case 'echo':

            code = 'print(' + args + ');';

            break;

        case 'print':

        case 'include':

            code = key + '(' + split.join(',') + ');';

            break;

        default:

            // 过滤器（辅助方法）

            // {{value | filterA:'abcd' | filterB}}

            // >>> $helpers.filterB($helpers.filterA(value, 'abcd'))

            // TODO: {{ddd||aaa}} 不包含空格

            if (/^\s*\|\s*[\w\$]/.test(args)) {

                var escape = true;

                // {{#value | link}}

                if (code.indexOf('#') === 0) {

                    code = code.substr(1);

                    escape = false;

                }

                var i = 0;

                var array = code.split('|');

                var len = array.length;

                var val = array[i++];

                for (; i < len; i ++) {

                    val = filtered(val, array[i]);

                }

                code = (escape ? '=' : '=#') + val;

            // 即将弃用 {{helperName value}}

            } else if (template.helpers[key]) {

                code = '=#' + key + '(' + split.join(',') + ');';

            // 内容直接输出 {{value}}

            } else {

                code = '=' + code;

            }

            break;

    }

    return code;

};