t.js as a class

t.class.js

class t {
    blockregex = /\{\{(([@!]?)(.+?))\}\}(([\s\S]+?)(\{\{:\1\}\}([\s\S]+?))?)\{\{\/\1\}\}/g;
    valregex = /\{\{([=%])(.+?)\}\}/g;

    constructor(template) {
        this._t = template;
    }
    scrub(val) {
        return val.replace(/"/g, """);
    }
    get_value(vars, key) {
        var parts = key.split('.');
        while (parts.length) {
            if (!(parts[0] in vars)) {
                return false;
            }
            vars = vars[parts.shift()];
        }
        return vars;
    }

    _render(fragment, vars) {
        return fragment
            .replace(this.blockregex, function (_, __, meta, key, inner, if_true, has_else, if_false) {

                var val = this.get_value(vars, key), temp = "", i;

                if (!val) {

                    // handle if not
                    if (meta == '!') {
                        return this._render(inner, vars);
                    }
                    // check for else
                    if (has_else) {
                        return this._render(if_false, vars);
                    }

                    return "";
                }

                // regular if
                if (!meta) {
                    return this._render(if_true, vars);
                }

                // process array/obj iteration
                if (meta == '@') {
                    // store any previous vars
                    // reuse existing vars
                    _ = vars._key;
                    __ = vars._val;
                    for (i in val) {
                        if (val.hasOwnProperty(i)) {
                            vars._key = i;
                            vars._val = val[i];
                            temp += render(inner, vars);
                        }
                    }
                    vars._key = _;
                    vars._val = __;
                    return temp;
                }

            })
            .replace(this.valregex, function (_, meta, key) {
                var val = this.get_value(vars, key);

                if (val || val === 0) {
                    return meta == '%' ? this.scrub(val) : val;
                }
                return "";
            });
    }
    render(vars) {
        return this._render(this._t, vars);
    }
}