如何使用js来实现多行溢出隐藏功能

//调用方式:k('#p').ellipsistoText(3), k('#p').ellipsistoLine(2), k('#p').restoretoLine(), k('#p').restoretoText()
(function () {
    var k = function (selector) {
        return new F(selector)
    }
    var F = function (selector) {
        this.ele = document.querySelector(selector);
        if (!this.ele.ori_height) {
            this.ele.ori_height = this.ele.offsetHeight; //用于保存原始高度
        }
        if (!this.ele.ori_html) {
            this.ele.ori_html = this.ele.innerHTML; //用于保存原始内容
        }
    }
    F.prototype = {
        init: function () {
            this.ele.style.height = this.ele.ori_height;
            this.ele.innerHTML = this.ele.ori_html;
        },
        ellipsistoLine: function (l) {
            this.init();
            this.ele.style.cssText = 'overflow: hidden; height: ' + parseInt(window.getComputedStyle(this.ele)['line-height']) * l + 'px';
        },
        ellipsistoText: function (t) {
            this.init();
            var len = (this.ele.ori_html).length * (1/t);
            this.ele.innerHTML = this.ele.ori_html.substr(0, len);
        },
        restoretoLine: function () {
            this.ele.style.height = this.ele.ori_height + 'px';
        },
        restoretoText: function () {
            this.ele.innerHTML = this.ele.ori_html;
        }
    }
    window.k = k;
})(window)