写一个单例构造的对话框

摘要：前言项目中，当需要用户处理事务，又不希望跳转页面以致打断工作流程时，我们会经常使用到对话框去承载相应的操作。虽然用得多，但是很多人其实并不知道怎么去写。饶有兴趣，自己尝试写了一个。

项目中，当需要用户处理事务，又不希望跳转页面以致打断工作流程时，我们会经常使用到对话框去承载相应的操作。虽然用得多，但是很多人其实并不知道怎么去写。饶有兴趣，自己尝试写了一个。

对话框全局中使用一个就够了，为了防止生成多个对话框，我们使用单例构造

var Dialog = (function () {
    var instance;
    return function (options) {
        if (!instance) {
            instance = new Modal(options);
        }
        return instance;
    }
})()

这里主要运用到了闭包中的特性

modal.js代码

var Dialog = (function () {
    var instance;
    return function (options) {
        if (!instance) {
            instance = new Modal(options);
        }
        return instance;
    }
})()

class Modal {
    constructor(options) {
        //默认属性
        this.initOptions = {
            title: "标题",
            maskClosable: true,
            header: true,
            footer: true,
            closable: true,
            okText: "确 定",
            cancelText: "取 消",
            destroyOnClose: false,
            keyboard: true,
            zIndex: 1000,
            width: 500,
            afterClose: null
        }
        this.options = Object.assign({}, this.initOptions, options);

        this.instance = document.createElement("div");//节点实例，因为只需要一个模态框，这里设置节点就可以了
        this.mounted = false; //是否挂载在节点上
    }

    //处理模态框的点击事件
    _modalClick(e) {
        var className = e.target.className;
        //匹配类名，例如 带有 class="modal-close" 的元素点击可以关闭模态框
        if (new RegExp("(s|^)modal-close(s|$)").test(className)) {
            this.cancel();   //关闭模态框
        } else if (new RegExp("(s|^)modal-onOk(s|$)").test(className)) {
            this.onOk();     //执行确定按钮的回调
        } else if (new RegExp("(s|^)modal-container(s|$)").test(className)) {
            this.outSideClick(); //模态框外的点击
        }
    }

    //处理键盘ESC关闭
    _escClose(e) {
        var code = e.keyCode;
        if (code === 27) {
            this.cancel();
        }
    }

    //渲染模态框节点
    render() {
        var modal = this.instance;
        modal.style.zIndex = this.options.zIndex;
        modal.className = "modal-container";
        var closeIcon = this.options.closable ? `X` : "";
        var header = this.options.header ?
            (this.options.header === true ?
                `
${this.options.title}
                                    ${closeIcon}
                                
` :
                this.options.header) :
            "";
        var footer = this.options.footer ?
            (this.options.footer === true ?
                `

                                ${this.options.cancelText}
                                ${this.options.okText}
                            
` :
                this.options.footer) :
            "";
        modal.innerHTML = `

                                ${header}
                                
${this.options.content}
                                ${footer}
                            
`;
    }


    //蒙层点击关闭
    outSideClick() {
        if (this.options.maskClosable) {
            this.close();
        }
    }

    //处理监听
    listen() {
        this._modalClick = this._modalClick.bind(this);
        this.instance.addEventListener("click", this._modalClick);
        
        if(this.options.keyboard){
            this._escClose = this._escClose.bind(this);
            window.addEventListener("keyup", this._escClose);
        }
    }

    cancel(){
        if(typeof this.options.onCancel === "function"){
            this.options.onCancel();
        }
        this.close();
    }

    //点击确定回调
    onOk() {
        this
            .options
            .onOkFn();
        this.close();
    }


    /****************** 提供的方法  ********************* */
    //设置属性
    set(options) {
        Object.assign(this.options, options)
        this.render()
    }

    //打开模态框
    open() {
        var modal = this.instance;
        //实例如果没挂载
        if (!this.mounted) {
            this.mounted = true;
            this.render();
            document.body.appendChild(modal);
            this.listen()
        }
        removeClass(modal, "close");
        addClass(modal, "open");
    }

    //关闭模态框
    close() {
        var modal = this.instance
        removeClass(modal, "open");
        addClass(modal, "close");
        if (this.options.destroyOnClose === true) {
            this.destroy();
        }
        if (typeof this.options.afterClose === "function") {
            var afterClose = this.options.afterClose.bind(this);
            setTimeout(afterClose, 0);
        }
    }
    //从节点上移除模态框
    destroy() {
        this.instance.removeEventListener("click", this._modalClick);//移除click监听
        window.removeEventListener("keyup", this._escClose);//移除keyup监听
        document.body.removeChild(this.instance);//移除模态框节点
        this.mounted = false;
    }

}

function hasClass(elements, cName) {
    return !!elements
        .className
        .match(new RegExp("(s|^)" + cName + "(s|$)"));
};
function addClass(elements, cName) {
    if (!hasClass(elements, cName)) {
        elements.className += " " + cName;
    };
};
function removeClass(elements, cName) {
    if (hasClass(elements, cName)) {
        elements.className = elements
            .className
            .replace(new RegExp("(s|^)" + cName + "(s|$)"), "");
    };
};

modal.css

@keyframes openAnimate {
    0% {
        opacity: 0;
    }
    100%{
        opacity: 1;
    }
}

.open{
    display: block !important;
    animation: openAnimate .8s;
}
.close{
    display: none;
}
.modal-container {
    position: fixed;
    top: 0;
    right: 0;
    left: 0;
    bottom: 0;
    background-color: #373737;
    background-color: rgba(0,0,0,.65);
    margin: auto;
    filter: alpha(opacity=50);
    text-align: center;
    font-size: 0;
    white-space: nowrap;
    overflow: auto;
    display: none;
}

.modal-container:after {
    content: "";
    display: inline-block;
    height: 100%;
    vertical-align: middle;
}

.modal {
    display: inline-block;
    vertical-align: middle;
    text-align: left;
    font-size: 14px;
    background-color: #fff;
    border: 0;
    border-radius: 4px;
    background-clip: padding-box;
    box-shadow: 0 4px 12px rgba(0,0,0,.15);
}

.modal-header{
    padding: 16px 24px;
    border-radius: 4px 4px 0 0;
    background: #fff;
    color: rgba(0,0,0,.65);
    border-bottom: 1px solid #e8e8e8;
}
.modal-close{
    float: right;
    cursor: pointer;
}
.modal-content{
    padding: 24px;
    font-size: 14px;
    line-height: 1.5;
    word-wrap: break-word;
    min-height: 200px;
}

.modal-footer {
    border-top: 1px solid #e8e8e8;
    padding: 10px 16px;
    text-align: right;
    border-radius: 0 0 4px 4px;
}

.modal-btn{
    line-height: 32px;
    display: inline-block;
    font-weight: 400;
    text-align: center;
    touch-action: manipulation;
    cursor: pointer;
    background-image: none;
    border: 1px solid transparent;
    white-space: nowrap;
    padding: 0 15px;
    font-size: 14px;
    border-radius: 4px;
    height: 32px;
    user-select: none;
    transition: all .3s cubic-bezier(.645,.045,.355,1);
    position: relative;
    color: rgba(0,0,0,.65);
    background-color: #fff;
    border-color: #d9d9d9;
    cursor: pointer;
}

.modal-btn-primary{
    color: #fff;
    background-color: #1890ff;
    border-color: #1890ff;
}

    
        
        
        
        
        
    

    
        1
        2
        3
        
        
    

index.js

var config = {
    title: "模态框标题",
    content: "",
    header: true,
    footer: true,
    destroyOnClose: true,
    onOkFn: function () {
        alert("提交成功")
    },
    afterClose: function(){
        alert("已经关闭")
    }
}
var modal = new Dialog(config);
var openBtns = document.querySelectorAll(".open");
openBtns.forEach(function (item, index) {
    item.onclick = function () {
        var option = {
            content: "这是第" + (index + 1) + "个"
        }
        modal.set(option)
        modal.open();
    }

})