摘要：前言項目中，當需要用戶處理事務，又不希望跳轉頁面以致打斷工作流程時，我們會經常使用到對話框去承載相應的操作。雖然用得多，但是很多人其實并不知道怎么去寫。饒有興趣，自己嘗試寫了一個。

項目中，當需要用戶處理事務，又不希望跳轉頁面以致打斷工作流程時，我們會經常使用到對話框去承載相應的操作。雖然用得多，但是很多人其實并不知道怎么去寫。饒有興趣，自己嘗試寫了一個。

對話框全局中使用一個就夠了，為了防止生成多個對話框，我們使用單例構造

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

這里主要運用到了閉包中的特性

modal.js代碼

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

class Modal {
    constructor(options) {
        //默認屬性
        this.initOptions = {
            title: "標題",
            maskClosable: true,
            header: true,
            footer: true,
            closable: true,
            okText: "確 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");//節點實例，因為只需要一個模態框，這里設置節點就可以了
        this.mounted = false; //是否掛載在節點上
    }

    //處理模態框的點擊事件
    _modalClick(e) {
        var className = e.target.className;
        //匹配類名，例如 帶有 class="modal-close" 的元素點擊可以關閉模態框
        if (new RegExp("(s|^)modal-close(s|$)").test(className)) {
            this.cancel();   //關閉模態框
        } else if (new RegExp("(s|^)modal-onOk(s|$)").test(className)) {
            this.onOk();     //執行確定按鈕的回調
        } else if (new RegExp("(s|^)modal-container(s|$)").test(className)) {
            this.outSideClick(); //模態框外的點擊
        }
    }

    //處理鍵盤ESC關閉
    _escClose(e) {
        var code = e.keyCode;
        if (code === 27) {
            this.cancel();
        }
    }

    //渲染模態框節點
    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}
                            
`;
    }


    //蒙層點擊關閉
    outSideClick() {
        if (this.options.maskClosable) {
            this.close();
        }
    }

    //處理監聽
    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();
    }

    //點擊確定回調
    onOk() {
        this
            .options
            .onOkFn();
        this.close();
    }


    /****************** 提供的方法  ********************* */
    //設置屬性
    set(options) {
        Object.assign(this.options, options)
        this.render()
    }

    //打開模態框
    open() {
        var modal = this.instance;
        //實例如果沒掛載
        if (!this.mounted) {
            this.mounted = true;
            this.render();
            document.body.appendChild(modal);
            this.listen()
        }
        removeClass(modal, "close");
        addClass(modal, "open");
    }

    //關閉模態框
    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);
        }
    }
    //從節點上移除模態框
    destroy() {
        this.instance.removeEventListener("click", this._modalClick);//移除click監聽
        window.removeEventListener("keyup", this._escClose);//移除keyup監聽
        document.body.removeChild(this.instance);//移除模態框節點
        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;
}

    
        
        
        
        
        
    

    
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index.js

var config = {
    title: "模態框標題",
    content: "",
    header: true,
    footer: true,
    destroyOnClose: true,
    onOkFn: function () {
        alert("提交成功")
    },
    afterClose: function(){
        alert("已經關閉")
    }
}
var modal = new Dialog(config);
var openBtns = document.querySelectorAll(".open");
openBtns.forEach(function (item, index) {
    item.onclick = function () {
        var option = {
            content: "這是第" + (index + 1) + "個"
        }
        modal.set(option)
        modal.open();
    }

})