纯JS实现待办事项APP

            
            * {
    box-sizing: border-box;
    font-weight: 300;
    margin: 0;
    padding: 0;
    font-family: 'Quicksand', sans-serif;
}
html {
    width: 100%;
    min-height: 100%;

}
body {
    background-color: #CAD6E5;
    width: 100%;
    min-height: 100%;
}
.wrapper {
    margin: 0 auto;
    padding: 100px 0 100px 0;
    width: 100%;
    height: 100%;
}
.main-container {
    background-color:#ffffff;
    width: 400px;
    height:auto;
    margin:auto;
    min-height: 100%;
    margin: 0 auto;  
    box-shadow: 0px 10px 50px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    border-radius: 8px;
}
.clearfix::after {
    content: "";
    display: table;
    clear: both;
}

body {
    color: #555;
    font-size: 16px;
    position: relative;
    height: 100vh;
    font-weight: 400;
}

.right { float: right; }
.red { color: #FF5049 !important; }
.red-focus:focus { border: 1px solid #FF5049 !important; }

/**********************************************
*** TOP PART
**********************************************/

.top {
    height: 150px;
    background: linear-gradient(to bottom, rgba(131, 56, 236, 0.8) 0%, rgba(131, 56, 236, 0.6) 100%), url(https://s7.postimg.org/yap5ueygr/back.png);
    position: relative;
    border-radius: 0 0 100% 100%;
    width: 140%;
    margin-left: -20%;
    z-index: 2;
    margin-bottom: 20px;
}
/* .top::before {
    content: '';
    background-color: #f7f7f7;
    height: 200px;
    width: 100%;
    border-radius: 0;
    position: absolute;
    z-index: 0;
} */

.title {
    position: absolute;
    width: 350px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: #fff;
}
.title h1 {
    font-size: 26px;
    text-align: center;
    font-weight: 300;
    margin-bottom: 10px;
    font-family: 'Montserrat Alternates', Arial, sans-serif;
}
.title h2, .title h2 span{
    font-size: 18px;
    text-align: center;
    margin-bottom: 10px;
    font-weight: 300;
    text-transform: none;
    
}


/**********************************************
*** BOTTOM PART
**********************************************/

/***** FORM *****/
.add {
    padding: 14px;
    background-color: #f7f7f7;
    display: none;
    -webkit-transition: all 250ms ease;
    -o-transition: all 250ms ease;
    transition: all 250ms ease;
    height: 100px;
    margin-top: -40px;
    z-index: 1;
}

.add__container {
    margin: 0 auto;
    text-align: center;
    position: relative;
    top: 20px;
}

.add__description {
    background-color: #f7f7f7;
    font-family: inherit;
    font-size: 20px;
    padding: 20px 15px 12px;
    transition: border 0.3s;
    width: 100%;
    border:none;
    color: #939CA7;
}

.add__btn {
    font-size: 40px;
    border: none;
    color: #ffffff;
    cursor: pointer;
    font-family: 'Montserrat Alternates', Arial, sans-serif;
    line-height: 1.1;
    margin-left: 10px;
    background-color: #FF006E;
    border-radius:100%;
    height: 50px;
    width: 50px;
    bottom: -22px;
    position: absolute;
    left:0;
    right:0;
    margin: 0 auto;
    box-shadow: 0px 10px 50px rgba(0, 0, 0, 0.1);
    z-index: 2;
}
.add__btn:active { transform: translateY(2px); }
.add__description:focus {
    outline: none;
    border: none;
}
.add__btn:focus { outline: none; }

/***** LISTS *****/
.container {
    width: 100%;
    margin:auto;
    padding:10px;
}

.item {
    padding: 15px;
    width:170px;
    height:170px;
    border-radius:8px;
    font-size:18px;
    color:#fff;
    float: left;
    margin:10px;
    position: relative;
    box-shadow: 0px 10px 30px rgba(0, 0, 0, 0.2);
}

.item__description {
    word-break: break-all;

}
.income .item__delete--btn {
    color: #fff;
}
.item__delete--btn {
    font-size: 22px;
    background: none;
    border: none;
    cursor: pointer;
    display: inline-block;
    vertical-align: middle;
    line-height: 1;
    display: none;
        position: absolute;
    bottom: 10px;
    right: 12px;
}

.item__delete--btn:focus { outline: none; }
.item__delete--btn:active { transform: translateY(2px); }
.item:hover .item__delete--btn { display: block; }

i {
    color: #ffffff;
}
::-webkit-input-placeholder { /* Chrome/Opera/Safari */
  color: #CAD6E5;
}
::-moz-placeholder { /* Firefox 19+ */
  color: #CAD6E5;
}
:-ms-input-placeholder { /* IE 10+ */
  color: #CAD6E5;
}
:-moz-placeholder { /* Firefox 18- */
  color: #CAD6E5;
}


        

            
            var listController = (function() {
    counter = 3;
    return {
        addItem: function() {
            counter += 1;
        },
        deleteItem: function(item) {
            counter -= 1;
        },
        returnTotalItems: function() {
            return counter;
        },
    }
})();
var UIController = (function() {
    var DOMstrings = {
        inputDescription: '.add__description',
        inputBtn: '.add__btn',
        todosContainer: '.todos__list',
        container: '.container',
        totalItems: '.total__items',
        addField: '.add'
    };
    var items = listController.returnTotalItems();
    return {
        getInput: function() {
            return document.querySelector(DOMstrings.inputDescription).value;
        },
        addListItem: function() {
            var items = listController.returnTotalItems();
            var html, newHtml, element;
            element = DOMstrings.todosContainer;
            var colors = ['#FFBE0B', '#FB5607', '#FF006E', '#8338EC', '#3A86FF'];
            var gradients = [
            'linear-gradient(to bottom, rgba(255,190,11, 1) 0%, rgba(255,190,11, 0.8) 100%)', 
            'linear-gradient(to bottom, rgba(251, 86, 7, 1) 0%, rgba(251, 86, 7, 0.8) 100%)',
            'linear-gradient(to bottom, rgba(255,0,110, 1) 0%, rgba(255,0,110, 0.8) 100%)',
            'linear-gradient(to bottom, rgba(131, 56, 236, 1) 0%, rgba(131, 56, 236, 0.8) 100%)',
            'linear-gradient(to bottom, rgba(58,134,255, 1) 0%, rgba(58,134,255, 0.8) 100%)'
             ]
            var random_gradient = gradients[Math.floor(Math.random() * gradients.length)];
            html = '<div class="item" style="%style%"> <div class="item__description">%description%</div><div class="item__delete"><button class="item__delete--btn"><i class="ion-ios-trash-outline"></i></button></div></div>';
            newHtml = html.replace('%description%', document.querySelector(DOMstrings.inputDescription).value);
            newHtml = newHtml.replace('%style%', 'background:' + random_gradient) ;
            document.querySelector(element).insertAdjacentHTML('beforeend', newHtml);
        },
        clearField: function() {
            document.querySelector(DOMstrings.inputDescription).value = '';
            document.querySelector(DOMstrings.inputDescription).focus();
        },
        displayTotalItems: function() {
            var items = listController.returnTotalItems();
            if (items == 0) {
                document.querySelector(DOMstrings.totalItems).textContent = '0';
            } else if (items == 1) {
                document.querySelector(DOMstrings.totalItems).textContent = '1';
            } else {
                document.querySelector(DOMstrings.totalItems).textContent = items;
            }
        },
        displayDate: function () {
            var mydate = new Date();
            var year = mydate.getYear();
            if (year < 1000) {
                year+=1900;
            }
            var day = mydate.getDay();
            var month = mydate.getMonth();
            var daym = mydate.getDate();
            if (daym < 10) {
                daym = "0" + daym;
            }
            var dayarray = ["星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六"];
            var montharray = ["一月", "二月", "三月", "四月", "五月", "六月", "七月", "八月", "九月", "十月", "十一月", "十二月"];
            var today = year +"年" + " "+ montharray[month] + " " + daym + "日 " + dayarray[day];
            document.getElementById('date').innerHTML = today;
        },

        getDOMstrings: function() {
            return DOMstrings;
        },
    };
})();
var controller = (function(listCtrl, UICtrl) {
    var DOM = UICtrl.getDOMstrings();
    var setupEventListeners = function() {
           document.querySelector(DOM.inputBtn).addEventListener('click', showAddField);
        document.addEventListener('keypress', function(e) {
            if (e.keyCode === 13 || e.which === 13) {
                ctrlAddItem();
            };
        });
        document.querySelector(DOM.container).addEventListener('click', ctrlDeleteItem);
    };
    var updateTotalItems = function() {
        listController.returnTotalItems();
        UICtrl.displayBudget(budget);
    };
    var ctrlAddItem = function() {
        if (document.querySelector(DOM.inputDescription).value !== '') {
            listCtrl.addItem();
            UICtrl.addListItem();
            UICtrl.clearField();
            UICtrl.displayTotalItems();
        };
    };
    var showAddField = function() {
        document.querySelector(DOM.addField).style.display = 'block';
        document.querySelector(DOM.inputBtn).addEventListener('click', ctrlAddItem)
        document.querySelector(DOM.inputDescription).focus();
    }
    var ctrlDeleteItem = function(e) {
        var todo = e.target.parentNode.parentNode.parentNode;
        if (e.target && e.target.className === "ion-ios-trash-outline") {
            todo.parentNode.removeChild(todo);
            listCtrl.deleteItem();
        }
        UICtrl.displayTotalItems();
    };
    return {
        init: function() {
            UICtrl.displayTotalItems();
            UICtrl.displayDate();
            setupEventListeners(); 
        },
    };
})(listController, UIController);
controller.init();