《Vue.js实战》章七组件——数字输入框组件

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>数字输入框组件</title>
</head>
<body>
    <div id="app1">
        <input-number v-model="value" :max="10" :min="0"></input-number>
    </div>
    <!-- <div id="app2">
        <input type="text" @change="print" v-model="test">
        <p>{{ test }}</p>
    </div> -->
    <script src="Vue.2.6.10.js"></script>
</body>
<script>
    function isValueNumber(value){
        return (/(^-?[0-9]+.{1}d+$)|(^-?[1-9][0-9]*$)|(^-?0{1}&)/).test(value + '');
        // test()方法，用于检测一个字符串是否符合某个模式
    }

    Vue.component('input-number',{
        template:'
        <div class="input-number">
        <input 
            type="text"
            @focus="keyControl"
            :value="currentValue"
            :step=this.$parent.step
            @change="handleChange">
        <button 
            @click="handleDown" 
            :disabled = "currentValue <= min">-</button>
        <button 
            @click="handleUp" 
            :disabled = "currentValue >= max">+</button>
        </div>',
        props:{
            max:{
                type:Number,
                default:Infinity
            },
            min:{
                type:Number,
                default:-Infinity
            },
            value:{
                type:Number,
                default:0
            },
            step:{
                type:Number,
                default:1
            }
        },
        data() {
            return {
                currentValue:this.value,
                stepNum:this.step
                // stepNum:this.$parent.step
            }
        },
        watch:{
            currentValue:function(val){
                this.$emit('input',val);
                this.$emit('on-change',val);
            },
            value:function(val){
                this.updateValue(val);
            }
        },
        methods: {
            keyControl:function(){
                var _this = this;
                document.onkeydown = function(e){
                if(document.getElementsByTagName('input')){
                    if(e.keyCode == 38){
                        _this.handleUp();
                    }else if(e.keyCode == 40){
                        _this.handleDown();
                    }
                }
            }
            },
            handleDown:function(){
                if(this.currentValue <= this.min) return;
                console.log(this.stepNum);
                this.currentValue -= this.stepNum;
                // this.currentValue -= 1;
            },
            handleUp:function(){
                if(this.currentValue >= this.max) return;
                this.currentValue += 1;
            },
            updateValue:function(val){
                if(val > this.max) val = this.max;
                if(val < this.min) val = this.min;
                this.currentValue = val;
            },
            handleChange:function(event){
                var val = event.target.value.trim();

                var max = this.max;
                var min = this.min;

                if(isValueNumber(val)){
                    val = Number(val);
                    this.currentValue = val;

                    if(val > max){
                        this.currentValue = max;
                    }else if(val < min){
                        this.currentValue = min;
                    }
                }else{
                    event.target.value = this.currentValue;
                }
            }
        },
        mounted() {
            this.updateValue(this.value);
            //练习部分
            var _this = this;
            // document.onkeydown = function(e){
            //     if(document.getElementsByTagName('input')){
            //         if(e.keyCode == 38){
            //             _this.handleUp();
            //         }else if(e.keyCode == 40){
            //             _this.handleDown();
            //         }
            //     }
            // }
        },
    });
    var app1 = new Vue({
        el:"#app1",
        data:{
            value:5,
            step:5,
        },
    });

    // var app2 = new Vue({
    //     el:"#app2",
    //     data:{
    //         test:''
    //     },
    //     methods:{
    //         print:function(event){
    //             console.log(this,event,event.target.value,this.test);
    //         }
    //     }
    // });
</script>
</html>