摘要：原文地址的博客点击在线尝试一下最终效果如下构造器构造一个对象，包含基本的，，初始化编译器用于解析绑定到输入框和下拉框的和元素的点击事件。

原文地址：Bougie的博客

点击在线尝试一下

最终效果如下：

构造一个TinyVue对象，包含基本的el，data，methods

class TinyVue{
    constructor({el, data, methods}){
        this.$data = data
        this.$el = document.querySelector(el)
        this.$methods = methods
        // 初始化
        this._compile()
        this._updater()
        this._watcher()
    }
}

用于解析绑定到输入框和下拉框的v-model和元素的点击事件@click。
先创建一个函数用来载入事件：

// el为元素tagName，attr为元素属性（v-model，@click）
_initEvents(el, attr, callBack) {
    this.$el.querySelectorAll(el).forEach(i => {
        if(i.hasAttribute(attr)) {
            let key = i.getAttribute(attr)
            callBack(i, key)
        }
    })
}

this._initEvents("input, textarea", "v-model", (i, key) => {
    i.addEventListener("input", () => {
        Object.assign(this.$data, {[key]: i.value})
    })
})

this._initEvents("select", "v-model", (i, key) => {
    i.addEventListener("change", () => Object.assign(this.$data, {[key]: i.options[i.options.selectedIndex].value}))
})

点击事件对应的是methods中的事件

this._initEvents("*", "@click", (i, key) => {
    i.addEventListener("click", () => this.$methods[key].bind(this.$data)())
})

同理先创建公共函数来处理不同元素中的视图，包括input、textarea的value，select的选择值，div的innerHTML

_initView(el, attr, callBack) {
    this.$el.querySelectorAll(el, attr, callBack).forEach(i => {
        if(i.hasAttribute(attr)) {
            let key = i.getAttribute(attr),
                data = this.$data[key]
            callBack(i, key, data)
        }
    })
}

this._initView("input, textarea", "v-model", (i, key, data) => {
    i.value = data
})

this._initView("select", "v-model", (i, key, data) => {
    i.querySelectorAll("option").forEach(v => {
        if(v.value == data) v.setAttribute("selected", true)
        else v.removeAttribute("selected")
    })
})

这里实现方法有点low，仅想到正则替换{{text}}

let regExpInner = /{{ *([w_-]+) *}}/g
this.$el.querySelectorAll("*").forEach(i => {
    let replaceList = i.innerHTML.match(regExpInner) || (i.hasAttribute("vueID") && i.getAttribute("vueID").match(regExpInner))
    if(replaceList) {
        if(!i.hasAttribute("vueID")) {
            i.setAttribute("vueID", i.innerHTML)
        }
        i.innerHTML = i.getAttribute("vueID")
        replaceList.forEach(v => {
            let key = v.slice(2, v.length - 2)
            i.innerHTML = i.innerHTML.replace(v, this.$data[key])
        })
    }
})

数据变化之后更新视图

_watcher(data = this.$data) {
    let that = this
    Object.keys(data).forEach(i => {
        let value = data[i]
        Object.defineProperty(data, i, {
            enumerable: true,
            configurable: true,
            get: function () {
                return value;
            },
            set: function (newVal) {
                if (value !== newVal) {
                    value = newVal;
                    that._updater()
                }
            }
        })
    })
}

    

    

    

    加一
    
您输入的是：{{text1}}+{{text2}}+{{text3}}
    
        Volvo
        Saab
    
    
        Volvo
        Saab
    
    
您选择了：{{select}}

class TinyVue{
    constructor({el, data, methods}){
        this.$data = data
        this.$el = document.querySelector(el)
        this.$methods = methods
        this._compile()
        this._updater()
        this._watcher()
    }
    _watcher(data = this.$data) {
        let that = this
        Object.keys(data).forEach(i => {
            let value = data[i]
            Object.defineProperty(data, i, {
                enumerable: true,
                configurable: true,
                get: function () {
                    return value;
                },
                set: function (newVal) {
                    if (value !== newVal) {
                        value = newVal;
                        that._updater()
                    }
                }
            })
        })
    }
    _initEvents(el, attr, callBack) {
        this.$el.querySelectorAll(el).forEach(i => {
            if(i.hasAttribute(attr)) {
                let key = i.getAttribute(attr)
                callBack(i, key)
            }
        })
    }
    _initView(el, attr, callBack) {
        this.$el.querySelectorAll(el, attr, callBack).forEach(i => {
            if(i.hasAttribute(attr)) {
                let key = i.getAttribute(attr),
                    data = this.$data[key]
                callBack(i, key, data)
            }
        })
    }
    _updater() {
        this._initView("input, textarea", "v-model", (i, key, data) => {
            i.value = data
        })
        this._initView("select", "v-model", (i, key, data) => {
            i.querySelectorAll("option").forEach(v => {
                if(v.value == data) v.setAttribute("selected", true)
                else v.removeAttribute("selected")
            })
        })
        let regExpInner = /{{ *([w_-]+) *}}/g
        this.$el.querySelectorAll("*").forEach(i => {
            let replaceList = i.innerHTML.match(regExpInner) || (i.hasAttribute("vueID") && i.getAttribute("vueID").match(regExpInner))
            if(replaceList) {
                if(!i.hasAttribute("vueID")) {
                    i.setAttribute("vueID", i.innerHTML)
                }
                i.innerHTML = i.getAttribute("vueID")
                replaceList.forEach(v => {
                    let key = v.slice(2, v.length - 2)
                    i.innerHTML = i.innerHTML.replace(v, this.$data[key])
                })
            }
        })
    }
    _compile() {
        this._initEvents("*", "@click", (i, key) => {
            i.addEventListener("click", () => this.$methods[key].bind(this.$data)())
        })
        this._initEvents("input, textarea", "v-model", (i, key) => {
            i.addEventListener("input", () => {
                Object.assign(this.$data, {[key]: i.value})
            })
        })
        this._initEvents("select", "v-model", (i, key) => {
            i.addEventListener("change", () => Object.assign(this.$data, {[key]: i.options[i.options.selectedIndex].value}))
        })
    }
}