低代码——表单生成器Form Generator详解（二）——从JSON配置项到动态渲染表单渲染
在设计低代码表单生成器之前，需要了解组件库相关内容的基础内容
ElementUI中Layout布局与Form表单详解
核心流程
表单生成器从 JSON 配置到动态渲染表单的核心流程如下：
解析 JSON 配置：构建表单的结构和规则组件映射与渲染：将配置转化为可视化表单：表单根组件和表单项（递归，考虑布局列、横）数据绑定与响应式：实现数据的双向流动校验机制：确保数据的合法性表单操作与事件处理：实现交互逻辑
流程总览分析
主要执行流程说明：
-
初始化阶段 ：
- 接收表单配置对象formConf
深拷贝配置，初始化表单数据和验证规则- 处理每个表单组件的默认值和
特殊配置（如文件上传）
-
渲染阶段 ：
- 通过
render函数创建el-form根组件 递归渲染表单项，根据layout类型选择渲染方式- 使用
render组件渲染具体的表单元素
- 通过
-
render组件处理 ：- 创建Vue渲染所需的数据对象
处理插槽内容绑定事件处理器- 构建最终的渲染数据对象
- 渲染具体的表单元素
-
事件处理：统一的表单提交和重置处理各个表单元素的值变更处理- 特殊组件
（如文件上传）的自定义事件处理
文件结构分析
解析配置
/*** 表单解析器核心模块* 负责将JSON配置转换为可渲染的Vue表单组件* 主要功能：* - 表单布局生成* - 数据初始化* - 验证规则构建* - 表单事件处理*/export default {// 组件配置...methods: {/*** 初始化表单数据* @param {Array} componentList - 表单组件配置列表* @param {Object} formData - 表单数据对象*/initFormData(componentList, formData) {// 实现细节...},/*** 构建验证规则* @param {Array} componentList - 表单组件列表* @param {Object} rules - 验证规则容器*/buildRules(componentList, rules) {// 实现细节...}}
}
配置模板
类图说明：
-
FormConfig ：表单全局配置
- 定义表单的基本属性如大小、标签位置等
- 包含一个fields数组存储所有表单组件
-
ComponentConfig ：组件配置
- 包含组件的核心配置( config )和插槽配置( slot )
- 定义组件的模型绑定( vModel )和其他属性
-
ConfigObject ：组件核心配置
- 定义组件的标签、图标、默认值等基本属性
- 包含布局相关的配置如span和layout
- 包含验证规则配置
-
SlotObject ：插槽配置
- 定义组件的插槽内容
- 包含选项数组(用于select、radio等)
- 包含输入框的前后置内容
-
ValidationRule ：验证规则
- 定义必填、正则等验证规则
- 包含验证消息和触发方式
验证规则
- 定义不同表单组件的验证规则触发方式（blur/change）
- 为表单验证系统提供统一的触发机制配置
- 确保表单组件的验证行为一致性
生成代码
js.js
根据表单配置（conf）动态生成 Vue 组件中的 JavaScript 脚本代码，包括 data、rules、methods 等
- 深拷贝配置对象 conf
- 初始化多个代码片段列表：
dataList、ruleList、optionsList、propsList、methodList、uploadVarList - 遍历所有字段，调用 buildAttributes 构造各部分代码
- 汇总成完整脚本并返回
1. 核心执行流程：
- 入口函数 makeUpJs 接收表单配置和类型参数
- 递归处理每个表单字段，构建各种必要的代码片段
- 最终组装生成完整的Vue组件代码
2. 主要函数功能：
- buildAttributes : 递归处理字段属性
- buildData : 处理数据属性和默认值
- buildRules : 构建表单验证规则
- buildOptions : 处理选择器选项配置
- buildProps : 处理组件props
- buildBeforeUpload : 处理文件上传验证
- buildexport : 组装最终组件代码
特点
- 模块化设计，每个函数职责明确
- 支持递归处理复杂表单结构
- 完善的文件上传处理机制
- 灵活的验证规则配置
- 支持动态选项加载
/*** 表单生成器的JavaScript代码生成模块* 负责将JSON配置转换为Vue组件代码*/import { isArray } from 'util'
import { exportDefault, titleCase } from '@/utils/index'
import trigger from './ruleTrigger' // 导入验证规则触发器配置// 文件大小单位换算常量
const units = {KB: '1024',MB: '1024 / 1024',GB: '1024 / 1024 / 1024'
}// 全局配置对象
let confGlobal// 继承属性配置
const inheritAttrs = {file: '',dialog: 'inheritAttrs: false,'
}/*** 生成Vue组件代码的主入口函数* @param {Object} conf - 表单配置对象* @param {String} type - 生成类型(file/dialog)* @returns {String} 生成的Vue组件代码*/
export function makeUpJs(conf, type) {confGlobal = conf = JSON.parse(JSON.stringify(conf))const dataList = []const ruleList = []const optionsList = []const propsList = []const methodList = mixinMethod(type)const uploadVarList = []conf.fields.forEach(el => {buildAttributes(el, dataList, ruleList, optionsList, methodList, propsList, uploadVarList)})const script = buildexport(conf,type,dataList.join('\n'),ruleList.join('\n'),optionsList.join('\n'),uploadVarList.join('\n'),propsList.join('\n'),methodList.join('\n'))confGlobal = nullreturn script
}/*** 构建组件属性* 递归处理表单字段，生成数据、规则、选项等配置* @param {Object} el - 字段配置对象* @param {Array} dataList - 数据属性列表* @param {Array} ruleList - 验证规则列表* @param {Array} optionsList - 选项配置列表* @param {Array} methodList - 方法列表* @param {Array} propsList - 属性列表* @param {Array} uploadVarList - 上传组件变量列表*/
function buildAttributes(el, dataList, ruleList, optionsList, methodList, propsList, uploadVarList) {buildData(el, dataList)buildRules(el, ruleList)if (el.__slot__) {if (el.__slot__.options && el.__slot__.options.length) {buildOptions(el, optionsList)}} else {if (el.options && el.options.length) {buildOptions(el, optionsList)if (el.__config__.dataType === 'dynamic') {const model = `${el.__vModel__}Options`const options = titleCase(model)buildOptionMethod(`get${options}`, model, methodList)}}}if (el.props && el.props.props) {buildProps(el, propsList)}if (el.action && el.__config__.tag === 'el-upload') {uploadVarList.push(`${el.__vModel__}Action: '${el.action}',${el.__vModel__}fileList: [],`)methodList.push(buildBeforeUpload(el))if (!el['auto-upload']) {methodList.push(buildSubmitUpload(el))}}if (el.__config__.children) {el.__config__.children.forEach(el2 => {buildAttributes(el2, dataList, ruleList, optionsList, methodList, propsList, uploadVarList)})}
}/*** 混入默认方法* 根据类型添加默认的表单操作方法* @param {String} type - 组件类型(file/dialog)* @returns {Array} 方法列表*/
function mixinMethod(type) {const list = []; const minxins = {file: confGlobal.formBtns ? {submitForm: `submitForm() {this.$refs['${confGlobal.formRef}'].validate(valid => {if(!valid) return})},`,resetForm: `resetForm() {this.$refs['${confGlobal.formRef}'].resetFields()},`} : null,dialog: {onOpen: 'onOpen() {},',onClose: `onClose() {this.$refs['${confGlobal.formRef}'].resetFields()},`,close: `close() {this.$emit('update:visible', false)},`,handleConfirm: `handleConfirm() {this.$refs['${confGlobal.formRef}'].validate(valid => {if(!valid) returnthis.close()})},`}}const methods = minxins[type]if (methods) {Object.keys(methods).forEach(key => {list.push(methods[key])})}return list
}/*** 构建数据属性* 处理字段的默认值配置* @param {Object} conf - 字段配置* @param {Array} dataList - 数据列表*/
function buildData(conf, dataList) {if (conf.__vModel__ === undefined) returnlet defaultValueif (typeof (conf.__config__.defaultValue) === 'string' && !conf.multiple) {defaultValue = `'${conf.__config__.defaultValue}'`} else {defaultValue = `${JSON.stringify(conf.__config__.defaultValue)}`}dataList.push(`${conf.__vModel__}: ${defaultValue},`)
}/*** 构建验证规则* 处理必填和正则验证规则* @param {Object} conf - 字段配置* @param {Array} ruleList - 规则列表*/
function buildRules(conf, ruleList) {if (conf.__vModel__ === undefined) returnconst rules = []if (trigger[conf.__config__.tag]) {if (conf.__config__.required) {const type = isArray(conf.__config__.defaultValue) ? 'type: \'array\',' : ''let message = isArray(conf.__config__.defaultValue) ? `请至少选择一个${conf.__vModel__}` : conf.placeholderif (message === undefined) message = `${conf.__config__.label}不能为空`rules.push(`{ required: true, ${type} message: '${message}', trigger: '${trigger[conf.__config__.tag]}' }`)}if (conf.__config__.regList && isArray(conf.__config__.regList)) {conf.__config__.regList.forEach(item => {if (item.pattern) {rules.push(`{ pattern: ${eval(item.pattern)}, message: '${item.message}', trigger: '${trigger[conf.__config__.tag]}' }`)}})}ruleList.push(`${conf.__vModel__}: [${rules.join(',')}],`)}
}/*** 构建选项配置* 处理下拉框、级联选择器等的选项数据* @param {Object} conf - 字段配置* @param {Array} optionsList - 选项列表*/
function buildOptions(conf, optionsList) {if (conf.__vModel__ === undefined) returnif (conf.__config__.dataType === 'dynamic') { conf.options = [] }const options = conf.__config__.tag ==='el-cascader'?conf.options:conf.__slot__.options;const str = `${conf.__vModel__}Options: ${JSON.stringify(options)},`optionsList.push(str)
}/*** 构建组件属性* 处理组件的props配置* @param {Object} conf - 字段配置* @param {Array} propsList - 属性列表*/
function buildProps(conf, propsList) {if (conf.__config__.dataType === 'dynamic') {conf.valueKey !== 'value' && (conf.props.props.value = conf.valueKey)conf.labelKey !== 'label' && (conf.props.props.label = conf.labelKey)conf.childrenKey !== 'children' && (conf.props.props.children = conf.childrenKey)}const str = `${conf.__vModel__}Props: ${JSON.stringify(conf.props.props)},`propsList.push(str)
}/*** 构建上传前验证方法* 处理文件大小和类型验证* @param {Object} conf - 上传组件配置* @returns {String} 验证方法代码*/
function buildBeforeUpload(conf) {const unitNum = units[conf.__config__.sizeUnit]; let rightSizeCode = ''; let acceptCode = ''; constreturnList = []if (conf.__config__.fileSize) {rightSizeCode = `let isRightSize = file.size / ${unitNum} < ${conf.__config__.fileSize}if(!isRightSize){this.$message.error('文件大小超过 ${conf.__config__.fileSize}${conf.__config__.sizeUnit}')}`returnList.push('isRightSize')}if (conf.accept) {acceptCode = `let isAccept = new RegExp('${conf.accept}').test(file.type)if(!isAccept){this.$message.error('应该选择${conf.accept}类型的文件')}`returnList.push('isAccept')}const str = `${conf.__vModel__}BeforeUpload(file) {${rightSizeCode}${acceptCode}return ${returnList.join('&&')}},`return returnList.length ? str : ''
}/*** 构建上传提交方法* @param {Object} conf - 上传组件配置* @returns {String} 提交方法代码*/
function buildSubmitUpload(conf) {const str = `submitUpload() {this.$refs['${conf.__vModel__}'].submit()},`return str
}/*** 构建选项加载方法* 用于动态加载选项数据* @param {String} methodName - 方法名* @param {String} model - 数据模型名* @param {Array} methodList - 方法列表*/
function buildOptionMethod(methodName, model, methodList) {const str = `${methodName}() {// TODO 发起请求获取数据this.${model}},`methodList.push(str)
}/*** 构建Vue组件导出代码* 组装最终的组件代码结构* @param {Object} conf - 配置对象* @param {String} type - 组件类型* @param {String} data - 数据定义代码* @param {String} rules - 验证规则代码* @param {String} selectOptions - 选项配置代码* @param {String} uploadVar - 上传变量代码* @param {String} props - 属性定义代码* @param {String} methods - 方法定义代码* @returns {String} 完整的Vue组件代码*/
function buildexport(conf, type, data, rules, selectOptions, uploadVar, props, methods) {const str = `${exportDefault}{${inheritAttrs[type]}components: {},props: [],data () {return {${conf.formModel}: {${data}},${conf.formRules}: {${rules}},${uploadVar}${selectOptions}${props}}},computed: {},watch: {},created () {},mounted () {},methods: {${methods}}
}`return str
}css.js
根据表单字段配置 conf，生成样式（CSS）代码字符串:根据每个字段的 config.tag 类型，从 styles 中匹配对应的样式字符串并加入 CSS 列表，最后拼接成一个完整的样式字符串返回。
const styles = {'el-rate': '.el-rate{display: inline-block; vertical-align: text-top;}','el-upload': '.el-upload__tip{line-height: 1.2;}'
}function addCss(cssList, el) {const css = styles[el.__config__.tag]css && cssList.indexOf(css) === -1 && cssList.push(css)if (el.__config__.children) {el.__config__.children.forEach(el2 => addCss(cssList, el2))}
}export function makeUpCss(conf) {const cssList = []conf.fields.forEach(el => addCss(cssList, el))return cssList.join('\n')
}
html.js
根据配置对象 (conf) 自动构建可复用的
Vue 表单模板
此模块的核心作用是：
- 根据配置生成动态的 Vue 表单代码，包括
样式、控件、布局。 - 通过
组件映射和插槽机制提升扩展性和可维护性。 - 支持 Element UI 的
各种表单控件与弹窗包装，适用于低代码平台表单生成器。
主函数
export function makeUpHtml(conf, type) {const htmlList = []confGlobal = confsomeSpanIsNot24 = conf.fields.some(item => item.span !== 24)conf.fields.forEach(el => {htmlList.push(layouts[el.__config__.layout](el))})//表单子元素const htmlStr = htmlList.join('\n')//表单let temp = buildFormTemplate(conf, htmlStr, type)//是否弹出框形式显示if (type === 'dialog') {temp = dialogWrapper(temp)}confGlobal = nullreturn temp
}
构建表单子元素
布局
layouts : 包含两种布局处理器：
- colFormItem : 处理单列表单项
- rowFormItem : 处理行布局，可包含多个子元素
const layouts = {colFormItem(element) {let labelWidth = ''if (element.__config__.labelWidth && element.__config__.labelWidth !== confGlobal.labelWidth) {labelWidth = `label-width="${element.__config__.labelWidth}px"`}const required = !trigger[element.__config__.tag] && element.__config__.required ? 'required' : ''const tagDom = tags[element.__config__.tag] ? tags[element.__config__.tag](element) : nulllet str = `<el-form-item ${labelWidth} label="${element.__config__.label}" prop="${element.__vModel__}" ${required}>${tagDom}</el-form-item>`str = colWrapper(element, str)return str},rowFormItem(element) {const type = element.type === 'default' ? '' : `type="${element.type}"`const justify = element.type === 'default' ? '' : `justify="${element.justify}"`const align = element.type === 'default' ? '' : `align="${element.align}"`const gutter = element.gutter ? `gutter="${element.gutter}"` : ''const children = element.__config__.children.map(el => layouts[el.__config__.layout](el))let str = `<el-row ${type} ${justify} ${align} ${gutter}>${children.join('\n')}</el-row>`str = colWrapper(element, str)return str}
}
子元素映射
const tags = {'el-button': el => {const {tag, disabled} = attrBuilder(el)const type = el.type ? `type="${el.type}"` : ''const icon = el.icon ? `icon="${el.icon}"` : ''const size = el.size ? `size="${el.size}"` : ''let child = buildElButtonChild(el)if (child) child = `\n${child}\n` // 换行return `<${el.__config__.tag} ${type} ${icon} ${size} ${disabled}>${child}</${el.__config__.tag}>`},'el-input': el => {const {disabled, vModel, clearable, placeholder, width} = attrBuilder(el)const maxlength = el.maxlength ? `:maxlength="${el.maxlength}"` : ''const showWordLimit = el['show-word-limit'] ? 'show-word-limit' : ''const readonly = el.readonly ? 'readonly' : ''const prefixIcon = el['prefix-icon'] ? `prefix-icon='${el['prefix-icon']}'` : ''const suffixIcon = el['suffix-icon'] ? `suffix-icon='${el['suffix-icon']}'` : ''const showPassword = el['show-password'] ? 'show-password' : ''const type = el.type ? `type="${el.type}"` : ''const autosize = el.autosize && el.autosize.minRows? `:autosize="{minRows: ${el.autosize.minRows}, maxRows: ${el.autosize.maxRows}}"`: ''let child = buildElInputChild(el)if (child) child = `\n${child}\n` // 换行return `<${el.__config__.tag} ${vModel} ${type} ${placeholder} ${maxlength} ${showWordLimit} ${readonly} ${disabled} ${clearable} ${prefixIcon} ${suffixIcon} ${showPassword} ${autosize} ${width}>${child}</${el.__config__.tag}>`},'el-input-number': el => {const { disabled, vModel, placeholder } = attrBuilder(el)const controlsPosition = el['controls-position'] ? `controls-position=${el['controls-position']}` : ''const min = el.min ? `:min='${el.min}'` : ''const max = el.max ? `:max='${el.max}'` : ''const step = el.step ? `:step='${el.step}'` : ''const stepStrictly = el['step-strictly'] ? 'step-strictly' : ''const precision = el.precision ? `:precision='${el.precision}'` : ''return `<${el.__config__.tag} ${vModel} ${placeholder} ${step} ${stepStrictly} ${precision} ${controlsPosition} ${min} ${max} ${disabled}></${el.__config__.tag}>`},'el-select': el => {const {disabled, vModel, clearable, placeholder, width} = attrBuilder(el)const filterable = el.filterable ? 'filterable' : ''const multiple = el.multiple ? 'multiple' : ''let child = buildElSelectChild(el)if (child) child = `\n${child}\n` // 换行return `<${el.__config__.tag} ${vModel} ${placeholder} ${disabled} ${multiple} ${filterable} ${clearable} ${width}>${child}</${el.__config__.tag}>`},'el-radio-group': el => {const { disabled, vModel } = attrBuilder(el)const size = `size="${el.size}"`let child = buildElRadioGroupChild(el)if (child) child = `\n${child}\n` // 换行return `<${el.__config__.tag} ${vModel} ${size} ${disabled}>${child}</${el.__config__.tag}>`},'el-checkbox-group': el => {const { disabled, vModel } = attrBuilder(el)const size = `size="${el.size}"`const min = el.min ? `:min="${el.min}"` : ''const max = el.max ? `:max="${el.max}"` : ''let child = buildElCheckboxGroupChild(el)if (child) child = `\n${child}\n` // 换行return `<${el.__config__.tag} ${vModel} ${min} ${max} ${size} ${disabled}>${child}</${el.__config__.tag}>`},'el-switch': el => {const { disabled, vModel } = attrBuilder(el)const activeText = el['active-text'] ? `active-text="${el['active-text']}"` : ''const inactiveText = el['inactive-text'] ? `inactive-text="${el['inactive-text']}"` : ''const activeColor = el['active-color'] ? `active-color="${el['active-color']}"` : ''const inactiveColor = el['inactive-color'] ? `inactive-color="${el['inactive-color']}"` : ''const activeValue = el['active-value'] !== true ? `:active-value='${JSON.stringify(el['active-value'])}'` : ''const inactiveValue = el['inactive-value'] !== false ? `:inactive-value='${JSON.stringify(el['inactive-value'])}'` : ''return `<${el.__config__.tag} ${vModel} ${activeText} ${inactiveText} ${activeColor} ${inactiveColor} ${activeValue} ${inactiveValue} ${disabled}></${el.__config__.tag}>`},'el-cascader': el => {const {disabled, vModel, clearable, placeholder, width} = attrBuilder(el)const options = el.options ? `:options="${el.__vModel__}Options"` : ''const props = el.props ? `:props="${el.__vModel__}Props"` : ''const showAllLevels = el['show-all-levels'] ? '' : ':show-all-levels="false"'const filterable = el.filterable ? 'filterable' : ''const separator = el.separator === '/' ? '' : `separator="${el.separator}"`return `<${el.__config__.tag} ${vModel} ${options} ${props} ${width} ${showAllLevels} ${placeholder} ${separator} ${filterable} ${clearable} ${disabled}></${el.__config__.tag}>`},'el-slider': el => {const { disabled, vModel } = attrBuilder(el)const min = el.min ? `:min='${el.min}'` : ''const max = el.max ? `:max='${el.max}'` : ''const step = el.step ? `:step='${el.step}'` : ''const range = el.range ? 'range' : ''const showStops = el['show-stops'] ? `:show-stops="${el['show-stops']}"` : ''return `<${el.__config__.tag} ${min} ${max} ${step} ${vModel} ${range} ${showStops} ${disabled}></${el.__config__.tag}>`},'el-time-picker': el => {const {disabled, vModel, clearable, placeholder, width} = attrBuilder(el)const startPlaceholder = el['start-placeholder'] ? `start-placeholder="${el['start-placeholder']}"` : ''const endPlaceholder = el['end-placeholder'] ? `end-placeholder="${el['end-placeholder']}"` : ''const rangeSeparator = el['range-separator'] ? `range-separator="${el['range-separator']}"` : ''const isRange = el['is-range'] ? 'is-range' : ''const format = el.format ? `format="${el.format}"` : ''const valueFormat = el['value-format'] ? `value-format="${el['value-format']}"` : ''const pickerOptions = el['picker-options'] ? `:picker-options='${JSON.stringify(el['picker-options'])}'` : ''return `<${el.__config__.tag} ${vModel} ${isRange} ${format} ${valueFormat} ${pickerOptions} ${width} ${placeholder} ${startPlaceholder} ${endPlaceholder} ${rangeSeparator} ${clearable} ${disabled}></${el.__config__.tag}>`},'el-date-picker': el => {const {disabled, vModel, clearable, placeholder, width} = attrBuilder(el)const startPlaceholder = el['start-placeholder'] ? `start-placeholder="${el['start-placeholder']}"` : ''const endPlaceholder = el['end-placeholder'] ? `end-placeholder="${el['end-placeholder']}"` : ''const rangeSeparator = el['range-separator'] ? `range-separator="${el['range-separator']}"` : ''const format = el.format ? `format="${el.format}"` : ''const valueFormat = el['value-format'] ? `value-format="${el['value-format']}"` : ''const type = el.type === 'date' ? '' : `type="${el.type}"`const readonly = el.readonly ? 'readonly' : ''return `<${el.__config__.tag} ${type} ${vModel} ${format} ${valueFormat} ${width} ${placeholder} ${startPlaceholder} ${endPlaceholder} ${rangeSeparator} ${clearable} ${readonly} ${disabled}></${el.__config__.tag}>`},'el-rate': el => {const { disabled, vModel } = attrBuilder(el)const max = el.max ? `:max='${el.max}'` : ''const allowHalf = el['allow-half'] ? 'allow-half' : ''const showText = el['show-text'] ? 'show-text' : ''const showScore = el['show-score'] ? 'show-score' : ''return `<${el.__config__.tag} ${vModel} ${max} ${allowHalf} ${showText} ${showScore} ${disabled}></${el.__config__.tag}>`},'el-color-picker': el => {const { disabled, vModel } = attrBuilder(el)const size = `size="${el.size}"`const showAlpha = el['show-alpha'] ? 'show-alpha' : ''const colorFormat = el['color-format'] ? `color-format="${el['color-format']}"` : ''return `<${el.__config__.tag} ${vModel} ${size} ${showAlpha} ${colorFormat} ${disabled}></${el.__config__.tag}>`},'el-upload': el => {const disabled = el.disabled ? ':disabled=\'true\'' : ''const action = el.action ? `:action="${el.__vModel__}Action"` : ''const multiple = el.multiple ? 'multiple' : ''const listType = el['list-type'] !== 'text' ? `list-type="${el['list-type']}"` : ''const accept = el.accept ? `accept="${el.accept}"` : ''const name = el.name !== 'file' ? `name="${el.name}"` : ''const autoUpload = el['auto-upload'] === false ? ':auto-upload="false"' : ''const beforeUpload = `:before-upload="${el.__vModel__}BeforeUpload"`const fileList = `:file-list="${el.__vModel__}fileList"`const ref = `ref="${el.__vModel__}"`let child = buildElUploadChild(el)if (child) child = `\n${child}\n` // 换行return `<${el.__config__.tag} ${ref} ${fileList} ${action} ${autoUpload} ${multiple} ${beforeUpload} ${listType} ${accept} ${name} ${disabled}>${child}</${el.__config__.tag}>`},tinymce: el => {const { tag, vModel, placeholder } = attrBuilder(el)const height = el.height ? `:height="${el.height}"` : ''const branding = el.branding ? `:branding="${el.branding}"` : ''return `<${tag} ${vModel} ${placeholder} ${height} ${branding}></${tag}>`}
}function attrBuilder(el) {return {vModel: `v-model="${confGlobal.formModel}.${el.__vModel__}"`,clearable: el.clearable ? 'clearable' : '',placeholder: el.placeholder ? `placeholder="${el.placeholder}"` : '',width: el.style && el.style.width ? ':style="{width: \'100%\'}"' : '',disabled: el.disabled ? ':disabled=\'true\'' : ''}
}子元素构建
// el-button 子级
function buildElButtonChild(conf) {const children = []if (conf.__config__.defaultValue) {children.push(conf.__config__.defaultValue)}return children.join('\n')
}// el-input innerHTML
function buildElInputChild(conf) {const children = []if (conf.__slot__ && conf.__slot__.prepend) {children.push(`<template slot="prepend">${conf.__slot__.prepend}</template>`)}if (conf.__slot__ && conf.__slot__.append) {children.push(`<template slot="append">${conf.__slot__.append}</template>`)}return children.join('\n')
}function buildElSelectChild(conf) {const children = []if (conf.__slot__.options && conf.__slot__.options.length) {children.push(`<el-option v-for="(item, index) in ${conf.__vModel__}Options" :key="index" :label="item.label" :value="item.value" :disabled="item.disabled"></el-option>`)}return children.join('\n')
}function buildElRadioGroupChild(conf) {const children = []if (conf.__slot__.options && conf.__slot__.options.length) {const tag = conf.__config__.optionType === 'button' ? 'el-radio-button' : 'el-radio'const border = conf.__config__.border ? 'border' : ''children.push(`<${tag} v-for="(item, index) in ${conf.__vModel__}Options" :key="index" :label="item.value" :disabled="item.disabled" ${border}>{{item.label}}</${tag}>`)}return children.join('\n')
}function buildElCheckboxGroupChild(conf) {const children = []if (conf.__slot__.options && conf.__slot__.options.length) {const tag = conf.__config__.optionType === 'button' ? 'el-checkbox-button' : 'el-checkbox'const border = conf.__config__.border ? 'border' : ''children.push(`<${tag} v-for="(item, index) in ${conf.__vModel__}Options" :key="index" :label="item.value" :disabled="item.disabled" ${border}>{{item.label}}</${tag}>`)}return children.join('\n')
}function buildElUploadChild(conf) {const list = []if (conf['list-type'] === 'picture-card') list.push('<i class="el-icon-plus"></i>')else list.push(`<el-button size="small" type="primary" icon="el-icon-upload">${conf.__config__.buttonText}</el-button>`)if (conf.__config__.showTip) list.push(`<div slot="tip" class="el-upload__tip">只能上传不超过 ${conf.__config__.fileSize}${conf.__config__.sizeUnit} 的${conf.accept}文件</div>`)return list.join('\n')
}
表单模板
export function dialogWrapper(str) {return `<el-dialog v-bind="$attrs" v-on="$listeners" @open="onOpen" @close="onClose" title="Dialog Title">${str}<div slot="footer"><el-button @click="close">取消</el-button><el-button type="primary" @click="handleConfirm">确定</el-button></div></el-dialog>`
}export function vueTemplate(str) {return `<template><div>${str}</div></template>`
}export function vueScript(str) {return `<script>${str}</script>`
}export function cssStyle(cssStr) {return `<style>${cssStr}</style>`
}function buildFormTemplate(conf, child, type) {let labelPosition = ''if (conf.labelPosition !== 'right') {labelPosition = `label-position="${conf.labelPosition}"`}const disabled = conf.disabled ? `:disabled="${conf.disabled}"` : ''let str = `<el-form ref="${conf.formRef}" :model="${conf.formModel}" :rules="${conf.formRules}" size="${conf.size}" ${disabled} label-width="${conf.labelWidth}px" ${labelPosition}>${child}${buildFromBtns(conf, type)}</el-form>`if (someSpanIsNot24) {str = `<el-row :gutter="${conf.gutter}">${str}</el-row>`}return str
}function buildFromBtns(conf, type) {let str = ''if (conf.formBtns && type === 'file') {str = `<el-form-item size="large"><el-button type="primary" @click="submitForm">提交</el-button><el-button @click="resetForm">重置</el-button></el-form-item>`if (someSpanIsNot24) {str = `<el-col :span="24">${str}</el-col>`}}return str
}
渲染组件
render.js是表单生成器的渲染核心模块，负责将JSON配置转换为实际的Vue组件。以下是详细分析：
- 文件结构和主要功能：
- 实现了一个基于Vue render函数的
表单渲染器 - 支持
动态插槽加载和事件处理 - 提供完整的数据对象构建流程
- 核心执行流程：
- 初始化时
动态加载插槽组件 - 通过render函数
将配置转换为DOM - 处理
v-model、事件绑定和属性配置
- 主要函数功能：
vModel: 处理双向数据绑定mountSlotFiles:挂载插槽内容emitEvents: 处理事件发射- buildDataObject : 构建
渲染数据对象 - makeDataObject : 创建
基础数据结构
- 特点和优势：
- 灵活的
插槽系统：支持动态加载和自定义插槽内容 - 完善的
事件处理：自动转换事件处理器 - 强大的数据处理：支持
多种数据类型和属性合并 - 清晰的代码结构：职责分明，易于维护
- 与其他模块的关系：
- 配合 js.js 处理组件逻辑
- 与 html.js 协同生成完整组件
- 使用 deepClone 确保配置对象的独立性
- render.js 与 js.js 配合处理Vue组件逻辑生成
- 与 html.js 协同完成组件模板和数据绑定
- 通过 deepClone 工具函数确保配置对象的深拷贝独立性
- 使用不同样式区分核心模块( module )和工具函数( tool )
-
- render.js 与 js.js 配合处理Vue组件逻辑生成
- 与 html.js 协同完成组件模板和数据绑定
- 通过 deepClone 工具函数确保配置对象的深拷贝独立性
- 使用不同样式区分核心模块( module )和工具函数( tool )
/*** 表单渲染器模块* 负责将字符串形式配置转换为Vue渲染函数* 支持自定义插槽和事件处理*/import { deepClone } from '@/utils/index'// 组件插槽配置对象
const componentChild = {}/*** 动态导入并注册插槽组件* 将./slots目录下的所有.js文件挂载到componentChild对象* @param {Object} componentChild - 组件插槽配置对象* @param {Function} require.context - Webpack的require.context函数*/
const slotsFiles = require.context('./slots', false, /\.js$/)
const keys = slotsFiles.keys() || []
keys.forEach(key => {const tag = key.replace(/^\.\/(.*)\.\w+$/, '$1')componentChild[tag] = slotsFiles(key).default
})/*** 处理组件的v-model指令* @param {Object} dataObject - 组件数据对象* @param {*} defaultValue - 默认值*/
function vModel(dataObject, defaultValue) {dataObject.props.value = defaultValuedataObject.on.input = val => {this.$emit('input', val)}
}/*** 挂载插槽内容* @param {Function} h - Vue的createElement函数* @param {Object} confClone - 组件配置对象的克隆* @param {Array} children - 子节点数组*/
function mountSlotFiles(h, confClone, children) {const childObjs = componentChild[confClone.__config__.tag]if (childObjs) {Object.keys(childObjs).forEach(key => {const childFunc = childObjs[key]if (confClone.__slot__ && confClone.__slot__[key]) {children.push(childFunc(h, confClone, key))}})}
}/*** 处理事件发射* 将字符串类型的事件处理器转换为实际的函数* @param {Object} confClone - 组件配置对象的克隆*/
function emitEvents(confClone) {['on', 'nativeOn'].forEach(attr => {const eventKeyList = Object.keys(confClone[attr] || {})eventKeyList.forEach(key => {const val = confClone[attr][key]if (typeof val === 'string') {confClone[attr][key] = event => this.$emit(val, event)}})})
}/*** 构建组件的数据对象* 处理props、attrs等配置* @param {Object} confClone - 组件配置对象的克隆* @param {Object} dataObject - 渲染数据对象*/
function buildDataObject(confClone, dataObject) {Object.keys(confClone).forEach(key => {const val = confClone[key]if (key === '__vModel__') {vModel.call(this, dataObject, confClone.__config__.defaultValue)} else if (dataObject[key] !== undefined) {if (dataObject[key] === null|| dataObject[key] instanceof RegExp|| ['boolean', 'string', 'number', 'function'].includes(typeof dataObject[key])) {dataObject[key] = val} else if (Array.isArray(dataObject[key])) {dataObject[key] = [...dataObject[key], ...val]} else {dataObject[key] = { ...dataObject[key], ...val }}} else {dataObject.attrs[key] = val}})// 清理属性clearAttrs(dataObject)
}/*** 清理内部使用的属性* @param {Object} dataObject - 渲染数据对象*/
function clearAttrs(dataObject) {delete dataObject.attrs.__config__delete dataObject.attrs.__slot__delete dataObject.attrs.__methods__
}/*** 创建渲染函数数据对象的基础结构* 包含class、attrs、props等Vue渲染函数所需的所有属性* @returns {Object} 渲染数据对象*/
function makeDataObject() {// 深入数据对象：// https://cn.vuejs.org/v2/guide/render-function.html#%E6%B7%B1%E5%85%A5%E6%95%B0%E6%8D%AE%E5%AF%B9%E8%B1%A1return {class: {},attrs: {},props: {},domProps: {},nativeOn: {},on: {},style: {},directives: [],scopedSlots: {},slot: null,key: null,ref: null,refInFor: true}
}/*** 表单渲染器组件* 使用Vue的render函数将JSON配置转换为实际的DOM*/
export default {props: {conf: {type: Object,required: true}},render(h) {const dataObject = makeDataObject()const confClone = deepClone(this.conf)const children = this.$slots.default || []// 如果slots文件夹存在与当前tag同名的文件，则执行文件中的代码mountSlotFiles.call(this, h, confClone, children)// 将字符串类型的事件，发送为消息emitEvents.call(this, confClone)// 将json表单配置转化为vue render可以识别的 “数据对象（dataObject）”buildDataObject.call(this, confClone, dataObject)return h(this.conf.__config__.tag, dataObject, children)}
}