1.插槽

插槽感觉知道有这个东西，但是挺少用过的，每次看到基本都会再去看一遍用法和概念。但是在项目里，自己还是没有用到过。总结下一些可能用到的场景，下次直接这样写了。

1.1 自定义列表渲染

<script setup>
import HelloWorld from './components/HelloWorld.vue'
import { reactive } from 'vue';
const myItems = reactive([{name: 'A',age: 18},{name: 'B',age: 19},{name: 'C',age: 20}
]
)
</script>
<template><HelloWorld :items="myItems"><template v-slot:default="slotProps"><span>{{ slotProps.item.name }}</span><button @click="doSomething(slotProps.item)">操作</button></template></HelloWorld>
</template><script setup>
import { defineProps } from 'vue';defineProps({items: {type: Array,default: () => []}
})
</script>
<template><ul><li v-for="item in items" :key="item.id"><slot :item="item"></slot></li></ul>
</template>

效果：

拓展性很强。

1.2 数据表格组件

<script setup>
import HelloWorld from './components/HelloWorld.vue'
import { reactive } from 'vue';
const tableData = reactive([{name: 'A',age: 18},{name: 'B',age: 19},{name: 'C',age: 20}]
)const columns = reactive([{label: '姓名',key: 'name'},{label: '年龄',key: 'age'},{label: '性别',key: 'sex'},{ key: 'actions', label: '操作' }]
)
</script>
<template><HelloWorld :columns="columns" :data="tableData"><template v-slot:actions="{ row }"><button @click="edit(row)">编辑</button><button @click="del(row)">删除</button></template></HelloWorld>
</template><template><table><thead><tr><th v-for="column in columns" :key="column.key">{{ column.label }}</th></tr></thead><tbody><tr v-for="row in data" :key="row.id"><td v-for="column in columns" :key="column.key"><slot :name="column.key" :row="row">{{ row[column.key] }}</slot></td></tr></tbody></table>
</template><script setup>
import { defineProps } from 'vue';
defineProps({columns: Array,data: Array,
});
</script>

效果：

1.3 树形组件

<template><div class="tree-node"><slot :node="node" :toggle="toggle" :expandTree="expandTree" name="trangle"><span v-if="node.children.length > 0" @click="toggle">{{ expanded ? '▼' : '▶' }}</span></slot><slot :node="node" :toggle="toggle" :expandTree="expandTree"><div>{{ node.label }}</div></slot><div v-if="expanded" class="tree-node-children"><HelloWorld v-for="child in node.children" :key="child.id" :node="child"><template v-slot="childSlotProps"><slot v-bind="childSlotProps"></slot></template></HelloWorld></div></div>
</template>
<script setup>
import HelloWorld from './HelloWorld.vue'
import { defineProps, ref } from 'vue';
const props = defineProps({node: {type: Object,required: true}
})
const expanded = ref(false)
const toggle = () => {console.log(999)expanded.value = !expanded.value
}
const expandTree = () => {expanded.value = true
}
</script>
<style>
.tree-node {position: relative;cursor: pointer;
}.tree-node-children {position: relative;padding-left: 20px;/* 这个值决定了每一层的缩进量 */
}.tree-node>span {margin-left: 0;
}
</style><script setup>
import HelloWorld from './components/HelloWorld.vue'
import { reactive } from 'vue';const rootNode = reactive({id: 1,label: '根节点',children: [{id: 2, label: '子节点1', children: [{ id: 3, label: '子节点1-1', children: [] }]},{ id: 4, label: '子节点2', children: [] }]
})const addChild = (node, expandTree) => {const newId = Date.now()expandTree()node.children.push({id: newId,label: `新子节点${newId}`,children: []})
}
</script>
<template><HelloWorld :node="rootNode"><template v-slot="{ node, toggle, expandTree }"><span @click="toggle">{{ node.label }}</span><button @click="addChild(node, expandTree)">添加子节点</button></template></HelloWorld>
</template>

效果：

1.4 表单验证组件

<script setup>
import { ref, watch, defineProps, defineEmits } from 'vue'const props = defineProps({rules: {type: Array,default: () => []},modelValue: {type: String,default: ''}
})const emit = defineEmits(['update:modelValue'])const value = ref(props.modelValue)
const error = ref('')const validate = () => {for (const rule of props.rules) {if (!rule.validate(value.value)) {error.value = rule.messagereturn false}}error.value = ''return true
}watch(() => props.modelValue, (newValue) => {value.value = newValue
})watch(value, (newValue) => {emit('update:modelValue', newValue)
})
</script><template><div class="a"><slot :value="value" :error="error" :validate="validate"></slot><span v-if="error">{{ error }}</span></div>
</template>
<style lang="scss" scoped>
.a{position: relative;span{color: red;position: absolute;left: 0;bottom: -24px;font-size: 14px;}
}</style>//使用
<script setup>
import FormField from './components/HelloWorld.vue'
import { ref } from 'vue';const email = ref('')const emailRules = [{validate: (value) => /.+@.+\..+/.test(value),message: '请输入有效的电子邮件地址'}
]
</script>
<template><FormField :rules="emailRules" v-model="email"><template v-slot="{ value, error, validate }">邮箱<input :value="value" @input="$event => { email = $event.target.value; validate(); }":class="{ 'is-invalid': error }" /></template></FormField>
</template><style >
input{outline: none;
}
.is-invalid:focus {border-color: red;
}
</style>

效果：

1.5 无限滚动组件

<script setup>
import { ref, onMounted, defineProps } from 'vue'const props = defineProps({fetchItems: {type: Function,required: true}
})const visibleItems = ref([])
const loading = ref(false)const handleScroll = async (event) => {const { scrollTop, scrollHeight, clientHeight } = event.targetif (scrollTop + clientHeight >= scrollHeight - 20 && !loading.value) {loading.value = trueconst newItems = await props.fetchItems()visibleItems.value = [...visibleItems.value, ...newItems]loading.value = false}
}onMounted(async () => {visibleItems.value = await props.fetchItems()
})
</script><template><div @scroll="handleScroll" style="height: 200px; overflow-y: auto;"><slot :items="visibleItems"></slot><div v-if="loading">加载中...</div></div>
</template>//使用
<script setup>
import InfiniteScroll from './components/HelloWorld.vue'
import { ref } from 'vue';let page = 0
const fetchMoreItems = async () => {// 模拟API调用await new Promise(resolve => setTimeout(resolve, 1000))page++return Array.from({ length: 10 }, (_, i) => ({id: page * 10 + i,content: `Item ${page * 10 + i}`}))
}
</script>
<template><InfiniteScroll :fetch-items="fetchMoreItems"><template #default="{ items }"><div v-for="item in items" :key="item.id">{{ item.content }}</div></template></InfiniteScroll>
</template>