我正在尝试在类别之间建立一个菜单。如果一个类别有一个子类别,它会返回一个值,表示 has_subCategory 为 bool 值 0/1。
<template>
<select><slot></slot></select>
</template>
<script>
export default {
props: ['value',
'hasSubCat'],
watch: {
value: function(value, hasSubCat) {
this.relaod(value);
this.fetchSubCategories(value, hasSubCat);
}
},
methods: {
relaod: function(value) {
var select = $(this.$el);
select.val(value || this.value);
select.material_select('destroy');
select.material_select();
},
fetchSubCategories: function(value, hasSubCat) {
var mdl = this;
var catID = value || this.value;
var has_subCat = hasSubCat || this.hasSubCat;
console.log("has_subCat:" + has_subCat);
mdl.$emit("reset-subcats");
if (catID) {
if (has_subCat == 0) {
if ($('.subdropdown').is(":visible") == true) {
$('.subdropdown').fadeOut();
}
} else {
axios.get(URL.API + '/subcategories/' + catID)
.then(function(response) {
response = response.data.subcatData;
response.unshift({
subcat_id: '0',
subcategory_name: 'All Subcategories'
});
mdl.$emit("update-subcats", response);
$('.subdropdown').fadeIn();
})
.catch(function(error) {
if (error.response.data) {
swal({
title: "Something went wrong",
text: "Please try again",
type: "error",
html: false
});
}
});
}
} else {
if ($('.subdropdown').is(":visible") == true) {
$('.subdropdown').fadeOut();
}
}
}
},
mounted: function() {
var vm = this;
var select = $(this.$el);
select
.val(this.value)
.on('change', function() {
vm.$emit('input', this.value);
});
select.material_select();
},
updated: function() {
this.relaod();
},
destroyed: function() {
$(this.$el).material_select('destroy');
}
}
</script>
<material-selectcat v-model="catId" name="category" @reset-subcats="resetSubCats" @update-subcats="updateSubCats" id="selcat">
<option v-for="cat in cats" :value="cat.cat_id" :hasSubCat="cat.has_subCat" v-text="cat.category_name"></option>
</material-selectcat>
数据如下所示:
cat_id:"0"
category_name:"All Subcategories"
has_subCat:0
我不明白的是,console.log("has_subCat:"+ hasSubCat); 每次更改选择时都会打印出不同的值。它应该只显示 0 或 1
最佳答案
vue.js 中的 Watcher 应该用于监视一个值,但您可以使用 help of computed
来满足您的要求.
export default {
props: ['value',
'hasSubCat'],
watch: {
/* without this, watcher won't be evaluated */
watcher: function() {}
},
computed: {
watcher: function() {
this.reload(this.value);
this.fetchSubCategories(this.value, this.hasSubCat);
}
},
...
}
我还做了一个简化的工作fiddle ,你可以看看。
关于javascript - Vue 2组件 Prop 得到错误的值,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/45718626/