希望推断Vue中已存在的JSON搜索/过滤/匹配功能,该功能可用于计算函数。这是我的情况。
我有一个本地JSON文件(简称为 ):
更新了JSON以反映最新进展
{
"examplejson": [
{
"section_title": "title 1",
"section_category": "category1",
"items": [
{
"category": "category1",
"title": "item title 1",
"url": "url 1",
"description": "Etiam turpis ipsum, gravida a odio ac, sollicitudin egestas tortor.",
"footnote": "footnote 1"
},
{
"category": "category1",
"title": "item title 2",
"url": "url 2",
"description": "Suspendisse consectetur lacus sed maximus consectetur. Etiam nunc magna, fringilla.",
"footnote": "footnote 2"
}
]
},
{
"section_title": "title 2",
"section_category": "category2",
"items": [
{
"category": "category2",
"title": "title 3",
"url": "url 3",
"description": "Donec venenatis justo at ligula dictum tempus. In euismod nulla.",
"footnote": "footnote 3"
},
{
"category": "category2",
"title": "title 4",
"url": "url 4",
"description": "Cras dui felis, pulvinar vel elit quis, imperdiet sollicitudin massa.",
"footnote": "footnote 4"
}
]
}
]
}
这里是我的Vue组件:
import Vue from 'vue';
import axios from 'axios';
Vue.component('searchableList', {
template: `
<!-- Searchable List Component -->
<div v-cloak>
<label class="search-bar">
<input type="text" class="search__input" v-model="searchString" placeholder="Search...">
</label>
<div class="searchable-content">
<ul class="list">
<li :class="section.section_category + '-section'" v-for="section in filteredList" :key="section.section_title">
<h3 class="section-title">{{ section.section_title }}</h3>
<ul :class="section.section_category + '-section-list'">
<li v-for="item in section.items">
<a :href="item.url">{{ item.title }}</a>
<p>{{ item.description }}</p>
<p class="note">{{ item.footnote }}</p>
</li>
</ul>
</li>
</ul>
</div>
</div>
`
//other items listed below are contained within this component but I separated into individual segments for clear explanation
});
组件数据('componentLoaded'标志可消除计算属性与axios.get方法之间的竞争条件):
data() {
return {
componentLoaded: false,
list: [],
searchString: ''
}
},
// mounted lifecycle hook:
mounted() {
this.getListData();
}
// Axios JSON localized JSON get method:
methods: {
getListData() {
var self = this;
const url = '/path/to/localized/list.json';
axios.get(url)
.then(response => {
self.list = response.data.examplejson;
})
.then(function() {
self.componentLoaded = true;
console.log("content loaded");
})
.catch(error => {
console.log("The file:" + ` "${url}" ` + "does not exist or path/filename is incorrect.");
});
}
},
// Computed filtered list property (this is where im having trouble):
computed: {
filteredList: function() {
let self = this;
if (!self.componentLoaded) {
return null;
}
else {
console.log("list loaded successfully");
return self.list;
}
}
}
DOM中的组件注入点(有条件确定页面中是否存在类,需要单独的页面DOM控制,选择没有全局注入点):
if (document.getElementsByClassName("my-list")[0]){
new Vue({
el: ".my-list"
});
}
HTML:
<div class="container">
<div class="my-list">
<searchable-list></searchable-list>
</div>
</div>
我的一般问题是我的过滤器函数(filteredList)和内容呈现(getListData())变得过于复杂,因此我的搜索过滤不起作用,或者我只是没有正确构建我的搜索过滤器,因为我不完全了解我的JSON数组。这就是我需要的帮助。
预期行为的简单说明:
为列表创建空数组。创建用于搜索查询的空字符串。为axios请求和计算的属性注入之间的竞争条件创建标志,并将其设置为false。
Component通过向JSON(axios.get())发出请求,并将该axios.get()请求的响应分配给本地JSON数据,从而基于本地JSON文件数据呈现嵌套对象(“项目”)列表。我的数据()中的空列表数组。然后,在完成axios请求并将其分配给空数组之后,将标志设置为true。
然后,基于标志是否为true或false,将具有返回的新形成的JSON数据的列表数组通过filteredList的计算属性并将其分配到最高级别的v-for循环中注入到vue组件中(以及随后的嵌套v-for循环(用于其余嵌套内容)。
帮助区域
我要挂断电话的地方是我需要根据查询字符串('searchString')过滤(.filter()函数)内容的搜索输入,然后(我认为我需要方法是:根据匹配(.match()函数)将JSON对象重新呈现给查询字符串。我只需要过滤每个部分中的“项目”数组(并可能返回适用的section_title)。
似乎计算属性上的基本过滤器功能以及将所有匹配项返回到searchString数据查询均无法正常工作。我一直在尝试如下操作:
computed: {
filteredList: function() {
let self = this;
if (!self.componentLoaded) {
return null;
}
else {
let listData = self.list;
//-- new search code --//
let searchItem = listData.section.items;
return calcData.filter((searchItem) => {
return searchItem.title.toLowerCase().match(this.searchString.toLowerCase());
});
//-----//
}
}
}
或更坚固的东西:
computed: {
filteredList: function() {
let self = this;
if (!self.componentLoaded) {
return null;
}
else {
let listData = self.list;
//-- new search code --//
let searchItem = listData.section.items;
let searchTerm = (this.searchString || "").toLowerCase();
return listData.filter(function(searchItem) {
let title = (searchItem.title || "").toLowerCase();
let description = (searchItem.description || "").toLowerCase();
let footnote = (searchItem.footnote || "").toLowerCase();
return title.indexOf(searchTerm) > -1 || description.indexOf(searchTerm) > -1 || footnote.indexOf(searchTerm) > -1;
});
//-----//
}
}
}
这两个函数在控制台中都返回相同的错误:
TypeError: Cannot read property 'items' of undefined
我可以使用以下命令console.log每个键中的任何/所有项目:
console.log(JSON.stringify(self.list.KEY_1.items));
哪个很棒,但无关紧要。但实际上,这只是确认我的嵌套设置正确(?)。
我在想也许我没有正确地遍历所有初始对象(带有键)的事实。或/也由于我有一个通用的JSON对象(“ examplejson”),其中包含多个子对象(2个具有自定义键的同级对象(“ KEY_1”,“ KEY_2”)),还有其他嵌套对象(“ section_title”), “ section_category”)和另一个嵌套的兄弟对象(“ items”),其中包含对象数组,这可能导致我的“简单”调用实际上需要更复杂的标识/操作顺序,因此需要更多复杂/健壮的过滤机制?
或者还是因为比赛条件? (我对此表示怀疑,因为控制台日志显示首先发出axios.get()请求,然后在将标志设置为true时运行条件运算的函数)。
或者也许是完全不同的东西,我什至没有注意到。
对于方向或我在做对/错的任何帮助或澄清,我们将不胜感激。我对Vue还是很陌生,但仍然想弄清楚。预先感谢。
***** UPDATE *****
我现在可以通过删除键(“ KEY_1”,“ KEY_2”)并将“ examplejson”对象转换为数组来成功过滤基于“ section_title”的结果(示例中已进行了更新) )。我可以定位section_title并返回包含“ section_title”的整个对象,其中还包含“ items”数组。
*****更新了仅适用于“ section_title”定位**的计算功能**
computed: {
filteredList: function(){
let self = this;
if(! self.componentLoaded) {
return null;
} else {
let listData = self.list;
//-- new working search code for section objects ONLY --//
let searchItem = listData.section;
return listData.filter((searchItem) => {
return searchItem.section_title.match(this.searchString);
});
//-----//
}
}
}
现在的问题是,除了定位“ section_title”字符串外,我还需要更深入一层并定位items
数组中的内容。只是将.items
附加到searchItem
变量中,使其读取let searchItem = listData.section.item;
或let searchItem = listData.section.items;
不起作用并返回Cannot read property 'item' of undefined
,所以我不确定如何除了items
以外,还应正确定位section_title
数组中的对象。
任何帮助表示赞赏
答案 0 :(得分:0)
const list = [
{
"section_title": "title 1",
"section_category": "category1",
"items": [
{
"category": "category1",
"title": "item title 1",
"url": "url 1",
"description": "Etiam turpis ipsum, gravida a odio ac, sollicitudin egestas tortor.",
"footnote": "footnote 1"
},
{
"category": "category1",
"title": "item title 2",
"url": "url 2",
"description": "Suspendisse consectetur lacus sed maximus consectetur. Etiam nunc magna, fringilla.",
"footnote": "footnote 2"
}
]
},
{
"section_title": "title 2",
"section_category": "category2",
"items": [
{
"category": "category2",
"title": "title 3",
"url": "url 3",
"description": "Donec venenatis justo at ligula dictum tempus. In euismod nulla.",
"footnote": "footnote 3"
},
{
"category": "category2",
"title": "title 4",
"url": "url 4",
"description": "Cras dui felis, pulvinar vel elit quis, imperdiet sollicitudin massa.",
"footnote": "footnote 4"
}
]
}
];
const searchString = 'item';
const filteredList = list.filter((section) => {
// `section` here is an arbitrary variable name to represent the individual element in the `listData`
console.log('section', section);
// If section_title contains searchString, add the element to the filtered result
if (section.section_title.indexOf(searchString) > -1) {
return true;
}
// section_title does not contain searchString,
// proceed to check for each section.items if they contain searchString
const hasItemContainsSearchString = section.items.some((item) => {
// `item` here represents the individual element of section.items
console.log('item', item);
// Check if the title contains searchString
return item.title.indexOf(searchString) > -1;
});
return hasItemContainsSearchString;
});
console.log('filteredList', filteredList);