如何解决Blaze 模板,遍历字段?
我找不到任何可用于循环遍历名为“week01”、“week02”、“week03”的字段的快捷方式的引用,我可以在其中引用该字段,该字段是包含子字段的对象相同的结构。
我知道每个文档都有 #each,但不知道如何处理每个字段。我有 30 周的字段,想遍历这些字段,然后也引用对象属性。
谁能给我一个提示或可能对我有帮助的在线资源?我是一名 VB/PHP 开发人员,正在开发我的第一个 Meteor 应用程序,并第一次与 Mongo 合作。希望我错过了一些可能的东西。
"personId": "rY7XaJJkrdAWaByQK","week01": {
"date": {
"$date": "2021-04-07T12:00:00.000Z"
},"field1": "chunks as necessary","field2": "readable English","field3": "Contrary to popular belief"
},"week02": {
"date": {
"$date": "2021-04-14T12:00:00.000Z"
},"field1": "consectetur,from","field2": "more recently with desktop","week03": {
"date": {
"$date": "2021-04-21T12:00:00.000Z"
},"field1": "going through","week04": {
"date": {
"$date": "2021-04-28T12:00:00.000Z"
},"field1": "words which don't look","field2": "sure there isn't","week05": {
"date": {
"$date": "2021-05-05T12:00:00.000Z"
},"field1": "only five centuries","field2": "Where can I get some","field3": "infancy. VarIoUs"
}
} ```
解决方法
#each
仅接受数组或游标,因此您需要从对象中提取一个数组。
在 JavaScript 中,您可以从对象(即您的文档)的字段(属性)生成一个数组,并过滤它们以仅包含在其属性名称(键)中包含 week
的那些。然后你可以通过 helper 返回它们:
const document = {
"personId": "rY7XaJJkrdAWaByQK","week01": {
"date": {
"$date": "2021-04-07T12:00:00.000Z"
},"field1": "chunks as necessary","field2": "readable English","field3": "Contrary to popular belief"
},"week02": {
"date": {
"$date": "2021-04-14T12:00:00.000Z"
},"field1": "consectetur,from","field2": "more recently with desktop","week03": {
"date": {
"$date": "2021-04-21T12:00:00.000Z"
},"field1": "going through","week04": {
"date": {
"$date": "2021-04-28T12:00:00.000Z"
},"field1": "words which don't look","field2": "sure there isn't","week05": {
"date": {
"$date": "2021-05-05T12:00:00.000Z"
},"field1": "only five centuries","field2": "Where can I get some","field3": "infancy. Various"
}
}
const weeks = Object.entries(document) // will be an array of key/value pairs
.filter(([key,value]) => key.includes('week')) // only use week fields
.map(([key,value]) => value) // only use the value
Template.helpers({
allWeeks () {
return weeks
}
})
然后您可以通过 {{#each week in allWeeks}}
对其进行迭代。
注意:这有点低效,因为在每次重绘时它都会运行上面的代码。您将引入一个 ReactiveVar 或 ReactiveDict 并将 week
保存在那里并从这个反应源返回值:
const state = new ReactiveDict()
const weeks = Object.entries(document) // will be an array of key/value pairs
.filter(([key,value]) => value) // only use the value
state.set({ weeks })
Template.helpers({
allWeeks () {
return state.get('weeks')
}
})
阅读:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/entries
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map
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