我正在尝试通过名为“事件日期”的元字段对Shopify博客帖子进行排序。我调用我的article.JSON，但它不包含metafields.JSON，因此我必须采用该数组，并通过一个foreach函数将其添加到每篇文章中。
这是设置每篇文章的metafields.json的方式：
$ make
Scanning dependencies of target TestTester
[ 25%] Building CXX object existing_source/CMakeFiles/TestTester.dir/main.cpp.o
[ 50%] Linking CXX executable TestTester
[ 50%] Built target TestTester
Scanning dependencies of target Test_TestTester
[ 75%] Building CXX object new_test_source/CMakeFiles/Test_TestTester.dir/main_test.cpp.o
[100%] Linking CXX executable Test_TestTester
Run tests
Test project /home/imk/develop/so/scrap2/build/new_test_source
Start 1: Test
1/1 Test #1: Test ............................. Passed 0.00 sec
100% tests passed, 0 tests failed out of 1
Total Test time (real) = 0.00 sec
[100%] Built target Test_TestTester
我如何附加以下metafields.JSON：
{
"metafields":[
{
"id":5994805788772,
"namespace":"global",
"key":"Event-Date",
"value":"1549256400",
"value_type":"string",
"description":null,
"owner_id":15977611364,
"created_at":"2019-02-06T18:31:44-05:00",
"updated_at":"2019-02-06T18:31:44-05:00",
"owner_resource":"article"
},
{
"id":5994805821540,
"namespace":"global",
"key":"Event-Time",
"value":"6:00pm - 8:00pm",
"value_type":"string",
"description":null,
"owner_id":15977611364,
"created_at":"2019-02-06T18:31:45-05:00",
"updated_at":"2019-02-06T18:31:45-05:00",
"owner_resource":"article"
},
{
"id":6010564542564,
"namespace":"global",
"key":"Location",
"value":"18th Street Location",
"value_type":"string",
"description":null,
"owner_id":15977611364,
"created_at":"2019-02-07T13:16:05-05:00",
"updated_at":"2019-02-07T14:05:08-05:00",
"owner_resource":"article"
}
]
}
我现在正在尝试删除所有与日期（与当前日期相比）已经过去的日期（“键”：“事件日期”）的文章。我已经看过以下Stack Overflow Post关于在foreach循环中删除对象的信息，但是没有一种解决方案能证明实际上摆脱了所有文章。它会偶尔摆脱所有物体，但有时会留在其中一个物体中。
我也尝试过使用数组过滤器，但是当我使用它时，我得到的只是一个空数组。我已经在此问题上停留了一段时间，因此在解决该问题上的任何帮助将不胜感激。
答案 0 :(得分：0)
您输入的是文章吗？然后您可以忽略使用：
request.onload = function() {
var articleList = request.response;
var articleArray = articleList.articles;
var date = new Date();
var ticks = Math.floor(date.getTime() / 1000);
var count = 0;
articleArray.forEach(function(entry,index, object){
if(entry.'Key' !== 'Event-Date'){
var metaRequest = new XMLHttpRequest();
metaRequest.open('GET', '/admin/blogs/43130421348/articles/'+ entry.id + '/metafields.json');
metaRequest.responseType = 'json';
metaRequest.send();
console.log(index);
metaRequest.onload = function() {
var articleMetaObj = metaRequest.response;
var articleMetaArr = articleMetaObj.metafields;
entry.metafields = articleMetaArr;
var eventDate = entry.metafields[0].value;
}
}
});
答案 1 :(得分：0)
我认为如果等到附加了所有元数据后再完成所有操作，那么最简单的方法就是使用articleArray.filter取出不需要的数据。为此，您有两个选择：
选项1-旧方法（setInterval）
在这里，我们在获取元数据时保持计数，并创建一个间隔来检查它们何时全部完成。完成后，将调用一个函数（完成），该函数可以继续进行处理。
var request = new XMLHttpRequest();
request.open('GET', '/admin/blogs/43130421348/articles.json');
request.responseType = 'json';
request.send();
request.onload = function () {
var articleList = request.response;
var articleArray = articleList.articles;
var date = new Date();
var ticks = Math.floor(date.getTime() / 1000);
var count = 0; //to keep track of how many metafields have been retrieved
var checkInterval = null;
articleArray.forEach(function (entry, index) {
var metaRequest = new XMLHttpRequest();
metaRequest.open('GET', '/admin/blogs/43130421348/articles/' + entry.id + '/metafields.json');
metaRequest.responseType = 'json';
metaRequest.send();
console.log(index);
metaRequest.onload = function () {
var articleMetaObj = metaRequest.response;
var articleMetaArr = articleMetaObj.metafields;
entry.metafields = articleMetaArr;
count++;
};
});
//Function to continue processing
var finish = function () {
articleArray = articleArray.filter(a => new Date(a.metafields[0].value).getTime() < date.getTime());
//Continue on...
};
//Wait until all metafields are retrieved to continue
checkInterval = setInterval(function () {
if (count === articleArray.length - 1) {
clearInterval(checkInterval);
finish();
}
}, 500);
};
选项2-新Razmatazz（承诺和异步/等待）
Promises和async / await允许在处理异步操作时编写一些美观得多的代码。
如果您想使用这些工具，我建议您深入研究文档以使其更加熟悉，但这就是您的任务的样子。
//Functions that return Promises can be awaited...
var get = url => new Promise((resolve, reject) => {
var request = new XMLHttpRequest();
request.open('GET', url);
request.responseType = 'json';
//resolve is called when successful
request.onload = () => resolve(request.response);
//reject is called when there's a problem
request.onerror = err => reject(err);
request.send();
});
//await keyword must appear in an async function
var getArticles = async () => {
var articleList = await get('/admin/blogs/43130421348/articles.json');
return articleList.articles;
};
//Promise.all takes an array of promises and resolves when all of them are finished
//This lets you skip the messy setInterval stuff
var getArticleMetafields = async articles => {
var requests = [];
articles.forEach(a => {
var url = '/admin/blogs/43130421348/articles/' + a.id + '/metafields.json';
var promise = get(url);
requests.push(promise);
});
var responses = await Promise.all(requests);
responses.forEach((response, i) => {
articles[i].metafields = response.metafields;
});
return articles;
};
//Notice the async on the handler
document.addEventListener('DOMContentLoaded', async () => {
var articles = await getArticles();
articles = await getArticleMetafields(articles);
var date = new Date();
articles = articles.filter(a => new Date(a.metafields[0].value) < date);
//Continue...
});
希望这会有所帮助。干杯！