尝试在AngularJS(1.6)中获取嵌套的异步REST请求,然后在完成所有请求后执行代码。
我尝试使用$q.all
,但似乎这不会考虑内部请求(插曲集)。
如何修改以下示例,以便在完成所有请求后执行代码?
// foreach series --> load series details & seasons, foreach season --> load episodes
// when all requests are completed: do something
var requests = []
// e.g. series = [1]
series.forEach(function(seriesId) {
requests.push(loadSeriesDetails(seriesId).then(function(data) {
console.log("received details for series "+seriesId)
// e.g. {id:1, title:"show 1"}
}))
requests.push(loadSeasons(seriesId).then(function (data) {
console.log("received seasons for series "+seriesId+": ", data.seasons.length)
// e.g. [{id:11, title:"season 1"}, {id:12, title:"season 2"}]
data.seasons.map(function(e) {return e.id}).forEach(function(seasonId) {
requests.push(loadEpisodes(seasonId).then(function (data) {
console.log("received episodes for season "+seasonId+": ", data.episodes.length)
// e.g.
// season 11: [{id:111, title:"episode 1-1-1"}, {id:112, title:"episode 1-1-2"}, {id:113, title:"episode 1-1-3"}]
// season 12: [{id:121, title:"episode 1-2-1"}, {id:122, title:"episode 1-2-2"}]
}))
})
}))
})
$q.all(requests).then(function(result) {
console.log("*** all requests completed ***")
console.log(result.length)
})
上面的示例将返回2(1x loadSeriesDetails
,1x loadSeasons
)而不是4(1x loadSeriesDetails
,1x loadSeasons
,2x loadEpisodes
)。
连连呢?提前谢谢!
更新:每个请求函数都是:
loadSeriesDetails = function(id) {
url = "..."+id
return $http.get(url).then(
function (result) {
return result.data
}, function (error) {
̶r̶e̶t̶u̶r̶n̶ ̶e̶r̶r̶o̶r̶
throw error;
});
}
答案 0 :(得分:2)
将requests
数组传递给$q.all
时,应该具有需要解决的所有承诺。目前,您需要在之前的承诺解决后将loadEpisodes
的承诺添加到requests
。
你可以解决这个问题,以便内部部分返回自己的$.q.all
,它将被链接:
var requests = [];
series.forEach(function (seriesId) {
requests.push(loadSeriesDetails(seriesId).then(function (data) {
console.log("received details for series " + seriesId);
return data;
}));
requests.push(loadSeasons(seriesId).then(function (data) {
console.log("received seasons for series " + seriesId + ": ", data.seasons.length);
return loadAllEpisodes(data.seasons);
}));
});
function loadAllEpisodes(seasons) {
var requests = seasons.map(function (season) {
return loadEpisodes(season.id).then(function (data) {
console.log("received episodes for season " + season.id + ": ", data.episodes.length);
return data;
});
});
return $q.all(requests);
}
q.all(requests).then(function(result) {
console.log("*** all requests completed ***");
console.log(result.length);
});
请注意,在您的示例中,您仍然只会在外部$q.all
返回的最终数组中看到2个结果,因为您从每个链的最后一个承诺中获得结果。因此,您可能需要调整返回语句,以便按照您需要的方式对信息进行分组。
答案 1 :(得分:2)
Frank's answer的变体,与原始代码段保持一致。
messages_all