从id的数组中获取firestore文档的列表

问题描述 投票:1回答:1

我得到了一个firestore集合,他的一个值是一个文档id的数组,我需要检索集合中的所有项目以及所有存储在数组id中的文档。enter image description here

我的代码。

export const getFeaturedMixes = functions.https.onRequest((request, response) => {
    let result:any[] = []
    featuredMixes.get().then(mixesSnap => {

        mixesSnap.forEach(doc => {
            let docId = doc.id
            let ids = doc.data().tracks

            let resultTracks:any[] = []
            ids.forEach(id => {
                let t = tracksCollection.doc(id.track_id).get()
                resultTracks.push({'id' : id.track_id, 'data': t})
            })
            result.push({'id':docId, 'tracks': resultTracks})
        })
        return result
    })
    .then(results => {
        response.status(200).send(results)
    }).catch(function(error) {
        response.status(400).send(error)
    })
});

我得到了这样的回应:

{
        "id": "Xm4TJAnKcXJAuaZr",
        "tracks": [
            {
                "id": "FG3xXfldeJBbl8PY6",
                "data": {
                    "domain": {
                        "domain": null,
                        "_events": {},
                        "_eventsCount": 1,
                        "members": []
                    }
                }
            },
            {
                "id": "ONRfLIh89amSdcLt",
                "data": {
                    "domain": {
                        "domain": null,
                        "_events": {},
                        "_eventsCount": 1,
                        "members": []
                    }
                }
            }
    ]
}

response doesn't contains document data

javascript typescript firebase google-cloud-firestore async-await
1个回答
0
投票

的结构。get() 方法是异步的,并返回一个 Promise。因此你不能做这样的事情。

 ids.forEach(id => {
      let t = tracksCollection.doc(id.track_id).get()
      resultTracks.push({'id' : id.track_id, 'data': t})
 })

你需要等待Promise方法返回的是... get() 方法解析,以便能够使用 t (这是一个 DocumentSnapshot).

为此,由于你想并行获取多个文档,你需要使用 Promise.all().

下面应该可以做到。需要注意的是,它没有经过测试,还有一部分简单的代码需要你来完成,请看最后的注释。如果你在定稿时遇到一些问题,请把你的新代码补充到你的问题中。

export const getFeaturedMixes = functions.https.onRequest((request, response) => {
    let result: any[] = []

    const docIds = [];

    featuredMixes.get()
        .then(mixesSnap => {


            mixesSnap.forEach(doc => {
                let docId = doc.id
                let ids = doc.data().tracks

                const promises = []

                ids.forEach(id => {
                    docIds.push(docId);
                    promises.push(tracksCollection.doc(id.track_id).get())
                })

            })

            return Promise.all(promises)
        })
        .then(documentSnapshotArray => {

            // Here documentSnapshotArray is an array of DocumentSnapshot corresponding to
            // the data of all the documents with track_ids

            // In addition, docIds is an array of all the ids of the FeaturedMixes document

            // IMPORTANT: These two arrays have the same length and are ordered the same way

            //I let you write the code to generate the object you want to send back to the client: loop over those two arrays in parallel and build your object


            let resultTracks: any[] = []

            documentSnapshotArray.forEach((doc, idx) => {
                // .....
                // Use the idx index to read the two Arrays in parallel

            })

            response.status(200).send(results)

        })
        .catch(function (error) {
            response.status(400).send(error)
        })
});

0
投票

谢谢 Renaud Tarnec!!!!真的很希望你的答案,函数已经在工作了,但是我想返回Promise.all(primises)一些持有Promise.all(primises)的对象。混合 与他的轨道,因为现在很难在然后的函数中建立新的对象,这是我的最终函数

    const mixIDs: any[] = [];
    const mixes:any[] =[]

    featuredMixes.get()
        .then(mixesSnap => {
            const promises:any[] = []

            mixesSnap.forEach(doc => {
                let mixId = doc.id
                let mix = createMix(doc)
                mixes.push(mix)

                doc.data().tracks.forEach(track => {
                    let promise = tracksCollection.doc(track.track_id).get()
                    promises.push(promise)
                    mixIDs.push(mixId)
                })
            })
            return Promise.all(promises)
        })
        .then(tracksSnapshot => {

            let buildedTracks = tracksSnapshot.map((doc, idx) => {
                let mId = mixIDs[idx]
                return createTrack(doc, mId)
            })

            let result = mixes.map(mix => {
                let filterTracks = buildedTracks.filter(x => x.mix_id === mix.doc_id)
                return Object.assign(mix, {'tracks': filterTracks})
            })
            response.status(200).send(result)
        })
        .catch(function (error) {
            response.status(400).send(error)
        })
})
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