Rxjs Redux Observable:如何在承诺内返回操作?
我有一部史诗:Rxjs Redux Observable:如何在承诺内返回操作?,rxjs,redux-observable,Rxjs,Redux Observable,我有一部史诗: export default function uploadImage(action$, store) { return action$.ofType(userActions.UPLOAD_IMAGE) .mergeMap(action => { ... RNFetchBlob.fs.readFile(uploadUri, 'base64').then(data => { firebaseRef.putString(
export default function uploadImage(action$, store) {
return action$.ofType(userActions.UPLOAD_IMAGE)
.mergeMap(action => {
...
RNFetchBlob.fs.readFile(uploadUri, 'base64').then(data => {
firebaseRef.putString(data).then(snapshot => {
console.log('Uploaded a blob or file!');
return Observable.of(userActions.updateImageURL(snapshot.downloadURL)); //<----------
})
});
})
};
导出默认函数uploadImage(操作$,存储){
返回类型为的action$(userActions.UPLOAD\u图像)
.mergeMap(操作=>{
...
RNFetchBlob.fs.readFile(上传URI,'base64')。然后(数据=>{
firebaseRef.putString(数据)。然后(快照=>{
log('上载了一个blob或文件!');
返回Observable.of(userActions.updateImageURL(snapshot.downloadURL));//可能类似于:
export default function uploadImage(action$, store) {
return action$
.ofType(userActions.UPLOAD_IMAGE)
.mergeMap(action => {
...
Observable
.fromPromise(RNFetchBlob.fs.readFile(uploadUri, 'base64'))
.map(data => {
firebaseRef.putString(data).then(snapshot => {
console.log('Uploaded a blob or file!');
return userActions.updateImageURL(snapshot.downloadURL);
})
});
可能是这样的:
export default function uploadImage(action$, store) {
return action$
.ofType(userActions.UPLOAD_IMAGE)
.mergeMap(action => {
...
Observable
.fromPromise(RNFetchBlob.fs.readFile(uploadUri, 'base64'))
.map(data => {
firebaseRef.putString(data).then(snapshot => {
console.log('Uploaded a blob or file!');
return userActions.updateImageURL(snapshot.downloadURL);
})
});
除了Maxime answer之外,在您的示例中,实际的问题似乎是您没有真正返回承诺!您需要返回承诺,或者切换到使用隐式返回语法作为箭头
export default function uploadImage(action$, store) {
return action$
.ofType(userActions.UPLOAD_IMAGE)
.mergeMap(action => {
return Observable // don't forget to return this chain!
.fromPromise(RNFetchBlob.fs.readFile(uploadUri, 'base64'))
.map(data => {
firebaseRef.putString(data).then(snapshot => {
console.log('Uploaded a blob or file!');
return userActions.updateImageURL(snapshot.downloadURL);
})
});
这是一个非常常见的错误,我们都犯过!此外,为了最大化答案,在您的示例中,实际问题似乎是您没有真正返回承诺!您需要返回承诺或切换到使用隐式返回语法来返回箭头
export default function uploadImage(action$, store) {
return action$
.ofType(userActions.UPLOAD_IMAGE)
.mergeMap(action => {
return Observable // don't forget to return this chain!
.fromPromise(RNFetchBlob.fs.readFile(uploadUri, 'base64'))
.map(data => {
firebaseRef.putString(data).then(snapshot => {
console.log('Uploaded a blob or file!');
return userActions.updateImageURL(snapshot.downloadURL);
})
});
这是一个非常常见的错误,我们都犯过!hey@Maxime!我会不会只嵌套可观察的。fromPromise
如果我有多个依赖于先前承诺结果的承诺?不,这是承诺(和可观察的)的重点。你可以将它们链接起来:)嘿@Maxime!如果我有多个承诺依赖于之前承诺的结果,我会嵌套可观察的。fromPromise
吗?不,这是承诺(和可观察的)的重点。你可以将它们链接起来:)