我不确定如何在我的mobx商店中实施承诺。我有两个动作,我想在循环中顺序运行,并确保在运行第二个之前等待第一个完成。这是我的商店代码示例。请询问任何进一步的说明,我一定要加上。我试图将代码简化为我认为找到解决方案所必需的内容。谢谢!
import { observable, action } from 'mobx';
import Store from '../support/store';
class Upload extends Store {
@observable fileList = null; // array of files to be uploaded
@observable processedFile = null; // single file pre-processed for upload
@action processFile(file) {
// takes file from fileList array, 'processes' it and
// places the result in this.processedFile
}
@action post() {
// makes a POST request, uploading this.processedFile
// sets this.processedFile = null
}
@action postFileList() {
// loops over the array this.fileList
// runs this.processFile(file)
// waits until processFile(file) is finished
// runs post()
// waits until post() is finished
// removes file from the this.fileList array
}
}
答案 0 :(得分:0)
如果您在操作中执行异步操作,则需要确保wrap the asynchronously called function in an action as well。
如果postFileList
中没有剩余文件,您可以退出fileList
。
示例强>
class Upload extends Store {
@observable fileList = [];
@observable processedFile = null;
@action processFile(file) {
return new Promise(resolve => {
const file = this.fileList[0];
setTimeout(action(() => {
this.processedFile = file.processed;
resolve();
}), 1000);
});
}
@action post() {
return new Promise(resolve => {
const file = this.processedFile;
setTimeout(action(() => {
this.processedFile = null;
resolve();
}), 1000);
});
}
@action postFileList() {
if (this.fileList.length === 0) {
return;
}
this.processFile()
.then(() => this.post())
.then(action(() => {
this.fileList.shift();
this.postFileList();
}));
}
}