javascript 等到 promise 和嵌套 then 完成
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Wait until promise and nested thens are complete
提问by RolandG
I'm returning a promise from a function like this:
我正在从这样的函数返回一个承诺：
resultPromise = dgps.utils.save(opportunity, '/api/Opportunity/Save', opportunity.dirtyFlag).then(function () {
self.checklist.saveChecklist(opportunity).then(function () {
self.competitor.save(opportunity.selectedCompetitor()).then(function ... etc.
return resultPromise;
Let's say the above function is called save.
假设上面的函数被称为保存。
In the calling function I want to do wait for the entire chain to complete and then do something. My code there looks like this:
在调用函数中，我想等待整个链完成然后做一些事情。我的代码如下所示：
var savePromise = self.save();
savePromise.then(function() {
console.log('aftersave');
});
The result is that 'aftersave' is send to the console while the chain of promises is still running.
结果是在承诺链仍在运行时将“aftersave”发送到控制台。
How can I do something after the whole chain is complete?
整个链条完成后我该怎么做？
回答by Raymond Chen
Instead of nesting the promises, chain them.
不要嵌套承诺，而是将它们链接起来。
resultPromise = dgps.utils.save(opportunity, '/api/Opportunity/Save', opportunity.dirtyFlag).then(function () {
return self.checklist.saveChecklist(opportunity);
}).then(function () {
return self.competitor.save(opportunity.selectedCompetitor());
}).then(function () {
// etc
});
// return a promise which completes when the entire chain completes
return resultPromise;
