I need to push the data into a new array from the database, which will return promise object. 5 times I need to call. So I do it like this.
var items = []; function setData() { facilityAPIs.getAllListItems.get({ listName: "Samples" }). $promise.then(function(data) { alert("1"); for (var j = 0; j < data.items.length; j++) { items.push(data.items[j]); } console.log(items); }).then(function() { facilityAPIs.getAllListItems.get({ listName: "Controls" }). $promise.then(function(data) { alert("2"); for (var j = 0; j < data.items.length; j++) { items.push(data.items[j]); } console.log(items); }); }).then(function() { facilityAPIs.getAllListItems.get({ listName: "FibroBlast" }). $promise.then(function(data) { alert("3"); for (var j = 0; j < data.items.length; j++) { items.push(data.items[j]); } console.log(items); }); }).then(function() { facilityAPIs.getAllListItems.get({ listName: "pBMC" }). $promise.then(function(data) { alert("4"); for (var j = 0; j < data.items.length; j++) { items.push(data.items[j]); } console.log(items); }); }).then(function() { facilityAPIs.getAllListItems.get({ listName: "iPS Cell Lines" }). $promise.then(function(data) { alert("5"); for (var j = 0; j < data.items.length; j++) { items.push(data.items[j]); } console.log(items); }); }); }
But if I want to use items array after all of data are pushed into it, such as call splitData(items). how can I that. Thank you.
So is it something like this?
var items = [];
some_fn(...)
.then(function(data) { [push data to items] })
.then(function() {
some_fn(...).then(function(data) { [push data to items] });
})
.then(function() {
some_fn(...).then(function(data) { [push data to items] });
})
.then(function() {
some_fn(...).then(function(data) { [push data to items] });
})
.then(function() {
some_fn(...).then(function(data) { [push data to items] });
})
.then(function() {
...use items somehow after _all_ data has been pushed to it...
})
If so, then the problem is that this " .then
chain" isn't really a chain: the "top level .then
"s will be executed one after another, but inside each of them you start a new asynchronous operation separately. Each of these will eventually push some data to items, but the end result cannot be captured in the last " .then
".
If you simply attach multiple "fulfilled" callbacks to the same promise, and you don't return a promise from them, they will simply be execute one after the other, when your first promise is fulfilled:
promise
.then(function() { foo; } // will be executed when promise is fulfilled
.then(function() { bar; } // will be executed right after
If you run other async operations in your callbacks, and want to create a chain, you need to return a promise from the callback:
promise
.then(function() { return promise_foo; } // will be executed when promise is fulfilled
.then(function() { return promise_bar; } // will be executed when promise_foo is fulfilled
(For details, see The Promise Resolution Procedure in the spec .)
So the original example could be reorganised like this to create a single chain:
some_fn(...)
.then(function(data) { [push data to items] })
.then(function() {
return some_fn(...).then(function(data) { [push data to items] });
})
.then(function() {
return some_fn(...).then(function(data) { [push data to items] });
})
.then(function() {
return some_fn(...).then(function(data) { [push data to items] });
})
.then(function() {
return some_fn(...).then(function(data) { [push data to items] });
})
.then(function() {
...all operations have finished, you can use items here...
})
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