my problem don't know how know when dynamic promise array has promises resolved.
here example:
var promisearray = []; promisearray.push(new promise(){/*blablabla*/}); promisearray.push(new promise(){/*blablabla*/}); promise.all(promisearray).then(function(){ // executen when 2 promises solved. }); promisearray.push(new promise(){/*blablabla*/}); i have problem here. promise.all behavior executed when previous 2 promises solved, but, before 2 promises solved, third promise added , new 1 won't take in account.
so, need, like: "hey promise.all, have dynamic array check". how can it?
remember example. know can move line promise.all last line, new promises added dynamically when promises solved, , new promises add new promises well, so, it's dynamic array.
the real use case have this:
- i use twitter api check if there new tweets (using search api).
- in case found new tweets, add mongodb (here have promises).
- in case new tweets related user not have in mongodb (here have new promises because have go mongodb check if have user), go twitter api user info (more promise) , add new users mongodb (yes, more promises).
- then, go mongodb insert new values associate new tweets new users (more promises! wiii!).
- when queries mongodb resolved (all selects, updates, inserts), close mongodb connection.
another hard example:
var allpromises = []; allpromises.push(new promise(function(done, fail){ mongodb.connect(function(error){ //because mongodb works callbacks instead of promises if(error) fail(); else ajax.get('/whatever').then(function(){ if (somethinghappens) { allpromises.push(new promise(function(done, fail){ //this promise never take in account // bla bla bla if (somethinghappens) { allpromises.push(new promise(function(done, fail){ //this promise never take in account // bla bla bla })); } else { ajax.get('/whatever/2').then(function(){ if (somethinghappens) { allpromises.push(new promise(function(done, fail){ //this promise never take in account // bla bla bla })); } }); } })); } else { ajax.get('/whatever/2').then(function(){ if (somethinghappens) { allpromises.push(new promise(function(done, fail){ //this promise never take in account // bla bla bla if (somethinghappens) { allpromises.push(new promise(function(done, fail){ //this promise never take in account // bla bla bla })); } else { ajax.get('/whatever/2').then(function(){ if (somethinghappens) { allpromises.push(new promise(function(done, fail){ //this promise never take in account // bla bla bla })); } }); } })); } }); } }); }); })); promise.all(allpromises).then(function(){ // soooo, work done! mongodb.close()! }); so, now, beauty example. need call showalltheinformation function when last (we don't know last) promise called. how do it?:
var name = 'anonimus'; var date = 'we not know'; function userclikonlogin() { $http.get('/login/user/password').then(function(data){ if (data.logguedok) { $http.get('/checkifisadmin').then(function(data){ if (data.yesheisanadmin) { $http.get('/getthenameoftheuser').then(function(data){ if(data.userhasname) { $http.get('/getcurrentdate').then(function(data){ currentdate = data.thenewcurrentdate; }); } }); } }); } }); } function showalltheinformation() { alert('hi ' + name + ' today is:' + date); } here example more context: https://jsfiddle.net/f0a1s79o/2/
there's no way out. have put promises in array before calling promise.all in it. in example presented, that's simple moving last line top.
in case asynchronously filling array, should promise array, , use .then(promise.all.bind(promise)). if don't know when stop adding promises, impossible anyway might never resolved @ all.
regarding "beauty example", want learn magic of chaining. previosly said in comments, have return promise every function in doing asynchronous. indeed, add missing returns:
function userclikonlogin() { return $http.get('/login/user/password').then(function(data){ // ^^^^^^ if (data.logguedok) { return $http.get('/checkifisadmin').then(function(data){ // ^^^^^^ if (data.yesheisanadmin) { return $http.get('/getthenameoftheuser').then(function(data){ // ^^^^^^ if(data.userhasname) { return $http.get('/getcurrentdate').then(function(data){ // ^^^^^^ currentdate = data.thenewcurrentdate; }); } }); } }); } }); } userclikonlogin().then(function showalltheinformation() { // ^^^^^ can chain onto it! alert('hi ' + name + ' today is:' + date); }); there no array of promises here dynamically grows, it's every function returning promise (asynchronous) result of things does.
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