AngularJS chaining promises - need to do work before the next 'then' - angularjs

Question

I am working on a promise chain. The first call is an $http call to check if a user exists, and then if it does, theres a bunch of .then() statements that run sequentially.
My question is this.. in that first call, i don't want to return the promise of the $http request because if the user doesn't exist, the results are just an empty array and the promise resolves, thus triggering the next action to look up information about the user. I wrote the following code...
(see the part in comments about being the important part i'm asking about)
$scope.checkIfUserExists = function() {
if (angular.isObject($scope.admin.Inductee.Contactor)) {
var handleFault = function( fault ) {
if (typeof(fault) === 'string') {
switch (fault.toUpperCase()){
case 'NODATA':
// Go ahead an save
$scope.pushInductee();
break;
case 'STATUS':
// just get the 'duplicate records check' sign off of there
// The save button is disabled by the critical error
$scope.hideSave = false;
break;
case 'ASSIGNED':
// just get the 'duplicate records check' sign off of there
// The save button is disabled by the critical error
$scope.hideSave = true;
break;
default:
$log.error(fault);
$location.path('/error/default');
}
} else {
$log.error(fault);
$location.path('/error/default');
}
};
$scope.getMatchingIndData()
.then($scope.procBusLogic)
.then($scope.pushInductee)
.catch(handleFault);
}
};
////HERE IS THE IMPORTANT PART I AM ASKING ABOUT
$scope.getMatchingIndData = function() {
var deferred = $q.defer();
var locals = {};
var checkUser = function(dupeJson){
var checkUserDeferred = $q.defer();
// abandoned promise replaced with my own
sttiJoinDataFactory.checkIfUserExistsNurseleader(dupeJson)
.then(function(results) {
var data = results.data;
if (angular.isArray(data) && data.length > 0){
var highestMatch = data[0];
for (var i = 0; i < data.length; i++) {
if (parseInt(data[i].Score) > parseInt(highestMatch.Score)) {
highestMatch = data[i];
}
}
checkUserDeferred.resolve(highestMatch);
} else {
// Reject the 'overall' promise here
// to effectively break the chain
return deferred.reject('NODATA');
}
})
.catch(function(fault) {
// Any other failure should break the chain
// of http requests at this point
return deferred.reject(fault);
});
return checkUserDeferred.promise;
},
loadindividual = function (highestMatch) {
return $http stuff about the highestmatch
// set data in locals
},
parallelLoadStatusAndInducteeData = function(individual) {
return another $http promise based on the last then()
// set data in locals
},
loadCeremonyData = function (inductees){
return another $http promise based on the last call then() // set data in locals
},
reportProblems = function( fault ) {
deferred.reject(fault);
};
checkUser($scope.generateDupJson())
.then(loadindividual, reportProblems)
.then(parallelLoadStatusAndInducteeData, reportProblems)
.then(loadCeremonyData, reportProblems)
.then(function() {
deferred.resolve(locals);
})
.catch( reportProblems );
return deferred.promise;
};
Must I take into account the abandoned promise, since I really need to promise to resolve when the data comes back, and i need to reject it if there is NODATA. This is handled in the calling function's chain.
Also, I'm aware of antipatterns here. I'm trying my best to not nest promises, maintain the chain, as well as handle exceptions.

Answer 1

Ok I have a few comments for you:
...
// revert if and return immediately
// to reduce indentation
if (typeof(fault) !== 'string') {
$log.error(fault);
$location.path('/error/default');
return;
}
switch (fault.toUpperCase()) {
...
You don't need deferred objects:
var checkUser = function(dupeJson){
// this is not abandoned because we are returning it
return sttiJoinDataFactory.checkIfUserExistsNurseleader(dupeJson)
.then(function(results) {
var data = results.data;
if (!angular.isArray(data) || data.length <= 0) {
return $q.reject('NODATA');
}
var highestMatch = data.reduce(function (highest, d) {
return parseInt(d.Score) > parseInt(highest.Score) ?
d : highest;
}, data[0]);
return highestMatch;
}); // you don't need catch here if you're gonna reject it again
}
...
checkUser(...)
// loadIndividual will be called
// after everything inside checkUser resolves
// so you will have your highestMatch
.then(loadIndividual)
.then(parallelLoadStatusAndInducteeData)
.then(loadCeremonyData)
// you don't need to repeat reportProblems, just catch in the end
// if anything rejects prior to this point
// reportProblems will be called
.catch(reportProblems)
...