I have this problem with kinvey backend,
I'm trying to fetch data from my collection but it doesn't work for me. here is my code :
var query = new $kinvey.Query();
query.equalTo('_id', '5909e8084c68b1ef74fa4efc');
var dataStore = $kinvey.DataStore.collection('User1Bases', $kinvey.DataStoreType.Network);
var stream = dataStore.find(query);
stream.subscribe(function onNext(entity) {
// ...
}, function onError(error) {
// ...
}, function onComplete() {
//...
});
Can you help me please
If you let run the code you have posted then consider four things:
Make sure you have Kinvey implemented:
<script src="https://da189i1jfloii.cloudfront.net/js/kinvey-html5-sdk-3.10.2.min.js"></script>
Make sure you have initialized the Kinvey service before:
// Values shown in your Kinvey console
Kinvey.init({
appKey: '<your_appKey>',
appSecret: 'your_appSecret'
});
Make sure you are logged in with a user that has the rights to read your collection (should be fine using the All Users role (default)):
var promise = Kinvey.User.login('<username>', '<password>')
.then(function() {
console.log ("You are logged in");
})
.catch(function(error) {
console.log (error);
});
Output the return result to see whats coming back. To make sure you do the query AFTER successful login, paste you query inside the .then function of login.
I'm not sure if your query is valid unter 3.x since a lot has changed and I'm not working with older Kinvey versions.
So that all together would look like this:
// Initialize Kinvey
Kinvey.init({
appKey: '<your_appKey>',
appSecret: 'your_appSecret'
});
// Login with already registered user
var promise = Kinvey.User.login('<username>', '<password>')
.then(function() {
console.log ("You are logged in");
// Your query
var query = new $kinvey.Query();
query.equalTo('_id', '5909e8084c68b1ef74fa4efc');
var dataStore = $kinvey.DataStore.collection('User1Bases', $kinvey.DataStoreType.Network);
var stream = dataStore.find(query);
stream.subscribe(function onNext(entity) {
// Output of returning result
console.log (entity);
// ...
}, function onError(error) {
// ...
}, function onComplete() {
//...
});
})
.catch(function(error) {
console.log (error);
});
There are now three return sets possible:
Nothing (as you say) -> Something missing/wrong in the code (compare yours with mine)
Empty array: Your query didn't find anything, adapt the search value(s)
One or more entries in the array -> All fine, what you were looking for!
Hope that helps!
When querying by _id there is a built in method: http://devcenter.kinvey.com/angular/guides/datastore#FetchingbyId
Try switching to var stream = dataStore.findById('entity-id');
Also check to make sure you don't have any preFetch or postFetch BL that is interfering with the query.
Related
I'm new to both react and firebase. I'm trying to get a string of file names (just as a continuous string for right now) from a particular folder in the firebase storage bucket. My code is as follows:
getFilesList(){
var toReturn="";
toReturn+="Testing";
var storage = firebase.app().storage(".....");
var storageRef = storage.ref();
var listRef = storageRef.child("/slides/1HdDPbTarLBxzllDlA3H/Lecture1/");
listRef.listAll().then(function(result) {
result.items.forEach(function(imageRef) {
toReturn+=this.getImageString(imageRef);
});
}).catch(function(error) {
toReturn+="error1";
});
return toReturn;
}
getImageString(imageRef) {
var toReturn="T1";
imageRef.getDownloadURL().then(function(url) {
var toReturn=url.toString();
}).catch(function(error) {
toReturn+="error2";
});
return toReturn;
}
I'm not getting any errors, but the return string is blank (aside from the 'Testing' prefix). The folder has about 20 jpg files, but it seems as though it isn't seeing that they are there. I did some research online about it, but I'm still not sure why my code isn't working. Please help me to know why this isn't working?
Thank you,
Jared
This isn't a problem with your framework, it's a problem with asynchronous code.
See, toReturn will eventually update with the results of that function call. The problem is that the caller of this function receives the array immediately, before any of the code in .then has a chance to touch it.
Even if the promise resolves instantly, the code above it will have already executed. Promises get put on a queue where the top item only executes after the current synchronous code has finished.
What getFilesList needs to do is return a Promise that the caller can then attach to in order to specify its own behaviour:
getFilesList(){
var toReturn="";
toReturn+="Testing";
var storage = firebase.app().storage(".....");
var storageRef = storage.ref();
var listRef = storageRef.child("/slides/1HdDPbTarLBxzllDlA3H/Lecture1/");
listRef.listAll().then(function(result) {
result.items.forEach(function(imageRef) {
toReturn+=this.getImageString(imageRef);
});
return toReturn;
}).catch(function(error) {
toReturn+="error1";
return toReturn;
});
And in the caller:
getFilesList.then(filesList => console.log(filesList))
Got the following code:
On AngularJS client:
var getDocs = function() {
return $http.get('/api/docs/list')
.then(function(result) {
return result.data; // bookmark1 line
});
}
On Node.Js BE:
function getDocs() {
return Doc.find({}).exec()
.then(function success(docs) {
return res.send(docs);
});
}
Works perfectly.
When I change the first line in getDocs() to
return Doc.find({}).select('-field1 -field2').exec()
I see the docs after the query execution without the fields (as expected) but for some reason The http is pending and chrome debugger is not stopping on the success callback of the client (bookmark1 line).
Edit:
Changed to
return Cv.find({}).select('-field1 -field2').exec(function success(err, cvs) {
return res.send(cvs);
});
Got the following error in client:
Solution:
Well It turn out I had another field which depends on field1
docSchema.virtual('field3').get(function () {
return this.field1.toString("base64");
});
It fails and for some reason it didnt appear on my IDE.
I Added a null check and that solve the problem.
Not sure if I should remove this question or maybe it has value for other people. Feel free to say what you think.
I am making $http request to multiple environment and processing after I get all the responses. I am using the code below:
$q.all(Object.keys($rootScope.envs).map(request)).then(function(res){
var results = {};
for (var env in res) {
results[env] = res[env].data;
}
}, function(err){
console.error(err);
});
function request(env) {
return $http.get(callService.getDomainUrl()+'/'+$rootScope.envs[env]+ '/hosts.json');
}
The above code works fine, but the results object looks like below:
{
0: {data:{}},
1: {data:{}},
2: {data:{}},
3: {data:{}}
}
I want the corresponding response for each key and the results should be like
{
env1: {data:{//data for env1}},
env2: {data:{//data for env2}},
env3: {data:{//data for env3}},
env4: {data:{//data for env4}},
}
How to map the corresponding response to the key? Please let me know how to get this as this is asynchronous request. Should I have something from the API to know which env the API is coming from?
I think the simplest way would be to push the result handling into the request function, that way you still have the 'env' value in scope.
var results = {};
$q.all(Object.keys($rootScope.envs).map(request)).then(function(res){
// Do something with 'results' here.
}, function(err){
console.error(err);
});
function request(env) {
return $http.get(callService.getDomainUrl()+'/'+$rootScope.envs[env]+ '/hosts.json')
.then(function(res) { results[env] = res.data; return env; });
}
Another option would be to replace my return env with return [env, res.data] and then you can go back to creating the results object as in your original code.
The important thing here is to remember you can handle the $http.get promises individually as well as using the promises from the call to then in $q.all.
I'm working with some arrays in node and I want to send if as one JSON object to the front-end. I use express to do this. I have a model called User where I find users based on their email. That email is provided in an array. I do get the user object but I can't create one JSON object out of them!
I have tried some middleware but that didn't give me any result! https://www.npmjs.com/package/node.extend
var users = {};
for (var i = 0; i <emails.length; i++) {
User.findOne({
'email': project.students[i]
}, function (err, user) {
if (err) {
res.send(err);
}
// Fill the users object with each user found based on the email
});
}
console.log(users); // Should be one JSONObject
Thanks for the help!
You should be able to do this in a single query. It looks like you're using mongoose, so try something like this:
User.find({ email: { $in: emails } }, function(err, results) {
if (err) return res.send(err);
res.send(results);
});
It's also worth noting that javascript is single threaded. This means that a lot of operations happen asynchronously, meaning you have to wait for the operation to get done before you can move on. Your console logging statement above doesn't wait for the database operation to complete. You have to wait for the callback function to execute.
UPDATE: Also just noticed that you are looping over emails but then using project.students[i] within each iteration. I can't see the rest of your code, but this is just buggy code. You should be either looping over project.students or using emails[i] within each iteration.
UPDATE 2: It appears that you are wanting to send more than just an array of user with the response. So the first goal is to use a single query using the $in operator (see example above - you should be able to pass a list of emails to mongoose). Anything mongo-related, you always want to reduce the amount of queries to the database if you care at all about performance. The second task is to reformat your users and other data accordingly:
var finalResponse = { token: "12341234", users: null };
User.find({ email: { $in: emails } }, function(err, results) {
if (err) return res.send(err);
if (!results.length) return res.send(finalResponse);
// OPTION 1: Array of users (recommended)
finalResponse.users = results;
// OPTION 2: users object, keyed by the users email
finalResponse.users = {};
results.forEach(function(user) {
finalResponse.users[user.email] = user;
});
// FINALLY, send the response
resp.send(finalResponse);
});
In my angular app I want to make changes to several locations in my firebase with a mix of transactions and set. I have written a promise chain with a little help. Now I need to handle any errors that may occur.
In the event of an error on any of the promises I would want to roll back any changes made in firebase (the successful promises) and alert the user to the failure.
Current code below
$scope.addNewPost = function() {
var refPosts = new Firebase(FBURL).child('/posts').push();
// Get tags into array for incrementing counters
var tags = $scope.post.tags.split(', ');
var allPromises = [];
// Iterate through tags and set promises for transactions to increment tag count
angular.forEach(tags, function(value, index){
var dfd = $q.defer();
var refTag = new Firebase(FBURL).child('/tags/' + value);
refTag.transaction( function (current_value) {
return current_value + 1;
}, function(error, committed, snapshot) {
if (committed) {
dfd.resolve( snapshot );
} else {
dfd.reject( error );
}
});
allPromises.push( dfd.promise );
});
// Add promise for setting the post data
var dfd = $q.defer();
refPosts.set( $scope.post, function (error) {
if (error) {
dfd.reject(error);
} else {
dfd.resolve('post recorded');
}
});
allPromises.push( dfd.promise );
$q.all( allPromises ).then(
function () {
$scope.reset(); // or redirect to post
},
function (error) {
// error handling goes here how would I
// roll back any data written to firebase
alert('Error: something went wrong your post has not been created.');
}
);
};
So what I need to know is how do I roll back any changes that happen to my firebase data in the event that one of these promises fail. There could be any number of updates happening in firebase. (for example: 3 tags being incremented via transaction and the post data being set)
How would I write the failure function to calculate what was successful and undo it? If this is this even possible.
--------------- sub question from original post has been solved ---------------
Also how do you force errors? I've tried setting a variable like below but it doesn't seem to work, is there something wrong with my .then?
refPosts.set( $scope.post, function (error) {
var forceError = true;
if (forceError) {
dfd.reject(forceError);
} else {
dfd.resolve('post recorded');
}
allPromises.push( dfd.promise );
});
There are two instances of this line, and they are both in the wrong place:
allPromises.push( dfd.promise );
In the first block, it should be in the last statement in the forEach callback, not in the transaction callback.
In the second block, it should be after the call to set(), not in the callback.
The way your code is written now, $q.all() is getting an empty array of promises. That could also be what's interfering with the forceError test you're attempting.