Getting All Users Uid from Firebase / Flutter/Dart - database

My application is kind of a poll application. So the admin asks a question, and users respond to that question, and every data is stored in Firestore. In the admin page, the admin can see the question that he/she created, and when the admin clicks the question, he/she can see the answers of users to this question.
On the answers page, I am trying to reach every user's uid but I couldn't achieve this. I can print them but I can't use them in a way. I think I make some mistakes with Firebase functions.
This is an example of a method that I am trying to return the list includes of the specific question. But this function doesn't return anything.
List getUserIDData() {
List<String> growableList = [];
List<String> userAnswerList = [];
String adminQuestion = "What is the reason of life?";
Firestore.instance.collection("user").getDocuments().then((snapshot) {
snapshot.documents.forEach((element) {
growableList.add(element.documentID);
});
for (int i = 0; i < growableList.length; i++) {
Firestore.instance
.collection("user")
.document(growableList[i])
.collection("answers")
.where("adminQuestion", isEqualTo: adminQuestion)
.getDocuments()
.then((snapshot) {
snapshot.documents.forEach((element) {
userAnswerList.add(element["userAnswer"]);
});
});
print(i);
}
});
return growableList;
}
I also tried something with StreamBuilder, but still, after Firestore.instance, everything is deleted automatically. In Firestore, everything looks good, but after it finished growableList doesn't stay the same and this function returns null.
Do you have any suggestions to do so?

From what I can see you are using a very old version of FlutterFire, for example the following has been changed:
BREAKING: getDocuments/get has been updated to accept an instance of GetOptions (see below).
DEPRECATED: documents has been deprecated in favor of docs.
DEPRECATED: documentID has been deprecated in favor of id.
You might want to migrate to a newer version.
With snapshot.documents you get a List<QueryDocumentSnapshot<T>> according to the documentation. So I looked at the QueryDocumentSnapshot and was surprised that you apply element["userAnswer"] directly to it. According to the documentation you have to use element.data() to get the data.
If that doesn't help I would need more information in the form of output what's behind the element variables.

Related

SalesForce query returns results in Query Editor, but returns null from APEX code in Lightning component

I'm completely new to SalesForce and have inherited a report that's not working. Please excuse any incorrect terminology, since I'm learning about all this as I go. The report has three prompts: states, years, and members. All dropdowns are supposed to populate with data returned from functions in an APEX class. State, which populates from a picklist, and years, which is populated with a loop, work fine. Members, which populates from a SQL query, returns nothing. If I run the report without any prompts selected (which should return an unfiltered list of results from a SQL query), it also returns nothing. Both of the SQL queries return data when I execute them directly in the query editor in the developer console, but they return nothing when called from the APEX functions.
Here's the initialization code from the Lightning controller:
doInit: function (component, event, helper) {
var action = component.get('c.getTrcAccounts');
action.setCallback(this, function (response) {
var state = response.getState();
if (state === 'SUCCESS' && component.isValid()) {
component.set('v.trcAccList', response.getReturnValue());
}
helper.getLocationState(component, event);
helper.getYear(component, event);
});
$A.enqueueAction(action);
},
Here are the two helper functions referenced in that code:
getLocationState: function (component, event) {
var action = component.get('c.getLocationState');
action.setCallback(this, function (response) {
var state = response.getState();
if (state === 'SUCCESS') {
component.set('v.LocationStateList', response.getReturnValue());
}
});
$A.enqueueAction(action);
},
getYear: function (component, event) {
var action = component.get('c.yearsOptions');
action.setCallback(this, function (response) {
var state = response.getState();
if (state === 'SUCCESS') {
component.set('v.LocationYearList', response.getReturnValue());
}
});
$A.enqueueAction(action);
}
Here is the code from the APEX class that returns the data for those three prompts:
Global class DataTableLocations {
#AuraEnabled
Global static List<TRC_Account__c> getTrcAccounts(){
set<string> trcAccountSet = new set<string>();
List<TRC_Account__c> traccList = new List<TRC_Account__c>();
for(TRC_Account__c trcacc : [SELECT Id, Name from TRC_Account__c WHERE TRC_Member__c = True order by Name limit 50000]){
if(!trcAccountSet.contains(trcacc.Name)){
trcAccountSet.add(trcacc.Name);
traccList.add(trcacc);
}
}
if(traccList.size()>0){
return traccList;
}
else{
return null;
}
}
#AuraEnabled
Global static List<string> getLocationState(){
List<string> options = new List<string>();
//options.add(new SelectOption('SelectAll', 'Select All'));
for( Schema.PicklistEntry f : Location__c.Physical_Address_State__c.getDescribe().getPicklistValues()) {
options.add(f.getValue());
}
return options;
}
#AuraEnabled
Global static List<string> yearsOptions() {
List<string> options = new List<string>();
date OldDate= date.today().addYears(-18);
integer oldyear=OldDate.year();
for( integer i=0; i<19 ;i++) {
options.add(string.valueOf(oldyear));
oldyear++;
}
return options;
}
}
If I run SELECT Id, Name from TRC_Account__c WHERE TRC_Member__c = True order by Name limit 50000 directly in the query editor window in the developer console, I get 7 results. However, if I output the response.getReturnValue() for getTrcAccounts in the doInit function, it's null.
Any help is greatly appreciated, as we're in a bit of a time crunch in conjunction with a site redesign. I'm told these reports were working at one point, but no one knows when they stopped working, and we inherited this code from a different company that did the original development. Thank you!
UPDATE:
In case it helps, this is the code in the lightning app that I think is used on the public page:
<aura:application extends="ltng:outApp" access="GLOBAL" implements="ltng:allowGuestAccess">
<aura:dependency resource="c:SearchBinReceiptsByYear"/>
</aura:application>
Edit
Right, it's a public page, it's called "Salesforce Sites". It's exposed to whole world without having to log in. These have special security in place because most of the time you don't want to expose data like that. At best you'd display contact us form, maybe some documents to download, product catalog... It's all very locked down, default is to ban everything and then admin decides what's allowed. It's bit unusual to have a Visualforce page + Aura component but ok, it happens.
You (and any other internal user) can see the results if you'd access this page from within salesforce. Something like https://mydomain.my.salesforce.com/apex/SearchBinReceiptsByYear and for you the page will work fine, "just" not outside of salesforce.
When exposed like that on the web - there's no logged in user. There's special "[Site Name] Guest User", you can see them if you search "Sites" in Setup. It has a special profile, also with [Site Name] in it. And nasty thing is - it doesn't show on the list of Users or Profiles.
Your code broke when Salesforce (auto)activated a critical update. Probably this one: https://releasenotes.docs.salesforce.com/en-us/spring20/release-notes/rn_networks_secure_perms_guests.htm There are some good resources on the net if you Google "Secure Object Permissions for Guest Users", for example https://katiekodes.com/salesforce-spring-20-guest-user/
Ask your system administrator colleague or read up a bit about sharing rules.
You'll have to go to Setup -> Sharing Rules. There's a checkbox that caused your stuff to break and you can't untick it.
Scroll down to your TRC Account object and hit "New". You'll need to create something like this, but with your criteria (TRC Member equals true)
Save, wait a bit (it might take a while to recalculate the sharing, you'll get an email) and try the page.
If it still doesn't work you'll have to check the Guest user's profile, it might need permissions to Read TRC Accounts and their Name field.
If it's Salesforce Sites - try this to find it: https://help.salesforce.com/articleView?id=000334554&type=1&mode=1
If it's a Customer Portal, Community, Digital Experience (they renamed the product few times) - try with https://help.salesforce.com/articleView?id=sf.rss_config_guest_user_profile.htm&type=5
Original answer
It looks like it's running OK because accounts (members?) are fetched first and in that fetch's callback (what to do when data comes back from server) you have helper.getLocationState, helper.getYear. And you wrote that these populate OK. It's not the best performance code but it should get the job done.
In no specific order...
Does the whole thing work OK for sysadmins? Or is it broken for everybody? If it works for sysadmins it might be something to do with sharing, your sysadmin should know (Setup -> Sharing settings is where you control who can see what. Maybe "mortals" are not allowed to see any data? Typically sysadmins bypass it. As a quick & dirty test you can modify the class definition to global without sharing class DataTableLocations but it's a really ugly hack.
What happens if you open DeveloperConsole (upper right corner) while running this component, do you see any errors in the logs? What happens if in the console you go Debug -> Open ExecuteAnonymous and run this piece of code:
System.debug(DataTableLocations.getTrcAccounts());
Does it return something? Throw error?
You can go to Setup -> Debug Mode, tick the checkbox next to your user and save. This slows the system down a bit but lets you debug the javascript better. You can then sprinkle some debugger; or console.log statements in the source code and view what happens in your browser's console (Ctrl+Shift+J in Chrome, Ctrl+Shift+I in firefox). For example
action.setCallback(this, function (response) {
var state = response.getState();
debugger;
console.log(state);
console.log(component.isValid());
console.table(response.getReturnValue());
if (state === 'SUCCESS' && component.isValid()) {
component.set('v.trcAccList', response.getReturnValue());
}
console.log(component.get('v.trcAccList'));
debugger;
helper.getLocationState(component, event);
helper.getYear(component, event);
});
How's the trcAccList variable actually used in the "cmp" file, in the HTML-like file? Maybe it's being set all right and contains 7 records but it's not displayed right?

Ways to access firebase storage (photos) via web app

I'm confused as to the appropriate way to access a bunch of images stored in Firebase storage with a react redux firebase web app. In short, I'd love to get a walkthrough of, once a photo has been uploaded to firebase storage, how you'd go about linking it to a firebase db (like what exactly from the snapshot returned you'd store), then access it (if it's not just <img src={data.downloadURL} />), and also how you'd handle (if necessary) updating that link when the photo gets overwritten. If you can answer that, feel free to skip the rest of this...
Two options I came across are either
store the full URL in my firebase DB, or
store something less, like the path within the bucket, then call downloadURL() for every photo... which seems like a lot of unnecessary traffic, no?
My db structure at the moment is like so:
{
<someProjectId>: {
imgs: {
<someAutoGenId>: {
"name":"photo1.jpg",
"url":"https://<bucket, path, etc>token=<token>"
},
...
},
<otherProjectDetails>: "",
...
},
...
}
Going forward with that structure and the first idea listed, I ran into trouble when a photo was overwritten, so I would need to go through the list of images and remove the db record that matches the name (or find it and update its URL). I could do this (at most, there would be two refs with the old token that I would need to replace), but then I saw people doing it via option 2, though not necessarily with my exact situation.
The last thing I did see a few times, were similar questions with generic responses pointing to Cloud Functions, which I will look into right after posting, but I wasn't sure if that was overcomplicating things in my case, so I figured it couldn't hurt too much to ask. I initially saw/read about Cloud Functions and the fact that Firebase's db is "live," but wasn't sure if that played well in a React/Redux environment. Regardless, I'd appreciate any insight, and thank you.
In researching Cloud Functions, I realized that the use of Cloud Functions wasn't an entirely separate option, but rather a way to accomplish the first option I listed above (and probably the second as well). I really tried to make this clear, but I'm pretty confident I failed... so my apologies. Here's my (2-Part) working solution to syncing references in Firebase DB to Firebase Storage urls (in a React Redux Web App, though I think Part One should be applicable regardless):
PART ONE
Follow along here https://firebase.google.com/docs/functions/get-started to get cloud functions enabled.
The part of my database with the info I was storing relating to the images was at /projects/detail/{projectKey}/imgs and had this structure:
{
<autoGenKey1>: {
name: 'image1.jpg',
url: <longURLWithToken>
},
<moreAutoGenKeys>: {
...
}, ...}
My cloud function looked like this:
exports.updateURLToken = functions.database.ref(`/projects/detail/{projectKey}/imgs`)
.onWrite(event => {
const projectKey = event.params.projectKey
const newObjectSet = event.data.val()
const newKeys = Object.keys(newObjectSet)
const oldObjectSet = event.data.previous.val()
const oldKeys = Object.keys(oldObjectSet)
let newObjectKey = null
// If something was removed, none of this is necessary - return
if (oldKeys.length > newKeys.length) {
return null
}
for (let i = 0; i < newKeys.length; ++i) {// Looking for the new object -> will be missing in oldObjectSet
const key = newKeys[i]
if (oldKeys.indexOf(key) === -1) {// Found new object
newObjectKey = key
break
}
}
if (newObjectKey !== null) {// Checking if new object overwrote an existing object (same name)
const newObject = newObjectSet[newObjectKey]
let duplicateKey = null
for (let i = 0; i < oldKeys.length; ++i) {
const oldObject = oldObjectSet[oldKeys[i]]
if (newObject.name === oldObject.name) {// Duplicate found
duplicateKey = oldKeys[i]
break
}
}
if (duplicateKey !== null) {// Remove duplicate
return event.data.ref.child(duplicateKey).remove((error) => error ? 'Error removing duplicate project detail image' : true)
}
}
return null
})
After loading this function, it would run every time anything changed at that location (projects/detail/{projectKey}/imgs). So I uploaded the images, added a new object to my db with the name and url, then this would find the new object that was created, and if it had a duplicate name, that old object with the same name was removed from the db.
PART TWO
So now my database had the correct info, but unless I refreshed the page after every time images were uploaded, adding the new object to my database resulted (locally) in me having all the duplicate refs still, and this is where the realtime database came in to play.
Inside my container, I have:
function mapDispatchToProps (dispatch) {
syncProjectDetailImages(dispatch) // the relavant line -> imported from api.js
return bindActionCreators({
...projectsContentActionCreators,
...themeActionCreators,
...userActionCreators,
}, dispatch)
}
Then my api.js holds that syncProjectDetailImages function:
const SAVING_PROJECT_SUCCESS = 'SAVING_PROJECT_SUCCESS'
export function syncProjectDetailImages (dispatch) {
ref.child(`projects/detail`).on('child_changed', (snapshot) => {
dispatch(projectDetailImagesUpdated(snapshot.key, snapshot.val()))
})
}
function projectDetailImagesUpdated (key, updatedProject) {
return {
type: SAVING_PROJECT_SUCCESS,
group: 'detail',
key,
updatedProject
}
}
And finally, dispatch is figured out in my modules folder (I used the same function I would when saving any part of an updated project with redux - no new code was necessary)

Filter cached REST-Data vs multiple REST-calls

I'm building an Angular Shop-Frontend which consumes a REST-API with Restangular.
To get the articles from the API, I use Restangular.all("articles") and I setup Restangular to cache this request.
When I want to get one article from the API, for example on the article-detail page by it's linkname and later somewhere else (on the cart-summary) by it's id, I would need 3 REST-calls:
/api/articles
/api/articles?linkname=some_article
/api/articles/5
But actually, the data from the two later calls is already available from the cached first call.
So instead I thought about using the cached articles and filter them to save the additional REST-calls.
I built these functions into my ArticleService and it works as expected:
function getOne(articleId) {
var article = $q.defer();
restangular.all("articles").getList().then(function(articles) {
var filtered = $filter('filter')(wines, {id: articleId}, true);
article.resolve((filtered.length == 1) ? filtered[0] : null);
});
return article.promise;
}
function getOneByLinkname(linkname) {
var article = $q.defer();
restangular.all("articles").getList().then(function(articles) {
var filtered = $filter('filter')(articles, {linkname: linkname}, true);
article.resolve((filtered.length == 1) ? filtered[0] : null);
});
return article.promise;
}
My questions concerning this approach:
Are there any downsides I don't see right now? What would be the correct way to go? Is my approach legitimate, to have as little REST-calls as possible?
Thanks for your help.
Are there any downsides I don't see right now?
Depends on how the functionality of your application. If it requires real time data, then having REST calls performed to obtain the latest data would be a requirement.
What would be the correct way to go? Is my approach legitimate, to have as little REST-calls as possible?
Depends still. If you want, you can explore push data notifications, such that when your data from the server is changed or modified, you could push those info to your client. That way, the REST operations happens based on conditions you would have defined.

Linking Data in Firebase

I am designing a forum and have a layout like this in on my Firebase:
root
|-posts
|-postID1
|-creator: "userOne"
|-creatorUID: "simplelogin:1"
|-text: "Some Text"
|-postID2
|-creator: "userTwo"
|-creatorUID: "simplelogin:2"
|-text: "Some Other Text"
|-profile
|-simplelogin:1
|-firstName: "John"
|-user: "userOne"
|-simplelogin:2
|-firstName: "Sue"
|-user: "userTwo"
On my forum page. I simply use a Angular ng-repeat to get all of the posts on Firebase and list them out. I also want to print out the first name of whoever created the post, but right now, I can only access {{ post.creator }}, which just gives the username of the person who posted. How can I link the post's creator (or creatorUID) with the first name field of that person's profile?
If you're just displaying the the users firstName I would place the users name in the postIDX object.
This would be quicker and produce less requests to Firebase with you going back and fourth with each post to get the usersFirst name.
more information on structuring data and best practices can be found here: https://www.firebase.com/docs/web/guide/structuring-data.html
Updated from response
if you wanted to get the user details then within every request to the postIDx you'd need to do something similar to this (not tested and quick mock up).
var fbRef = new Firebase('firebase path'),
postDetailsObject = {};
fbRef.child('posts').once('value', function(snapshot) {
// loop through each post
snapshot.forEach(function(childSnapshot){
var postDetails = childSnapshot.val(),
profileDetails;
postDetailsObject.post = postDetails;
fbRef.child('profile/' + postDetails.creatorUID).once('value', function(profileData) {
postDetailsObject.profile = profileData;
});
})
});
Then return the postDetailsObject in to angular so you can loop through the single object.

I can't seem to find a way to fetch a specific record from Firebase

This is a simple service I've built for Firebase for an application. I've had to jury-rig some elements and I've made absolutely sure I am using the latest versions of firebase and angular fire since it seems to be changing pretty fast. These first few lines are pretty straightforward,
app.factory('Ship', function ($routeParams, $firebase, FIREBASE_URL) {
var ref = new Firebase(FIREBASE_URL + 'ships');
The problems begin here. Depending on what I intend to do with the firebase object, at times it needs to be $asObject, at other times not. It depends on the tutorial and the most recent ones would seem to indicate that
var shipsObj = $firebase(ref).$asObject(); // Is this necessary
var ships = $firebase(ref); // in the most modern version?
var Ship = {
all: shipsObj, // This works fine
create: function (ship) {
return shipsObj.$add(ship); // This also works fine
},
find: function (shipId) {
console.log($routeParams.shipId); // <--this ID appears as the correct numerical ID
Then, there is the next six lines, NONE of which work. They all produce an error indicating that they are undefined.
console.log(shipsObj.$child(shipId));
console.log(ships.$child(shipId));
console.log(shipsObj.$getRecord(shipId));
console.log(ships.$getRecord(shipId));
console.log(ships.$keyAt(shipId));
console.log(shipsObj.$keyAt(shipId));
},
I won't bore you with repeating the next method multiple times as well, but $remove isn't working either.
delete: function (shipId) {
return ships.$remove(shipId);
}
};
return Ship;
});
Assuming your using v0.8 of AngularFire you'll want to use $asObject() or $asArray() to get at the actual data. Here's the official blog post that discusses the changes in v0.8: https://www.firebase.com/blog/2014-07-30-introducing-angularfire-08.html
So to access a ship by its id you could do:
var shipsObj = $firebase(ref).$asObject();
console.log(shipsObj[shipId]);
You may also want to take a look at the API docs for AngularFire: https://www.firebase.com/docs/web/bindings/angular/api.html
A lot changed in v0.8 and it just came out (July 2014) so if you're basing your code on anything older than that then it probably won't work

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