I've been working with Firebase for 1 month, and now I'm starting to understand how it works.
In my App I've got some supermarket products like fruit, vegetable or others.
In real life I've got some NFC tags applied on the products.
In the database, there is a node which contains products, one node which contains NFC Ids, and one node which contains relations between them.
The Product's keys are pushed Ids while the NFC's are their Ids.
With my phone and the embedded NFC reader I can read the tags and tell the system which product I'm scanning.
Now I'd like to create a record each time a phone reads a NFC.
On the record, I'd like to put the data about the phone, the NFC Id's and the Product Push Id.
Is there a Server Side way, maybe with rules, to query the relation between NFC and Products and put it on my new record, the Product Id instead of the relation Id?
In this way I'll cut a lot of Client Side code which is making may app too complicated.
Thanks.
I have also faced this problem. However, Firebase has introduce Cloud Function a month ago. Try to check the official link out. It allow you to put some logics in server side.
https://firebase.google.com/docs/functions/
I myself haven't done much research on this feature but instead of thinking about the communication as Request and Response you need to see it as Database trigger event.
Is this what you looking for ?
Related
I was reading this article about NFC and Kotlin and tried to implement the Code in my App. I want to send a string from one device (from the customer) to the receiving device (supplier) for a faster checking - in (for example if you have booked a table, the device reads the booking-id from the customer-app and displays the regarding information on the supplier-device.
The problem is that:
this.nfcAdapter?.setOnNdefPushCompleteCallback(outcomingNfcCallback, this)
this.nfcAdapter?.setNdefPushMessageCallback(outcomingNfcCallback, this)
both Callbacks from the NFC Adapter are deprecated since API 29.
So is there any other way left to do this?
Google's documentation mentions the following concerning the deprecation:
File sharing can work using other technology like Bluetooth.
Indicating the feature was originally intended for file sharing,
not the sending of short strings.
Two solutions come to mind:
On the customer's device you generate a QR code containing the string you want to send over. With the supplier's device you scan the QR code. This way is often used for mobile payment and customer reward/discount apps.
A web service where the customer sends over their ID and then information is returned from a database.
You can also combine these approaches by for example letting the customer scan a static printed QR code containing the supplier ID. With the supplier ID your app could then submit the customer's booking ID and the supplier ID to your web service after which booking info is returned.
For this question, I am not looking for specific answers, or code or anything, but moreso suggestions on what techniques to employ to accomplish my goal.
I am very new to Android development. I have a bit of a background in Java.
The App I'm looking to build would have two types of users. The Narrator and the Participant.
The Participants would fill out a few fields, and click a button. This data would be integer and string values. Nothing terribly complex. The participants don't really need any sort of feedback beyond success or failure.
The Narrator's app would receive this information, and build a list displaying the information the Participants sent. Possibly the Narrator is able to send a message to the Participant devices prompting them to fill out and send their inputs, but not necessary.
What I am looking for is direction on which sorts of methods or techniques to accomplish this. It could be accomplished over Bluetooth, but even accomplishing it over the internet is arguably better.
It would need to be able to generate a unique session that users can locate and "connect to", as well.
If there are other questions that have info that would help me, feel free to link them. I assume there are. The rub is that I wasn't exactly sure how to ask this question with enough brevity to yield useful search results.
Thanks very much.
Look at realtime cloud db solutions to create the realtime, connect to session that you want to create.
In your app create a registration activity where the user can register as a participant or narrator. Store the user details on the cloud once register with a usertype key under your user model/map.
For example to define a value to usertype use like this.
usertype = 0 for participant
usertype = 1 for narrator
For your main activity you can create 2 layouts:
Layout1 (participant)
Layout2(narrator)
When user login you read the usertype value and assign layout in the oncreate method.
Example
if(usertype==0){
setContentView(Layout1)}
Within the layouts you will add your edittexts, views and buttons as per required for narrators and participants.
You will also write your functions for narrator in its own class/void and the same for participant.
Then use the usertype value to access the defined classes/voids.
You can have a look at firebase as a realtime database or there are plenty other options.
Happy coding.
So according to your explanation, participants will send something to other users which are Narrator. So something like chat system. In that case, you can use Firebase Realtime database. First, see how Firebase real-time database works. You can check this to get an idea.
So when participants fill up something it must receive by the narrator. When participants submit something you just need to send a push notification to all participants. So when participants click on the notifications you will redirect him to a specific activity and can load the participant's submitted form in that.
I recently started to learn Android and I came across a problem. I want to create a code for Firebase (the database I am using to store values) such that the contents from one set are matched to elements in another set.
The scenario is as follows: there is a student who wants to learn or is interested in learning a new skill (C/C++, drawing, music, etc.), if he were to update them in their profile, he should get suggestions as names of other users registered in the application who have already listed their skill set.
It is much like how Facebook suggests common friends, but here, the basis for suggestion is what skills the user has and what he wants to learn.
I worked on the same thing for one of my apps. I'll write about what I did to achieve that
First of all, you need to design your Realtime Database structure in a way to achieve that.
Example of a Individual User node in your database at firebase could be like
User
- Personal Details
- First name
- last name
- Dob
- Interests (values like "music,movies,sports") //Separated by a comma
- ...
Now lets say User A likes "music" and that you need to suggest him other users who likes music too, In this case what you can do is retrieve all the users who have interests "music" in their profile.
reference.addChildEventListener()
In here,inside the onChildAdded() you can compare to see if the Interest of a particular user has music in it. (if it does, add that user to your arraylist for your recyclerview to display it.)
Hope it helps!
I am currently using api.ai , to create agent to perform specific tasks, but one question i don't have answer to is , can i make it learn something while chatting , mean that i speak my name is 'John Cena' and she should store it and then whenever i ask her again bot should answer me that. i know there is a way to do it by logging into api.ai web and manually add entries , but it will not help, is there any work around programmatically or automatically ? the file i've been using to practice is given in github . and here is working DEMO
You basically need for your bot to "learn" facts. There are many different ways to achieve this, but recently the most common way is to arrange knowledge into Semantic "Triples" and store the knowledge into a Graph repository (like Neo4j, Titan, Spark Graph, etc). In your example, "my name is John Cena" would translate into a Triple like ("anubava","Name","John Cena"). That way, the next time you are logged in as anubhava and ask "What is my name?", it would translate into a Graph search that will return "John Cena". A word of caution, achieving this is not trivial and would require some significant amount of fine tuning. For more info, you can check here and here.
Finally, most complete solutions (that I know of), are Server Side solutions. If you want for the whole knowledge base to reside in your mobile device, you could probably use the resources there as inspiration, and build your own Linked Data repository using an embedded database.
Hope this helps. Good luck.
To store and recall the user's name, you'll need to set up a webhook with some basic data persistence capabilities. Any database or key-value store would work fine.
Here's the breakdown:
Implement webhook fulfillment for the intent that captures the user's name. The webhook should store the name along with a unique, identifying ID that you should supply from your front-end in either the sessionId or as a context parameter in your call to /query.
Implement webhook fulfillment for the intent that reads the user's name. The webhook should look up the name by ID and return a response that tells the user their name.
The high-level docs for writing a fulfillment webhook are here:
https://docs.api.ai/docs/webhook
We are building an android app that needs to synchronize phone contacts with people already registered on the app. We are using firebase
To do this, we'd like to retrieve a list of existing users based on their phone numbers.
I have managed to retrieve users based on their phone number with ref.orderByChild("phone").equalTo($phoneNumber)
But I am wondering if there is a way of passing a list of phone numbers, instead of querying for each phone number one at a time ?
Something like this:
ref.orderByChild("phone").isIn([phone1, phone2, phone3])
I am just beginning to learn Firebase but I love the concept :)
Thanks a lot for your answers!
Firebase doesn't have or or in operators on its queries.
The closest you can come with with the startAt and endAt functions, to select a range. But that doesn't work for your use-case.
Normally when people are asking for this type of operation, there is a relation between all the pieces that they're trying to combine in a query. For example in your case, the use-case is likely something like: "get the name for all contacts in the user's address book".
In such a situation there are a few options:
monitor each contact with a separate query
embed the necessary metadata for each contact into the user's address book
Option 2 is the cheapest way to get the information, because you only need to read the address book. But it comes at the cost of data duplication, which more relationally trained developers are unused to. See this answer for a coughgreatcough example of such denormalization: Firebase data structure and url
Option 1 is not nearly as expensive as you may expect, since Firebase will open a socket connection only once and then perform all additional queries over that same connection.