I am developing a desktop program, a website and an application and they both communicate through the same database. I started researching about making these apps real-time, that I don't need to update to receive a new registration or a change to something. I discovered websockets and socket.io, saw some examples and read a lot about it, but then I saw that there are some databases that already do this and one of the most famous is firebase. What I would like to ask here is, using firebase can I make an application in real time? An application that when registering data to the database, all other connected applications receive this data in real time?
In google firebase, you can create listeners on the client-side to respond to any changes in the backend. Check out https://firebase.google.com/docs/firestore/query-data/listen.
This is great if you need to store data, but if you are purely looking to send information between clients and there is no need for any persistence, I would recommend using WebSockets.
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We are researching at using Expo to build an offline first app that requires medium storage and encryption.
It is an app comprising of several user filled forms and data tables.
The core requirements are:
Offline ability. Allowing the user to fill in several forms whilst offline and have the device push this data via POST requests when the device receives a connection.
So far we have a basic working offline app that utilises redux offline (https://github.com/redux-offline/redux-offline) to store client actions when the device is offline and automatically sync this when the device receives a connection.
Store a medium amount of JSON data (100MB+) for offline usage. The app needs to grab this data from a GET request and store it locally. The JSON data is used as part of the form journeys, allowing the user to select from predefined dropdown fields, etc.
We are unsure how to approach this with Expo.
All the stored data must be encrypted.
We are unsure how to approach this with Expo.
Authentication via Keycloak.
This is proving difficult due to the lack of documentation on Expo. It seems it should be done via AuthSession (https://docs.expo.dev/versions/latest/sdk/auth-session/).
The storage and encryption requirements are proving particularly difficult to work around. Are these possible with Expo? Or would we need to eject for React Native for these? Any advice would be much appreciated. Thanks
A few years ago I was instructed to build an Windows Desktop application to control several devices, add and check data from a local database among other stuff. At the time the answer was very simple and I decided to create a WinForms application that provided a solution to the request, the app would control the devices, it would store data in a local database and it would show the data in it's UI.
Even though it worked perfectly for a while, the project has now expanded a lot, to the point were it consists in several projects including two REST API services working on different servers as windows services, a Xamarin Android and iOS apps that access those servers and some other stuffs. Obviously, my dicision of not separating the original Winforms server application's UI from the server stuffs has kick me in the rear. Another problem is that the solution has been working for a long time and the client does not want to give me much time for updating (which by the way it would probably require to rethink everything) so he want me to give him a fast and simple solution to the problematic server - client scheme.
So again I decided to try a fast solution (probably not the right one, but its a matter of time) and created a Blazor app that connects to the local database and it would work in the same server where the winforms app is, guaranteeing that none one will touch that app.
The problem now is that I need a way to show real time notifications in the blazor web UI and update its datagrids, etc., when the winforms app receive an event from one of the devices. At first I thought of SignalR, being the blazor app the server for SignalR and the winforms just a client, but I have no experience with it. Although if SignalR is the answer I'll deal with it.
So, the question is: which is the best way to send real-time event notifications from a winforms application to a blazor app?
Thanks in advance
I would like to ask how to create an ionic app that talks to Laravel API but still works offline when there's no connection.
Let's say i have to write a quiz mobile app in Ionic and it requests for Laravel API to retrieve the questions as well as store the scores in db.
I'm just starting to learn Ionic and i'm really confused right now on how to approach this.
What confuses me most are:
Does the Ionic source live inside the Laravel source code w/c serves the API?
If i want the Ionic app to be installable, should the Laravel source code be included as well during the compilation process?
Thanks in advance for any help.
Your php or in general server side code is completely independent from your ionic application. If you want your app to work offline you should think about something like fetching a high number of information initially and work with this data without making any additional requests.
However your ionic app does only contain the frontend. You could implement some logic for local storage, but if you want to keep information hidden from the user (e.g. solutions) you have to put that logic on a dedicated server.
In the few details you provided, I can say the Laravel code does not live inside the ionic app. The ionic app is separate from the backend API by Laravel. You are possibly trying for a ReST based architecture where you communicate with your Laravel Server with an API. You need to keep those codes separate.
However without any internet, you won't be able to access those APIs, so you will just be able to show some static data, or you could serve from a DB and show later. For how to use the sqlite db you can look here
In your backend you can have an API like
http://example.com/api/v1/questions/1/
Which will fetch a question with options and if you want the app to have the answer for offline storage you may have that as well. When a user answers, you may check whether you have internet access and send answer and verify if you do, else you may save the answer in your DB and sync when you do have access. You can fetch multiple questions so that a user may answer multiple questions in case he/she will not have internet access.
Hope it helps. :)
I am creating an app that involves sending and receiving settings... The desktop application is constantly sending information to a hosted MySQL database, and the Android app will query this same information. It is something similar to the whatsapp web (but in this case, I'll be using a desktop app instead of webpages).
Until this part, everything is working as I need... but, this same Android app will be used to send settings to the desktop app, and the desktop will read and change its settings according to what was just sent.
If I need to constantly query the hosted MySQL database and check if there is any kind of changes sent from the Android, I believe that I'll have a performance drop... each time a query loop is finished, I would have to query, check for any modifications and so on.
Is there a better or correct way to do this kind integration between two apps? I've read something about WebSockets, but I don't have much technical information about this, neither examples that I can use in this case.
Thank you very much for your knowledge sharing.
Here are some useful sites on WebSocket:
http://websocket.org
http://blog.kaazing.com/ [some useful blog posts]
http://www.html5rocks.com/en/tutorials/websockets/basics/
https://goo.gl/5OaJff [mozilla site]
You may want to consider the Observer/Observables pattern. The MYSQL is the Observable and your desktop app and Android app are Observers (and you can add other Observers in the future). Its a common pattern with lots of examples out there. But you'll need a centralized WebSocket server and an Observer/Observable coordination subsystem. You can setup a pub/sub message broker that uses WebSocket with a nice JMS, MQTT, etc, API to make your life easier. ActiveMQ, IBM MQ Lite, Kaazing JMS Edition... lots of options.
full disclosure. I work for Kaazing.
I am trying to develop a web application that can communicate with another web application. App1 is an app developed using Angular.js and Struts2. This apps sole purpose is to perform search queries on several databases and returning the information about the products for the user to view. App2, the current app I am developing, will be developed using Angular.js and Flask/Python. This app will be responsible for storing the products the user selects in a shopping cart and allowing the user to make a purchase.
I am stuck as to how to get the two applications to communicate(passing login information, selected items ids, etc.) with eachother.
I have tried passing information via a url redirect (http://www.example.com/?myVar=someData&...) but Angular is giving me a lot of trouble to try and get around that. Even if I can get this to work, I think it would be insecure as data the user shouldn't know will be exposed in the url.
My second thought would be to somehow access the session data from App1 in App2 but that could also lead to security issues.
My final thought would be to some how make a call to App1 that returns a json object that can be parsed in App2 but I am not entirely sure how to pass that information along.
How can I get the two applications to communicate with each other?
Thanks for your help
In my opinion this isn't really within the scope of AngularJS. However, I believe that the best, most accepted practice for communication between web applications in this day and age is RESTful Web Services.
It's not a small topic, but once you get the concept behind it you can use it in any programming language that supports web applications (Java which I'm assuming you're using because of struts has multiple REST libraries, I prefer Jersey but that's just me).
It's also an amazing way to use your Angular front end to talk with its own back end. The entire Angular $resource framework is built around the idea of using RESTful services.
Check out this link on Wikipedia for a brief synopsis of what makes a service RESTful: http://en.wikipedia.org/wiki/Representational_state_transfer#Applied_to_web_services
Now, that applies to most of what you asked. As far as login information is concerned, that's going to depend on your security implementation. A lot of times you can put information like that in the header of a web services request, and only accept requests that come from trusted servers, etc. but there's a good bit of stuff to understand there. It's an entirely separate topic.
Hopefully this helps you get started. Let me know if you'd like more information or pointers.