Client Side Transactions in Azure App Service Offline Sync - xamarin

Is it possible to leverage transaction on the client, when using azure app service offline sync?
It seems to me that you can pretty much only insert into the SQLite store a record at a time, but ideally i'd like to be able to commit multiple records in a transaction.
I'm using Xamarin with Android right now,but will be also supporting iOS.
Thanks
Matt

Unfortunately, on Windows, Xamarin, and Android you can only commit one record at a time on the local MobileServicesSQLiteStore. This is because changes need to be made one at a time using methods like SyncTable.UpdateAsync, which is how you mark a change as being tracked to send to the server.
On native iOS, the Mobile Services offline sync feature uses Core Data, which does support a form of transaction (https://developer.apple.com/library/ios/documentation/Cocoa/Conceptual/CoreData/Articles/cdMemory.html). If you use these APIs, you still need to make calls to the Mobile Services SDK methods to track each individual change in the internal tracking tables.
Why do you need transactions on the client side? There might be a different way to achieve your goal.

Related

Send Push Notification In Xamarin Forms Without Firebase

I am working in banking sector and we have different portals for managing employee information, performance etc. I want to send push notification in mobile app from our asp.net web service when a new event (e.g. a Line Manager has to approve any pending request) occurs. How can I send notification to mobile app from our servers(where the web service has been deployed)? We don't have rights to place employee data on cloud servers or cloud databases.
Hopefully this is your request:
We don't have rights to place employee data on cloud servers or cloud
databases.
And not this:
Send Push Notification In Xamarin Forms Without Firebase
As they are entirely different. If you want to send data to Android devices you need to use Firebase for that just like you need to use Apple's servers for iOS devices. However you don't need to have any database or store data on them.
You can use PushSharp nuget if you want to minimize 3rd party server usage or some other similar solution.
Just for the record using Firebase (or other services like Azure) to send push notifications doesn't require you to place employee data on cloud servers either. Firebase and other solutions contain range of services that can be used independently and it seems that you consider them as all or nothing solution.

Intercepting PouchDB communications with CouchDB backend

I am considering PouchDB & CouchDb as an alternative to Amazon Cognito Sync for a hybrid mobile app that will need data synced between devices and users. I have pouchdb working in a small sample app that syncs with a local couchdb.
I need to be able to intercept the communications back and forth between the pouchdb and couchdb in Java in order to do things in response to these sync events. Sort of like Amazon Cognito Sync's sync triggers. Also, I keep thinking much like Spring's AOP around.
Since the couchdb has a rest interface, I thought I could point the pouchdb to my application server which has a controller listening for any request with the db name as the base. When a request, from pouchdb comes in the Java Rest Controller can optionally do something, then forward the request to the real rest endpoint of the couchdb and get a response, then optionally do something again, then return the response to the pouchdb.
Does this seem like a feasible solution? I am currently working on trying to get this concept working. Has anyone else done anything like this? Any major pitfalls to this approach? Currently, I'm using Java 8 with Spring Boot & Jersey.
I think the architecture goes like this:
Data is empty everywhere.
Data changes, the device where the data changed pushes via a REST APIs.
Your server "master", send notification GCM or APN to devices.
In your notification listener, you check the type of notification and you sync the data.
If a new device connects to your "list of devices to sync" you send a push notification to sync the data.
Keep a list of connected devices.
The same ideas goes for every device/web browser. You have a local cache that you push to the "master" if it changes locally.
You will have many cases to deal with, and I don't think there are open source projects that offers the same patter as Cognito Sync.
Also think about scalability, devices don't have to pull your "master", the master sends notification to trigger devices to download the data.
You have to deal with diffs, regular checks, and so on ...
Good luck

How to move Parse.com database to my own server and still use Parse.com SDK?

I'm using Parse.com SDK services for my Android app.
I've seen that Parse had released their Android SDK as an open source project on Github on this address.
My app is almost finished, and when I'm uploading it to the Play Store, I don't want to be controlled by Parse.com (I mean that I don't want to be blocked someday, or I don't know that), so I want to move my whole database to my own server that hosted on a secure company.
I've checked the open source project on Github and realized that all I need to use it on my own server is to generate an Application ID and a client key.
So I want to ask if someone knows how to generate an Application ID and a client key of Parse to use it on my own server, or that you maybe knows another way of moving it to my server? And one more question: Today I'm using also Facebook SDK with my app. If I will move my database to my own server, will I still be able to use Facebook SDK on my app?
Thanks!
I have write an article about how to migrate parse to a custom server.
https://medium.com/#jcminarro/run-parse-server-on-your-own-server-using-digitalocean-b2a7d66e1205
There's a massive difference between Parse open-sourcing their SDKs compared to revealing their entire backend architecture and its configuration.
The open-sourced SDKs are essentially wrappers for Parse's REST API along with some convenience functions and logic for natively interpreting the JSON data Parse is transmitting.
At a high level, Parse uses MongoDB for its core database and is entirely hosted using AWS (Amazon Web Services). The entire architecture is highly complex and is not something you could just drag and drop onto your own software stack or hardware backend.
To help give you a better idea of how Parse achieves all of their services, here's an interesting presentation their Dev Ops team gave at an AWS convention. Suffice it to say, hosting the backend services for over 180,000 apps requires a complex infrastructure and that is the "secret sauce" so to speak for Parse and is why Facebook purchased them for over $85 million two years ago.

MS Sync Toolkit how to handle huge initial download

We're using Microsoft Sync Framework Toolkit to allow some iOS devices to synchronize their SQLite local storage with a central SQL Server database over an OData service (just like the sample does).
The problem is that the central database is quite big (more than 500 MB) and that the customer want to initially replicate all his content on their devices.
So we configured the service to sync all tables but it crashes the first time a device tries to sync (OutOfMemoryException).
How should we design/configure the service to manage such a situation? Setting filters doesn't seem to fit our needs since we need all the data.
I should add that we tried to configure SetDownloadBatchSize with no luck. Maybe there is something to configure on the client as well?

What is the best solution for real-time bi-directional communication between a web application running on a mobile phone and a server?

I'm looking at having thousands of simultaneous connections from mobile phones to the server whereby anytime a user interacts with his cell phone, the data is sent and logged by the server. Also, anytime the server has new information for that user, the server can push that information without a browser refresh. I am wondering what is more stable and how you would build this?
A good real-time framework or infrastructure will have numerous APIs that should let you connect any device, no matter the technology, to the real-time server e.g. an iOS client library for iPhone and iPad, a JavaScript client library for numerous platforms including normal and mobile web, an Android compatible Java library and so on.
An interesting idea might be to choose which ever framework or real-time service suits your needs best and then using something like PhoneGap. But, as #rt2088 says, it depends if you need the notification app to be running as a service on the phone or as a standalone application.
The choice will also depend on whether you want to install, host, maintain and manage the scaling of your own real-time services or not. If not, there are a number of services out there who you could use so you can concentrate on building your application. If you do want to manage your own infrastructure then the Comet Maturity guide could be a good start. It's a little out of date but is still probably the best reference available.
the ability to push new content the
user based on his GPS location which
is "pinged" to our server. Based on
that, we deliver local content. What
frameworks are you talking about?
There are a number of real-time frameworks available at the moment. Some are hosted services and others require installation on your own hardware. The majority of them will come with a bunch of libraries in different technologies that make it easier to get up and running with them e.g. a JavaScript library that wraps the WebSocket object and also manages fallback for web browsers that don't support WebSockets.
I've just created a Real-Time Technologies Guide in which I've listed all the real-time technologies that I could think of and provided a bunch of tags associated with each.
wouldn't a javascript client library
cover all platforms if it is a web
appilcation?
If the application is a web application then yes, a JavaScript library would be all you need for the client application. The server side libraries that you require would depend on the real-time technology you choose.
Best solution to achieve this is to use the WebSocket communication. It is bidirectional asynchronous communication. Currently every browser supports this new standard and plenty of code snippets available. You just have to google it. There are many server and client side frameworks. choose the one best suits to your requirement.
The details of the WebSocket specification is available at -
Websocket specification
Do you need notification when user uses mobile browser of handset or the mobile handset itself (performing non-browser tasks)? Based on that, the framework to record user activity can be selected.

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