first tweet in the morning
Lets check Jerome
https://www.youtube.com/results?search_query=ML.NET
Downloaded the visual studio extension
https://dotnet.microsoft.com/apps/machinelearning-ai/ml-dotnet/model-builder?WT.mc_id=ondotnet-c9-cxa
Sometimes you want to send a zip with your visual studio solution or project, but after you archive your files you realize that the file size is huge, well worry no more you can use the following script (a .bat file) to clear all the temporary files in your visual studio solution
just save the following code in a ms-dos bat file, name the file ClearTeam.bat
rem start of the script @echo off for /d /r . %%d in (bin,obj,packages) do @if exist "%%d" rd /s/q "%%d" FOR /R %%H IN (*.log) DO del "%%H" FOR /r %%G IN (*.bak) DO del "%%G" FOR /R %%J IN (*.suo) DO del "%%J" IF EXIST .vs rd .vs /s/q rem end of the script
to run it, just double click in the bat file or execute it but call the file name in console, in this case, ClearTeam.bat
I have been using XPO from DevExpress since day one. For me is the best O.R.M in the dot net world, so when I got the news that XPO was going to be free of charge I was really happy because that means I can use it in every project without adding cost for my customers.
Nowadays all my customer needs some type of mobile development, so I have decided to master the combination of XPO and Xamarin
Now there is a problem when using XPO and Xamarin and that is the network topology, database connections are no designed for WAN networks.
Let’s take MS SQL server as an example, here are the supported communication protocols
To quote what Microsoft web site said about using the protocols above in a WAN network
Named Pipes vs. TCP/IP Sockets
In a fast-local area network (LAN) environment, Transmission Control Protocol/Internet Protocol (TCP/IP) Sockets and Named Pipes clients are comparable with regard to performance. However, the performance difference between the TCP/IP Sockets and Named Pipes clients becomes apparent with slower networks, such as across wide area networks (WANs) or dial-up networks. This is because of the different ways the interprocess communication (IPC) mechanisms communicate between peers.”
So, what other options do we have? Well if you are using the full DotNet framework you can use WCF.
So, it looks like WCF is the solution here since is mature and robust communication framework but there is a problem, the implementation of WCF for mono touch (Xamarin iOS) and mono droid (Xamarin Android)
You can read about Xamarin limitations in the following links
Android: https://docs.microsoft.com/en-us/xamarin/android/internals/limitations
iOS: https://docs.microsoft.com/en-us/xamarin/ios/internals/limitations
I don’t want to go into details about how the limitation of each platform affects XPO and WCF but basically the main limitation is the ability to use reflection and emit new code which is needed to generate the WCF client, also in WCF there are problems in the serialization behaviors.
Well now that we know the problem is time to talk about the solution. As you know XPO has a layered architecture ( you can read about that here https://www.jocheojeda.com/2018/10/01/xpo-post-5-layered-architecture/)
So basically, what we need to do is to replace the WCF layer with some other technology to communicate to the database server
The technology I’ve selected for this AspNetCore which I would say is a really nice technology that is modern, multi-platform and easy to use. Here below you can see what is the architecture of the solution
AspNetCore
Rest API
So, what we need basically is to be able to communicate the data layer with the data store through a network architecture.
The network architecture that I have chosen is a rest API which is one of the strong fronts of AspNetCore. The rest API will work as the server that forward the communication from XPO to the Database and vice versa, you can find a project template of the server implementation here https://www.jocheojeda.com/download/560/ this implementation references one nuget where I have written the communication code, you can fine the nuget here https://nuget.bitframeworks.com/feeds/main/BIT.Xpo.AgnosticDataStore.Server/19.1.5.1
Also we need a client that is able to interpret the information from the rest API and feed XPO, for that I have created a special client you can find here https://nuget.bitframeworks.com/feeds/main/BIT.Xpo.AgnosticDataStore.Client/19.1.5.1
The client implementation has been tested in the following platforms
The client implementation has been tested in the following operative systems
In this link, you can see a full implementation of the server and the clients (XAF and Xamarin)
What is next? Well here are a few topics for the upcoming posts
If you updated your visual studio to version 16.2.0 and you are using MSBuildSdkExtras your project won’t compile.
so to fix this problem (this is a temporary fix). You need to add the following lines to your csproj
<PropertyGroup Label="Android DesignTimeBuild error workaround"> <DesignTimeBuild>false</DesignTimeBuild> </PropertyGroup>
There are times when you have been working on your new exciting project and it looks so good that you just want to release it as soon as possible so the world can be blessed with your new NuGet package but wait your new library is a complex library and require special setup instructions after it has been installed.
Well, we can solve that problem by adding a readme file with all the setup instructions, to do that add the following XML snippet to your csproj file, then you can just add a ReadMe.txt to your project. Now when the end-user install your NuGet package the read me file will automatically open
<ItemGroup> <None Include="ReadMe.txt" pack="true" PackagePath="." /> </ItemGroup>