How to Structure Projects for Multiple Xamarin Apps - visual-studio

My team is working on translating several legacy mobile applications to Xamarin Forms apps. Currently each application is in its own solution, which is not ideal when it comes to the fact that they all use a common set of backend software libraries. We were planning to consolidate all the smaller solutions into a single solution, containing the apps as well as the common libraries.
However, one of my teammates brought up a valid concern about how with a single Xamarin Forms app, several projects could get generated (core, Android, iOS, etc.), with the eventual result of a generally unwieldy solution. I agree with him that the current setup probably would not scale too well as we add more apps -- even if we group projects in solution folders, Visual Studio will eventually slow to a crawl after a certain amount of projects exist in the solution.
So we are considering just going back to having each app in its own solution, each solution containing the few Xamarin Forms projects for that app, as mentioned above. But this brings us back to the question of how to reasonably manage the shared library code. My current thought would be to just use shared project(s) for the libraries, or maybe assemble them into NuGet package(s) the app solutions would consume. Am I on the right track here, or does anyone know of a better way to do this?

There are several different ways to manage a shared code project using subtrees, submodules, NuGet packages, etc. There are pros and cons to each so it's best to decide based on the expected use case for that project.
Subtrees essentially take a copy of the remote repo and pull it into the parent repo. This makes it easy to pull in changes from the remote repo but if changes are expected to be pushed back it can be significantly more difficult since it has no knowledge of the remote repo. While it is possible to push changes back it can take a significant among of time to do depending on the amount of history of the repos.
Submodules are similar to subtrees except that instead of taking a copy it tracks the remote repo based on a specific commit it's pointed to. This essentially can be thought of as another repo inside of the parent that makes pushing changes back to the remote repo much easier but at the cost of making pulling/updating from it a little bit more difficult.
NuGet packages are extremely convenient to install, update, and release to others without having to make the source code public, but that comes with a bit more initial setup to generate each package version and comes at the cost of making it more difficult to debug than with the actual source code. This is particularly a great option if the shared code library will be distributed to others.
For most projects, if changes are expected to be potentially made to that shared project from a consuming one I'd recommend a repo for each project and set up the shared one as a submodule in each. It does take a bit of learning to get used to the different processes of checking out and updating a submodule but actually isn't all that difficult and worth learning the few git commands required. The docs provide a great example of how to get started using submodules.

Related

Least-impact solution to binary references in VCS

We are using TeamCity 2017.1 and have been using it for years with great joy. A long time ago, someone decided that all third-party binaires should be put into Subversion (our VCS of choice).
This has worked fine, but over time this repos has grown quite large, and combined with our being better and better at using TeamCity, we now have dozens of build configurations which all uses third-party binaries.
Our third-party folder is called Department and is around 2.6 GB in size. As such this is not so bad, but remember that this folder is used by pretty much every single project on the build server!
Now, I will agree with everyone that says that we should use Nugets, network shares etc., and that would work great with new projects. However, we have a lot of history and we cannot begin to change every single solution and branch.
A co-worker came up with the idea, that IF we made a single build project that in reality did nothing but keep a single folder updated with our Department stuff. Then we just need to find a way to reference this, without have to change all our projects and solutions.
My initial though is using Snapshot dependencies and then create a symbolic link as the first build step and remove it as the last, in order to achieve the same relative levels.
But is there a better way? What do other people do?
And keep in mind, that replacing with nugets or something else is not an option.
Let me follow the idea of your colleague and improve it. There would be a build configuration that monitors the Subversion repository and copies packages to a network share. That network share will be used by development teams as nuget repository. Projects that will convert their dependencies from Binary reference to nuget reference will enjoy faster build. When all the teams will use nuget repositories you may kill that Subversion.

Maintaining upstream vendor source with Xcode and SVN

Question: What is the best way to maintain a project based on another OSS project, through Xcode and version managed by SVN?
I'd like to start a fork (?) of a reasonably popular open source project (it's allowed). Mostly, I want to build my own user interface written in Cocoa/ObjC for it and throw in a few custom features of my own as well.
Now, this OSS project isn't exactly small. The project itself has over 3000 files, and the build process is pretty intense- consisting of multiple stages and steps, which need to compile build tools, run those, then compile the results.
All this is fine and dandy in Xcode, since it's easy enough to setup build phases and rules to handle everything.
What I'm not clear on, is how best to manage patches from upstream. They are constantly working on the project and I'd like to be able to keep up to date with those patches as easily as possible, as many of the diff files effect sometimes up to a hundred (!) files at once.
So maintaining a pristine unmodified copy of that source tree so I can apply patches to it seems like a smart thing to do, because I really don't want to be sorting through hundreds of files every few weeks merging patches by hand.
What I'm thinking of doing in this regard is:
1) Setup an "upstream" SVN repo to hold a copy of the upstream source, plus the bare minimum required to compile it in Xcode (so an xcproject, a few xcconfigs, some prefix header files and that's it)
2) Setup my own "downstream" SVN repo where I do all my work and apply my own modifications.
Whenever upstream releases a patch, I can apply it to #1 then synchronize across to #2, and deal with any issues created by my own modifications.
What I'm not clear about, is if this is a sane way of handling things- or if there's some better practice I should be following.
Is this the best way to handle things, or should I be looking at doing this some other way?
In SVN-world it was named "Vendor Branches" long time ago and intensively used by many teams (you can additionally google this phrase)
Technically it's
one SVN repo
at least one special branch (special in terms of usage, nothing more), which, with svn:externals, linked to 3-rd party repo of upstream code
your place for changes (trunk or any other place, I prefer trunk), initially created as copy of vanilla code and there you perform all code-hacks
If (or "when") vendor branch got updates from upstream, you have just merge branch to /your place/, integrate changes and continue to work

Good Directory Layout for .NET Projects with libraries used across applications and using Mercurial

I've been using Mercurial for a bunch of standalone projects. But now I'm looking at converting a subversion repository to Mercurial thats a lot more busy / complicated.
Given about 40 Library projects and about 20 Applications ( various web / console / wpf, etc) or so. Various apps make use of various Libs. All of this is structured under 1 trunk in subversion. So there's a directory where all the libs live, and a directory where all the apps live. Very easy to find and reference the libs when creating a new Visual Studio Projects.
simplified....
--trunk-|-- libs
|-- apps
Now moving to mercurial, this is less ideal, it seems the way to handle this is with 1 repository for each app? and sub repositories per each lib you want to use?
--app repository-|-- libs
|-- app
Is this right?
If so, when starting a new application in visual studio and you want to add various libs, whats the best/most efficient way to go about it?
I'm getting the feeling the initial setup is a bit painful? As opposed to the subversion layout where effectively you don't really have to do anything other than reference the library in your visual studio project.
So, hence this question, wanting to know a good directory structure, and how to quickly setup a new project using this structure.
Ideally, and this is going to be based on my own opinion and experience in working with larger, distinct applications, but with dependencies, you want to have a repository per distinct, unrelated project, and keep related, possibly dependent projects within the same repo. I'm not a big fan of Subrepositories, but that might just be to lack of exposure.
The reason for this is that you should want to version related projects together as changing one may affect the other. In reality, anything that can be pulled into a single solution and have project references, you definitely want to keep together.
Now, there are some exceptions where you may have a library project that you can't necessarily have as part of a solution, but is a reference for a set of projects. This is where I'd keep a lib folder versioned along side the rest of my applications in the same repo, but the lib folder holds pre-build assemblies. It can also hold 3rd party vendor assemblies as well. This is also important to be versioned along with the project that uses them as you can treat a library update for the main project as a minor release.
For other projects that are truly independent, create another repository for it, as it will have its own version life and you do not want changes to it to affect the graph of changes for your other, completely unrelated projects.
Example layout with several related projects and lib folder:
[-] Big Product Repo
--[-] Big Product 1
----[+] Dal
----[+] Services
----[-] Web
------[+] Controllers
------[+] Models
------[+] Views
--[+] Big Product 2
--[-] lib
----[+] iTextSharp
----[+] nHibernate
Example layout with another unrelated project in it (for sake of argument, a Windows services project):
[-] Small Product Repo
--[-] Windows Services
----[+] Emailer
----[+] Task Runner
In reality, though, your folder structure isn't as important as making sure projects that are being treated as one logical unit (a product) are kept together to ensure control over what is built and released. That is my definition of what a repository should contain and what I use to think about how to split things up if there's more than one versionable product.

Updating multiple projects using svn:externals

Overview
I am using VisualSVN in Visual Studio, VisualSVN Server on Windows, and of course, TortoiseSVN. I wanted to know what the best method of sharing multiple projects over multiple solutions was, and if there was a better method.
Layout
My Repository kind of looks like this (not their real names):
Library.Common
Library.Web
Library.DB
Library.CMS
Customer1.Site
Customer2.Site
Process
To create a new site that contains common projects:
Create Repository in SVN-Server, e.g. "Customer3.Site"
Create Web site using Visual Studio 2008, named "Customer3.Site", VisualSVN used to commit to the repository created in step (1).
Edit properties of Customer3.Site and specify the necessary projects as svn:externals, e.g. "Library.Common", "Library.DB", etc.
Perform an update, to get these external projects, and add them to my solution in Visual Studio, add the necessary references to the Customer3.Site web project and hit build.
So far so good.
The Problem
All this works fine, I am happy that if I have to modify any of the core Library projects I can do so right in the same environment and commit them to the repository. As more and more customer sites are built, I will then have to keep track of what I've done and remember to SVN Update and rebuild those sites which seems quite a long-winded task.
Is there a better way of doing this, a more best-practice solution? Am I breaking any fundamental SVN laws by doing it this way? I want to find a good solution that doesn't cost too much time and isn't overly complex either.
I've been facing a similar issue ... I am setting up a base install package for WordPress, something we would use to quickly get a site setup, it contains the core of wordpress + a set of baseline plugins, both third party and custom ones we've created. Everything pretty much comes from SVN.
Different plugins have different versions/tags and to setup an svn external pointing to a specific tagged version per project would be a nightmare ... only to then have to go into each and every project and do a property adjustment and then an update.
What going to be implementing is a vendor branch with specific versions as needed. All I should then have to do is update the client sites, since they will always be pointing to the latest versions (under my control in the vendor branches).
As to your problem, and also in my case: I would probably write a commit script to update all projects automatically when something in the vendor branch is updated.

Should Git Repo's be at the Solution Level or Project Level in Visual Studio

If I have a C# solution with multiple projects in it, what would be better, to have the Git repo created in the solution folder, or in each individual project folder? Multiple developers will be working on the projects. What are your experiences with this?
I use several (sometimes overlapping) solutions to contain a collection of related independent applications and shared libraries. As others have mentioned, you really don't want to have a single Git repository containing the source for multiple, independent projects as it makes it much too difficult to track isolated changes.
So, if your solution is structured as mine is then you will definitely want individual Git repositories for each project. This has worked well for me for ten to twelve applications and doesn't create as much maintenance overhead as you might think.
If your solution is truly monolithic (and you're sure you want it that way forever and ever), then it probably makes sense to only have a single repository.
It depends. git repositories are most suited to containing a single configuration item with its own independent lifecycle. If your projects have their own release cycle and are shared between multiple solutions then it might make sense to have them in their own repositories. Usually, though, it is the solution that represents a configuration item with all the constituent projects forming part of the same build. In this case a single git repository at the solution level makes more sense.
git submodule is probably worth consideration here. Each project gets its own repo, the solution gets a repo, and the projects are submodules.
I assume that your solution represents some kind of a product while the projects are just a part of the product.
In this situation I would create the repository on the solution level. This way it is a lot easier to build the whole product at once, especially if the projects depend on each other.
Some though and 3 solutions on the subject can be read on that blog:
https://www.atlassian.com/blog/git/git-and-project-dependencies
package management tool, i.e. nuget in VS, so using reference to a package/compiled module
git submodule (only with command line in VS?)
other build and cross-stack dependency tools
Another solution is just to add a project from the other repo and let it out of the current repo, and latter use the Team Explorer to commit its changes.

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