If I want to enable a new piece of functionality to a subset of known users first, is there any automated system of framework that exists to do this?
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74answers:
5
A:
I don't know what "switching between them at runtime" means. You usually don't check executable code into an SCM system. There's a separate process to check out, build, package, and deploy. That's the province of continuous integration and automated builds in agile techniques.
SCM systems like Subversion allow you to have tags and branches for parallel development. You're always free to build, package, and deploy those as you see fit.
duffymo
2010-06-28 01:05:57
A:
As far as I know no...
If you wanted a revision control system that had multiple versions that you could switch between. Find a SCM you like and lookup branching.
But, it sounds like you want it to me able to switch versions in the SCM programmatically during runtime. The problem with that is, for a revision control system to be able to do that it would have to be aware of the language and how it's implemented.
It would have to know how load and run the next version. For example, if it was C code it would have to dynamically compile and run it on the fly. If it was PHP it would have to magically load the script in a sandbox http server that has PHP support. Etc... In which case, it isn't possible.
You can write an app to change the version in the scm by using the command line.
To do it during runtime, that functionality has to be part of the application itself.
Evan Plaice
2010-06-28 01:10:42
A:
The best (only) way I can think of doing it is to have one common piece of code that acts like a 'bootloader', which uses a system call to checkout the correct branch based on whatever your requirements are. It then (if necessary) compiles that code, and runs it.
It's not technically 'at runtime', but it appears that way if it works.
Your first other option is something that dynamically loads code, but that's very language-dependent, and you'd need to specify.
The other is to permanently have both in the working codebase (which doubles your size if it's a full duplication), and switch at runtime. You can save a good bit of space by using objects that are shared between both branches, and things like conditional compilation to use the same source files for both targets.
zebediah49
2010-06-28 01:27:06
+2
A:
Perhaps not directly with version control - you might be interested to read how flickr goes about selectively deploying functionality: http://code.flickr.com/blog/page/2/
And this guy talks about implementing something similar in a rails app: http://www.alandelevie.com/2010/05/19/feature-flippers-with-rails/
Andrew
2010-06-28 01:47:34
Flags and Flippers! seems interesting but looks like there will be helluva if statements to manage.
CodeToGlory
2010-06-28 02:04:34
sure! There might be a more elegant way to manage it, depending on what language/framework/etc you are using.
Andrew
2010-06-28 02:24:39