Then have a folder with each of your developers have a version in a sub folder (i.e. /_configs/dave/). Then when a developer is working on their own code they copy from the sub folder to the root of the linked folder.
You will need to make sure you communicate changes to these files (unless you tokenise). If you keep the AppSettings.config file out of source control and only check in the devs individual folders (all of them) then they will be forced to copy the correct one.
I prefer tokenisation but can be tougher to get up and running if this is only meant to be a quick fix.
Ignore the files and have a Commom_Web.Config and Common_App.Config. Using a continuous integration build server with build tasks which rename these two to normal names so that the build server can do its job.
In short, what we did was to have a common app.config / web.config, and to have most of the specific settings in individual files, as suggested by other answers here. e.g. for our SMTP settings, the app.config contains
That's not quite where the story ends though. What about new developers, or a fresh source installation? The bulk of the configuration is no longer in source control, and it's a pain to manually build all of the .config files they need. I prefer to have source that will at least compile right out of the box.
Therefore we do keep a version of the .config files in source control, named .config.default files. A fresh source tree therefore looks like this:
Still, not really any use to the developer, since to Visual Studio they're just meaningless text files. Hence the batch file, copy_default_config.bat, takes care of creating an initial set of .config files from the .config.default files:
@echo off
@REM Makes copies of all .default files without the .default extension, only if it doesn't already exist. Does the same recursively through all child folders.
for /r %%f in (*.default) do (
if not exist "%%~pnf" (echo Copying %%~pnf.default to %%~pnf & copy "%%f" "%%~pnf" /y)
)
echo Done.
The script is safely re-runnable, in that developers who already have their .config files will not have them overwritten. Therefore, one could conceivably run this batch file as a pre-build event. The values in the .default files may not be exactly correct for a new install, but they're a reasonable starting point.
Ultimately what each developer ends up with is a folder of config files that looks something like this:
It may seem a little convoluted, but it's definitely preferable to the hassle of developers stepping on each other's toes.
Assuming you are using Visual Studio, why don't you use different Solution Configurations?
For example: you can have a Debug config which uses Web.config.debug and a Release config which uses Web.config.release. Web.config.debug should have something like
with the file Standard_Name_For_Config.config that gots all the personal developer settings, while the Web.config.release always has the production settings.
You can store default configs in some source controlled folder and make a new user take them from there.
This target will transform the Web.config file corresponding to the current developer logged in - hence the $(USERNAME) variable -, with the corresponding file created in 1).
It will replace the local Web.config only if the content has changed (to avoid restart) at each build, even if the local Web.config is source controlled, that's why there is the OverwriteReadOnlyFiles is set to True. This point in fact is arguable.
2) Create a file named Web.[developer windows login].config for each developer in the project. (for example in the following screenshots I have two developers named smo and smo2):
These files (1 per developer) can/should be source-controlled. They should not be marked as dependent on the main Web.config because we want to be able to check them out individually.
Each of this file represent a transformation to apply to the main Web.Config file.
The transformation syntax is described here: Web.config Transformation Syntax for Web Application Project Deployment. We reuse this cool Xml file transformation task that comes out-of-the-box with Visual Studio. The purpose of this task is merge Xml elements and attributes instead of overwriting the whole file.
For example, here is a sample web.[dev login].config that changes a connection string named 'MyDB', regardless of the rest of the Web.config file: