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Showing posts from February, 2023

Use PostConfigure For Default Configuration of Collections in ASP.NET

This post contains a couple of topics that came together in a recent update I was making - one a gotcha, and one a solution, that as well as addressing this issue has wider application. In my web application there was some configuration that consisted of a list of elements. This was represented in code with a POCO like this: Which can then be injected using IOptions<MySettings> into the classes that need it. And in configuration, via the appSettings.json file, you can provide the values: So far so good, but now I wanted to set some default values for this configuration. If nothing is provided, I wanted a non-empty list to be used as the default. But if the user has configured something for the setting, then that should be used. I figured I could just do the following, setting an initial collection on the class, which would be use unless overridden by a value provided in configuration: Unfortunately this doesn't work as I expected as was pointed out to me