How to refer to main domain without hard-coding its name?

Question

I have a domain name: TestSite.com. I create several subdomains for this site and refer to them as first.TestSite.com, second.TestSite.com, etc.

How do I refer to TestSi

Answer 1

Since you tagged your question ASP.NET, I'm going to assume you want to do this server-side, so you are not relying on JavaScript on the client-side to generate HTML links.

First of all, make sure you have a web.config file in your subdomain sites, and add this to the configuration:

Using this setting in your ASPX pages, hyperlinks on one of your subdomains' pages would look like this:

Go to main domain home page
Go to products page on the main domain

The setting with name="MainDomain" will be read from the configuration file, and inserted into the page where it says <%$ AppSettings: MainDomain %>. This way, you are creating the required HTML on the server-side, with no hard-coding required.

If you need to change the name, simply update the configuration file, and all pages will automatically use the new domain name.