Create Interpolated String From a File

[rspiet]

I have lengthy email body templates that I keep in separate data files. These templates contain the String.Format parameters {0}, {1}, etc. As I have numerous of these variables it becomes cumbersome and error prone to use String.Format. I would like to put named variables in the template files. I can't figure out how to do this with an interpolated string as I can't create an interpolated string from a string variable.

Can anyone think of a good way to accomplish this?

[dday9]

Basically you're wanting to build a mail merge. I've done this in the past by setting up a dictionary where the key represents the mail merge parameter and the value represents the value needed to be injected into the body. I tended to wrap the keys in square brackets but you could use curly brackets like in your String.Format style.

Take a look at this example:

Private Function ReplaceMailMerge(body As String) As String
    Dim supportedMailMergeParameters = New Dictionary(Of String, String)() From {
        {"Mail Merge 1", "Foo"},
        {"Mail Merge 2", "Bar"},
        {"Etc", "Etc..."}
    }

    For Each supportedMailMergeParameter In supportedMailMergeParameters
        Dim mailMergeParameter = $"{{{supportedMailMergeParameter.Key}}}"
        Dim mailMergeValue = supportedMailMergeParameter.Value

        body = body.Replace(mailMergeParameter, mailMergeValue)
    Next

    Return body
End Function

Using that Function would turn this string:

Oh {Mail Merge 1}, can I just get a {Mail Merge 2} or {Etc}

Into this:

Oh Foo, can I just get a Bar or Etc...

Live Demo: https://dotnetfiddle.net/9rpDwB

[rspiet]

Thanks. I think that will work for me.