How to make connection strings available in a T4 template?

Question

I\'ve written a T4 template where I instantiate an EF context to read some data. The problem is that the context cannot see the connection string from the Web.config.

Ho

Answer 1

If anyone needs to resolve absolute path to a Web.config file (because e.g. a .tt file is included and used from multiple other .tt files in different relative paths):

<#@ template debug="true" hostspecific="true" language="C#" #>
<#@ assembly name="EnvDTE" #>
<#@ Assembly Name="System.Configuration" #>
<#@ import namespace="System.IO" #>
<#@ import namespace="System.Configuration" #>
<#+
string GetConnectionString()
{
    var map = new ExeConfigurationFileMap();
    var configPath = Path.Combine(
        Host.ResolveAssemblyReference("$(SolutionDir)"), "WwwFolderInSolution", "Web.config");

    map.ExeConfigFilename = configPath;

    var config = ConfigurationManager.
        OpenMappedExeConfiguration(map, ConfigurationUserLevel.None);

    return config.ConnectionStrings.ConnectionStrings["MyConnectionString"].ConnectionString;
}
#>