CodeDomProvider.GetLanguageFromExtension(String) Method

Definition

Namespace:

System.CodeDom.Compiler

Assembly:

System.CodeDom.dll

Returns a language name associated with the specified file name extension, as configured in the CodeDomProvider compiler configuration section.

public:
 static System::String ^ GetLanguageFromExtension(System::String ^ extension);

public static string GetLanguageFromExtension (string extension);

static member GetLanguageFromExtension : string -> string

Public Shared Function GetLanguageFromExtension (extension As String) As String

Parameters

extension

String

A file name extension.

Returns

String

A language name associated with the file name extension, as configured in the CodeDomProvider compiler configuration settings.

Exceptions

ConfigurationException

The extension does not have a configured language provider on this computer.

ConfigurationErrorsException

The extension is null.

SecurityException

The caller does not have the required permission.

Examples

The following code example determines the CodeDomProvider implementation for an input file name extension and displays the configured settings for the language provider. This code example is part of a larger example provided for the CompilerInfo class.

if (  !fileExtension->StartsWith(  "." ) )
   fileExtension = String::Concat( ".", fileExtension );

// Get the language associated with the file extension.
CodeDomProvider^ provider = nullptr;
if ( CodeDomProvider::IsDefinedExtension( fileExtension ) )
{
   String^ language = CodeDomProvider::GetLanguageFromExtension( fileExtension );
   if ( language )
      Console::WriteLine( "The language \"{0}\" is associated with file extension \"{1}\"\n",
                           language, fileExtension );

   // Check for a corresponding language provider.
   if ( language && CodeDomProvider::IsDefinedLanguage( language ) )
   {
      provider = CodeDomProvider::CreateProvider( language );
      if ( provider )
      {
         // Display information about this language provider.
         Console::WriteLine( "Language provider:  {0}\n", provider->ToString() );
         
         // Get the compiler settings for this language.
         CompilerInfo^ langCompilerInfo = CodeDomProvider::GetCompilerInfo( language );
         if ( langCompilerInfo )
         {
            CompilerParameters^ langCompilerConfig = langCompilerInfo->CreateDefaultCompilerParameters();
            if ( langCompilerConfig )
            {
               Console::WriteLine( "  Compiler options:        {0}", langCompilerConfig->CompilerOptions );
               Console::WriteLine( "  Compiler warning level:  {0}", langCompilerConfig->WarningLevel.ToString() );
            }
         }
      }
   }
}

if ( provider == nullptr )  // Tell the user that the language provider was not found.
   Console::WriteLine( "There is no language provider associated with input file extension \"{0}\".", fileExtension );

if (fileExtension[0] != '.')
{
    fileExtension = "." + fileExtension;
}

// Get the language associated with the file extension.
if (CodeDomProvider.IsDefinedExtension(fileExtension))
{
    CodeDomProvider provider;
    String language = CodeDomProvider.GetLanguageFromExtension(fileExtension);

    Console.WriteLine("The language \"{0}\" is associated with file extension \"{1}\"",
        language, fileExtension);
    Console.WriteLine();

    // Next, check for a corresponding language provider.

    if (CodeDomProvider.IsDefinedLanguage(language))
    {
        provider = CodeDomProvider.CreateProvider(language);

        // Display information about this language provider.

        Console.WriteLine("Language provider:  {0}",
            provider.ToString());
        Console.WriteLine();

        // Get the compiler settings for this language.

        CompilerInfo langCompilerInfo = CodeDomProvider.GetCompilerInfo(language);
        CompilerParameters langCompilerConfig = langCompilerInfo.CreateDefaultCompilerParameters();

        Console.WriteLine("  Compiler options:        {0}",
            langCompilerConfig.CompilerOptions);
        Console.WriteLine("  Compiler warning level:  {0}",
            langCompilerConfig.WarningLevel);
    }
}
else
{
    // Tell the user that the language provider was not found.
    Console.WriteLine("There is no language provider associated with input file extension \"{0}\".",
        fileExtension);
}

If Not fileExtension.StartsWith(".") Then
   fileExtension = "." + fileExtension
End If

' Get the language associated with the file extension.
If CodeDomProvider.IsDefinedExtension(fileExtension) Then
   Dim provider As CodeDomProvider
   Dim language As String = CodeDomProvider.GetLanguageFromExtension(fileExtension)
   
   Console.WriteLine("The language ""{0}"" is associated with file extension ""{1}""", _
       language, fileExtension)
   Console.WriteLine()
   
   ' Check for a corresponding language provider.
   If CodeDomProvider.IsDefinedLanguage(language) Then
      provider = CodeDomProvider.CreateProvider(language)
      
      ' Display information about this language provider.
      Console.WriteLine("Language provider:  {0}", _
         provider.ToString())
      Console.WriteLine()
      
      ' Get the compiler settings for this language.
      Dim langCompilerInfo As CompilerInfo = CodeDomProvider.GetCompilerInfo(language)
      Dim langCompilerConfig As CompilerParameters = langCompilerInfo.CreateDefaultCompilerParameters()
      
      Console.WriteLine("  Compiler options:        {0}", _
          langCompilerConfig.CompilerOptions)
      Console.WriteLine("  Compiler warning level:  {0}", _
          langCompilerConfig.WarningLevel)
   End If
Else
   ' Tell the user that the language provider was not found.
   Console.WriteLine("There is no language provider associated with input file extension ""{0}"".", fileExtension)
End If

Remarks

The <system.codedom> Element in the machine configuration file (Machine.config) contains the language provider and compiler configuration settings for each CodeDomProvider implementation on the computer. The GetLanguageFromExtension method searches each provider configuration element for the specified file name extension.

The IsDefinedExtension method checks whether at least one provider implementation supports a specific file name extension. You can validate a file name extension using IsDefinedExtension before passing it to GetLanguageFromExtension. This prevents GetLanguageFromExtension from throwing a System.Configuration.ConfigurationException for an unsupported file name extension.

If a provider implementation supports the input file name extension, and there are multiple supported languages configured for that provider, then GetLanguageFromExtension returns the first language name for that provider. If more than one provider implementation is configured for the input file name extension, GetLanguageFromExtension returns the language name from the last matching provider configuration element.

Language names and file name extensions are case-insensitive.

See also

• IsDefinedExtension(String)
• CreateProvider(String)
• Compiler and Language Provider Settings Schema