1 files changed, 69 insertions, 0 deletions
diff --git a/csharp/ProtoGen/GeneratorOptions.cs b/csharp/ProtoGen/GeneratorOptions.cs
new file mode 100644
index 00000000..c37352ed
--- /dev/null
+++ b/csharp/ProtoGen/GeneratorOptions.cs
@@ -0,0 +1,69 @@
+using System.Collections.Generic;
+using System.IO;
+
+namespace Google.ProtocolBuffers.ProtoGen {
+
+  /// <summary>
+  /// All the configuration required for the generator - where to generate
+  /// output files, the location of input files etc. While this isn't immutable
+  /// in practice, the contents shouldn't be changed after being passed to
+  /// the generator.
+  /// </summary>
+  public sealed class GeneratorOptions {
+
+    public string OutputDirectory { get; set; }
+    public IList<string> InputFiles { get; set; }
+
+    /// <summary>
+    /// Attempts to validate the options, but doesn't throw an exception if they're invalid.
+    /// Instead, when this method returns false, the output variable will contain a collection
+    /// of reasons for the validation failure.
+    /// </summary>
+    /// <param name="reasons">Variable to receive a list of reasons in case of validation failure.</param>
+    /// <returns>true if the options are valid; false otherwise</returns>
+    public bool TryValidate(out IList<string> reasons) {
+      List<string> tmpReasons = new List<string>();
+
+      // Output directory validation
+      if (string.IsNullOrEmpty(OutputDirectory)) {
+        tmpReasons.Add("No output directory specified");
+      } else {
+        if (!Directory.Exists(OutputDirectory)) {
+          tmpReasons.Add("Specified output directory (" + OutputDirectory + " doesn't exist.");
+        }
+      }
+
+      // Input file validation (just in terms of presence)
+      if (InputFiles == null || InputFiles.Count == 0) {
+        tmpReasons.Add("No input files specified");
+      } else {
+        foreach (string input in InputFiles) {
+          FileInfo fi = new FileInfo(input);
+          if (!fi.Exists) {
+            tmpReasons.Add("Input file " + input + " doesn't exist.");
+          }
+        }
+      }
+
+      if (tmpReasons.Count != 0) {
+        reasons = tmpReasons;
+        return false;
+      }
+
+      reasons = null;
+      return true;
+    }
+
+    /// <summary>
+    /// Validates that all the options have been set and are valid,
+    /// throwing an exception if they haven't.
+    /// </summary>
+    /// <exception cref="InvalidOptionsException">The options are invalid.</exception>
+    public void Validate() {
+      IList<string> reasons;
+      if (!TryValidate(out reasons)) {
+        throw new InvalidOptionsException(reasons);
+      }
+    }
+  }
+}