Read storage connection string from Configuration

[csbac]

When deploying on Azure, it often makes sense not to put storage connection strings into source code. It is possible to configure them as part of the portal service configuration.
They can then be access via ConfigurationManager.ConnectionStrings.

The following patch allows to use

<appender name="AzureTableAppender" ....>
  <param name="ConnectionStringName" value="XXX" />

when configuring AzureTableAppender, and use the same connection definition XXX that is used in other places in the code, anyway.

--- a/log4net.Azure/AzureTableAppender.cs
+++ b/log4net.Azure/AzureTableAppender.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Configuration;
 using System.Linq;
 using log4net.Appender.Extensions;
 using log4net.Appender.Language;
@@ -14,12 +15,19 @@ public class AzureTableAppender : BufferingAppenderSkeleton
         private CloudTableClient _client;
         private CloudTable _table;

+        public string ConnectionStringName { get; set; }
         private string _connectionString;

         public string ConnectionString
         {
             get
             {
+                if (!string.IsNullOrWhiteSpace(ConnectionStringName))
+                {
+                    var config = ConfigurationManager.ConnectionStrings[ConnectionStringName];
+                    if (config != null)
+                        return config.ConnectionString;
+                }
                 if (String.IsNullOrEmpty(_connectionString))
                     throw new ApplicationException(Resources.AzureConnectionStringNotSpecified);
                 return _connectionString;

[csbac]

Ah, you also need

diff --git a/log4net.Azure/log4net.Appender.Azure.csproj b/log4net.Azure/log4net.Appender.Azure.csproj
index 854f7f4..6d947f6 100644
--- a/log4net.Azure/log4net.Appender.Azure.csproj
+++ b/log4net.Azure/log4net.Appender.Azure.csproj
@@ -67,6 +67,7 @@
       <HintPath>..\packages\Newtonsoft.Json.6.0.8\lib\net45\Newtonsoft.Json.dll</HintPath>
     </Reference>
     <Reference Include="System" />
+    <Reference Include="System.Configuration" />
     <Reference Include="System.Core" />
     <Reference Include="System.Data" />
     <Reference Include="System.Spatial, Version=5.6.4.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">

[stemarie]

Very nice change, thanks

I'll put this in and update the NuGet package as soon as possible