New: Channel setting for Slack notifications to override default channel

Closes #2311

src/NzbDrone.Core/Notifications/Slack/Payloads/SlackPayload.cs

@@ -1,4 +1,4 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using Newtonsoft.Json;
 
 namespace NzbDrone.Core.Notifications.Slack.Payloads
@@ -15,6 +15,8 @@ namespace NzbDrone.Core.Notifications.Slack.Payloads
         [JsonProperty("icon_url")]
         public string IconUrl { get; set; }
 
+        public string Channel { get; set; }
+
         public List<Attachment> Attachments { get; set; }
     }
 }

src/NzbDrone.Core/Notifications/Slack/Slack.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using FluentValidation.Results;
 using NLog;
@@ -107,6 +107,7 @@ namespace NzbDrone.Core.Notifications.Slack
         private SlackPayload CreatePayload(string message, List<Attachment> attachments = null)
         {
             var icon = Settings.Icon;
+            var channel = Settings.Channel;
 
             var payload = new SlackPayload
             {
@@ -128,6 +129,11 @@ namespace NzbDrone.Core.Notifications.Slack
                 }
             }
 
+            if (channel.IsNotNullOrWhiteSpace())
+            {
+                payload.Channel = channel;
+            }
+
             return payload;
         }
     }

src/NzbDrone.Core/Notifications/Slack/SlackSettings.cs

@@ -1,4 +1,4 @@
-using FluentValidation;
+using FluentValidation;
 using NzbDrone.Core.Annotations;
 using NzbDrone.Core.ThingiProvider;
 using NzbDrone.Core.Validation;
@@ -27,6 +27,9 @@ namespace NzbDrone.Core.Notifications.Slack
         [FieldDefinition(2, Label = "Icon", HelpText = "Change the icon that is used for messages from this integration (Emoji or URL)", Type = FieldType.Textbox, HelpLink = "http://www.emoji-cheat-sheet.com/")]
         public string Icon { get; set; }
 
+        [FieldDefinition(3, Label = "Channel", HelpText = "Overrides the default channel for the incoming webhook (#other-channel)", Type = FieldType.Textbox)]
+        public string Channel { get; set; }
+
         public NzbDroneValidationResult Validate()
         {
             return new NzbDroneValidationResult(Validator.Validate(this));