JENKINS-46472 Ability to modify offline cause for offline computers.

Added ability to modify offline cause for offline computers.

ComputerWithDetails computer = ...
if (!computer.getOffline()){
  computer.toggleOffline();
  computer.changeOfflineCause("Scheduled for termination");
}

Author: Jesper Terkelsen

ReleaseNotes.md

@@ -2,6 +2,18 @@
 
 ## Release 0.3.8 (NOT RELEASED YET)
 
+ * [JENKINS-46472](https://issues.jenkins-ci.org/browse/JENKINS-46472)
+
+   Added ability to modify offline cause for offline computers.
+
+   ```java
+    ComputerWithDetails computer = ...
+    if (!computer.getOffline()){
+      computer.toggleOffline();
+      computer.changeOfflineCause("Scheduled for termination");
+    }
+   ```
+
  * [Fixed Issue 268][issue-268]
 
    NullPointerException is thrown unless isRunning() is called first.

jenkins-client/src/main/java/com/offbytwo/jenkins/model/ComputerWithDetails.java

@@ -97,6 +97,23 @@ public void toggleOffline() throws IOException {
         toggleOffline( false );
     }
 
+    public void changeOfflineCause(String cause, boolean crumbFlag) throws IOException {
+      String name;
+      if ("master".equals(displayName)) {
+        name = "(master)";
+      } else {
+        name = UrlEscapers.urlPathSegmentEscaper().escape(displayName);
+      }
+
+      Map<String, String> data = new HashMap<String, String>();
+      data.put( "offlineMessage", cause );
+      client.post_form("/computer/" + name + "/changeOfflineCause?", data, crumbFlag);
+    }
+
+    public void changeOfflineCause(String cause) throws IOException {
+      changeOfflineCause(cause, false);
+    }
+
     public Boolean getManualLaunchAllowed() {
         return manualLaunchAllowed;
     }