splitting out a new tag to configure a TCP/IP port for a daemon

core/src/main/groovy/jenkins/util/ServerTcpPort.java

+package jenkins.util;
+
+import net.sf.json.JSONObject;
+import org.kohsuke.stapler.DataBoundConstructor;
+
+/**
+ * Used in conjunction with /lib/form/serverTcpPort tag to parse the submitted JSON back into a port number.
+ *
+ * @author Kohsuke Kawaguchi
+ * @since 1.445
+ */
+public class ServerTcpPort {
+    private int value;
+    private String type;
+
+    @DataBoundConstructor
+    public ServerTcpPort(int value, String type) {
+        this.value = value;
+        this.type = type;
+    }
+    
+    public ServerTcpPort(JSONObject o) {
+        type = o.getString("type");
+        value = o.optInt("value");
+    }
+
+    /**
+     * Parses the value back into the port number
+     */
+    public int getPort() {
+        if (type.equals("fixed"))   return value;
+        if (type.equals("random"))  return 0;
+        return -1;
+    }
+}

core/src/main/java/hudson/security/GlobalSecurityConfiguration.java

@@ -27,6 +27,7 @@ import hudson.Extension;
 import hudson.markup.MarkupFormatter;
 import jenkins.model.GlobalConfiguration;
 import jenkins.model.Jenkins;
+import jenkins.util.ServerTcpPort;
 import net.sf.json.JSONObject;
 import org.kohsuke.stapler.StaplerRequest;
 
@@ -43,34 +44,26 @@ public class GlobalSecurityConfiguration extends GlobalConfiguration {
         return Jenkins.getInstance().getMarkupFormatter();
     }
     
+    public int getSlaveAgentPort() {
+        return Jenkins.getInstance().getSlaveAgentPort();
+    }
+    
     @Override
     public boolean configure(StaplerRequest req, JSONObject json) throws FormException {
         // for compatibility reasons, the actual value is stored in Jenkins
         Jenkins j = Jenkins.getInstance();
 
-        try {
-            String v = req.getParameter("slaveAgentPortType");
-            if(!j.isUseSecurity() || v==null || v.equals("random"))
-                j.setSlaveAgentPort(0);
-            else
-            if(v.equals("disable"))
-                j.setSlaveAgentPort(-1);
-            else {
-                try {
-                    j.setSlaveAgentPort(Integer.parseInt(req.getParameter("slaveAgentPort")));
-                } catch (NumberFormatException e) {
-                    throw new FormException(jenkins.model.Messages.Hudson_BadPortNumber(req.getParameter("slaveAgentPort")),"slaveAgentPort");
-                }
-            }
-        } catch (IOException e) {
-            throw new FormException(e,"slaveAgentPortType");
-        }
-
         if (json.has("useSecurity")) {
             JSONObject security = json.getJSONObject("useSecurity");
             j.setSecurityRealm(SecurityRealm.all().newInstanceFromRadioList(security, "realm"));
             j.setAuthorizationStrategy(AuthorizationStrategy.all().newInstanceFromRadioList(security, "authorization"));
 
+            try {
+                j.setSlaveAgentPort(new ServerTcpPort(security.getJSONObject("slaveAgentPort")).getPort());
+            } catch (IOException e) {
+                throw new FormException(e,"slaveAgentPortType");
+            }
+
             if (security.has("markupFormatter")) {
                 j.setMarkupFormatter(req.bindJSON(MarkupFormatter.class, security.getJSONObject("markupFormatter")));
             } else {

core/src/main/resources/hudson/security/GlobalSecurityConfiguration/config.groovy

@@ -7,28 +7,7 @@ def f=namespace(lib.FormTagLib)
 
 f.optionalBlock( field:"useSecurity", title:_("Enable security"), checked:app.useSecurity) {
     f.entry (title:_("TCP port for JNLP slave agents"), field:"slaveAgentPort") {
-
-        int port = app.slaveAgentPort
-
-        f.radio(name:"slaveAgentPortType", value:"fixed", id:"sat.fixed",
-                checked:port>0, onclick:"\$('sat.port').disabled=false")
-        label("for":"sat.fixed", _("Fixed"))
-        text(" : ")
-        input(type:"number", "class":"number", name:"slaveAgentPort", id:"sat.port",
-                value: port>0 ? port : null, disabled: port>0 ? null : "true",
-                min:0, max:65535, step:1)
-
-        raw(" ") ////////////////////////////
-
-        f.radio(name:"slaveAgentPortType", value:"random", id:"sat.random",
-                checked:port==0, onclick:"\$('sat.port').disabled=true")
-        label("for":"sat.random", _("Random"))
-
-        raw(" ") ////////////////////////////
-
-        f.radio(name:"slaveAgentPortType", value:"disable", id:"sat.disabled",
-                checked:port==-1, onclick:"\$('sat.port').disabled=true")
-        label("for":"sat.disabled", _("Disable"))
+        f.serverTcpPort()
     }
 
     f.dropdownDescriptorSelector(title:_("Markup Formatter"),field:"markupFormatter")

core/src/main/resources/lib/form/serverTcpPort.groovy

+package lib.form
+
+/**
+ * Generates a UI for selecting server TCP/IP port (for some kind of daemon, typically)
+ *
+ * The user can specify a fixed port (1-65535), or let Jenkins allocate random port (0), or disable it (-1).
+ *
+ * On the databinding side, use {@link jenkins.util.ServerTcpPort} to handle this structure back into a single
+ * port number. The getter method should just expose the port number integer.
+ */
+
+
+int port = instance?instance[field]:0;
+
+def f=namespace(lib.FormTagLib)
+
+def type = "${field}.type"
+def id   = "${field}Id" // TODO: get rid of this
+
+div(name:field) {
+    label {
+        f.radio(name: type, value:"fixed",
+                checked:port>0, onclick:"\$('${id}').disabled=false")
+        text(_("Fixed"))
+        text(" : ")
+    }
+    input(type:"number", "class":"number", name:"value", id:id,
+            value: port>0 ? port : null, disabled: port>0 ? null : "true",
+            min:0, max:65535, step:1)
+
+    raw(" ") ////////////////////////////
+
+    label {
+        f.radio(name:type, value:"random",
+                checked:port==0, onclick:"\$('{id}').disabled=true")
+        text(_("Random"))
+    }
+
+    raw(" ") ////////////////////////////
+
+    label {
+        f.radio(name:type, value:"disable",
+                checked:port==-1, onclick:"\$('{id}').disabled=true")
+        text(_("Disable"))
+    }
+}