callagent: Add writing SDP to the datagram

callagent/MGCPCommands.st

@@ -17,7 +17,7 @@
 "
 
 Object subclass: MGCPCommand [
-    | verb transaction endp params |
+    | verb transaction endp params sdp |
     <comment: 'I am a command send to a MGCP gateway. I know my timeout
     and such. Each MGCPGateWay can have a MGCPCommand subclass to specify
     certain things. E.g. the endpoint numbering is different'>
@@ -71,6 +71,16 @@ Object subclass: MGCPCommand [
         ^ params ifNil: [params := OrderedCollection new]
     ]
 
+    sdpAdd: line [
+	<category: 'private'>
+        self sdp add: line.
+    ]
+
+    sdp [
+	<category: 'private'>
+        ^ sdp ifNil: [sdp := OrderedCollection new]
+    ]
+
     asDatagram [
 	| out |
 	<category: 'networking'>
@@ -89,6 +99,18 @@ Object subclass: MGCPCommand [
                 cr; nl.
         ].
 
+        "write optional SDP"
+        sdp ifNotNil: [
+            out
+                cr; nl.
+
+            sdp do: [:each |
+                out
+                    nextPutAll: each;
+                    cr; nl.
+            ].
+        ].
+
         ^ out contents
     ]
 ]