{"id":8109,"date":"2023-04-04T10:54:59","date_gmt":"2023-04-04T17:54:59","guid":{"rendered":"https:\/\/visualgdb.com\/w\/?p=8109"},"modified":"2023-04-04T11:00:20","modified_gmt":"2023-04-04T18:00:20","slug":"parsing-lists-of-objects-in-live-watch-plugins","status":"publish","type":"post","link":"https:\/\/visualgdb.com\/tutorials\/extensibility\/livewatch\/lists\/","title":{"rendered":"Parsing Lists of Objects in Live Watch Plugins"},"content":{"rendered":"

This tutorial shows how to use the Live Watch plugins to discover and show all variables of a particular type, whether created statically or dynamically. We will extend a basic Live Watch plugin from this tutorial<\/a> that locates the g_Counter<\/strong> variable and creates a custom Live Watch node for it. Instead of looking for a particular variable, we will create the nodes for all variables of the SampleCounter<\/strong> type, and even discover dynamically allocated instances by traversing linked lists.<\/p>\n

Before you begin, clone this git tag<\/a>, or simply follow our previous tutorial<\/a> to get a basic live watch plugin working.<\/p>\n

    \n
  1. Open the SampleLiveWatchExtension<\/strong> project from this tutorial<\/a>. Locate the CounterListNode.GetChildren()<\/strong> method that creates a node for g_Counter<\/strong>, and replace it with the code shown below:\n
    var result = new List<ILiveWatchNode>();\r\n\r\nforeach(var v in _Engine.Symbols.TopLevelVariables)\r\n{\r\n\tif (v.RawType.Resolved == \"SampleCounter\")\r\n\t{\r\n\t\tresult.Add(new CounterNode(_Engine, v));\r\n\t}\r\n}\r\n\r\nreturn result.ToArray();<\/pre>\n
    \"\"<\/a>Note how we are iterating through all global\/static variables, checking their resolved type (i.e. resolving typedefs), and creating nodes for all variables that have a matching type.<\/li>\n
  2. Press F5 to start debugging the plugin. When the second instance of Visual Studio launches, open the SampleLiveWatchProject<\/strong> project in it, rename g_Counter<\/strong> to g_Counter1<\/strong> and add a g_Counter2<\/strong> variable next to it. Make sure you assign the Name<\/strong> field for both of them: \"\"<\/a><\/li>\n
  3. Start debugging the embedded project. Note how the Live Watch<\/strong> window now shows both Test counter #1<\/strong> and Test Counter #2<\/strong>:\"\"<\/a> You can use the same technique to discover and present objects of various types. The GetChildren()<\/a> method is normally called only once when the node is expanded for the first time, so you can easily iterate through all global variables in it, find the relevant ones, and create meaningful nodes for them.<\/li>\n
  4. Now we will show how to handle dynamic lists. Add a “SampleCounter *Next<\/strong>” field to the SampleCounter<\/strong> struct, and create a few more instances of it dynamically:\n
        g_Counter1.Next = (SampleCounter *)malloc(sizeof(SampleCounter));\r\n    g_Counter1.Next->Name = \"Dynamic counter #1\";\r\n\r\n    g_Counter1.Next->Next = (SampleCounter *)malloc(sizeof(SampleCounter));\r\n    g_Counter1.Next->Next->Name = \"Dynamic counter #2\";\r\n\r\n    g_Counter1.Next->Next->Next = NULL;<\/pre>\n
    \"\"<\/a><\/li>\n
  5. We will now modify the CounterListNode<\/strong> class to dynamically parse the linked lists of counters, and show them in the child list. In order to do that, we would need to:\n