Load Api on Canvas #1

- Implement api retrieval for a canvas and embed into variables system.
- Implement api calling in SDK and api variables creation from LayoutBuilder.

Author: BirjuVachhani

lib/src/api/models/trigger.dart

@@ -43,7 +43,10 @@ enum TriggerType {
   pointerDown,
 
   /// Triggered when a pointer up event is received on the target.
-  pointerUp;
+  pointerUp,
+
+  /// Triggered when the widget (specifically canvas) is loaded.
+  onLoad;
 
   /// Displayable string representation of the trigger type.
   String get prettify {
@@ -70,6 +73,8 @@ enum TriggerType {
         return 'Editing Complete';
       case TriggerType.submitted:
         return 'Submitted';
+      case TriggerType.onLoad:
+        return 'On Load';
     }
   }
 }

lib/src/api/models/trigger.g.dart

@@ -106,7 +106,7 @@ class VariableData
   VariableData({
     required this.id,
     required this.name,
-    String value = '',
+    Object? value = '',
     this.type = VariableType.text,
   }) : value = sanitizeValueForVariableType(value, type).toString();
 
@@ -356,3 +356,13 @@ class PredefinedVariableData extends VariableData {
     super.type = VariableType.text,
   }) : super(id: generateId());
 }
+
+/// A variable class that represents variables that are created at runtime.
+class RuntimeVariableData extends VariableData {
+  /// Creates a new [PredefinedVariableData].
+  RuntimeVariableData({
+    required super.name,
+    super.value = '',
+    super.type = VariableType.text,
+  }) : super(id: generateId());
+}

lib/src/api/models/variables_model.dart

@@ -41,7 +41,7 @@ class CanvasNode extends ParentNode
   bool get isAScaffold => properties.isAScaffold;
 
   @override
-  List<TriggerType> get triggerTypes => [TriggerType.click];
+  List<TriggerType> get triggerTypes => [TriggerType.onLoad];
 
   @override
   List<ReactionMixin> get reactiveChildren =>