feat(blocks): Add depends_on support for input fields (#8852)

- Resolves part of #8731 

### Changes
- Added `depends_on` parameter to SchemaField in `model.py` to specify
field dependencies.
- Updated `useAgentGraph` hook to validate input fields based on their
dependencies, ensuring required fields are set when dependent fields are
filled.
- Modified `BlockIOSubSchemaMeta` to include `depends_on` as an optional
property.



https://github.com/user-attachments/assets/64fd47b3-34dc-48fa-ad90-1c9c5cd4c4a3

---------

Co-authored-by: Zamil Majdy <zamil.majdy@agpt.co>
Co-authored-by: Nicholas Tindle <nicholas.tindle@agpt.co>

autogpt_platform/backend/backend/data/graph.py

@@ -257,7 +257,7 @@ class GraphModel(Graph):
         for link in self.links:
             input_links[link.sink_id].append(link)
 
-        # Nodes: required fields are filled or connected
+        # Nodes: required fields are filled or connected and dependencies are satisfied
         for node in self.nodes:
             block = get_block(node.block_id)
             if block is None:
@@ -278,6 +278,38 @@ class GraphModel(Graph):
                         f"Node {block.name} #{node.id} required input missing: `{name}`"
                     )
 
+            # Get input schema properties and check dependencies
+            input_schema = block.input_schema.model_fields
+            required_fields = block.input_schema.get_required_fields()
+
+            def has_value(name):
+                return (
+                    node is not None
+                    and name in node.input_default
+                    and node.input_default[name] is not None
+                    and str(node.input_default[name]).strip() != ""
+                ) or (name in input_schema and input_schema[name].default is not None)
+
+            # Validate dependencies between fields
+            for field_name, field_info in input_schema.items():
+
+                # Apply input dependency validation only on run & field with depends_on
+                json_schema_extra = field_info.json_schema_extra or {}
+                dependencies = json_schema_extra.get("depends_on", [])
+                if not for_run or not dependencies:
+                    continue
+
+                # Check if dependent field has value in input_default
+                field_has_value = has_value(field_name)
+                field_is_required = field_name in required_fields
+
+                # Check for missing dependencies when dependent field is present
+                missing_deps = [dep for dep in dependencies if not has_value(dep)]
+                if missing_deps and (field_has_value or field_is_required):
+                    raise ValueError(
+                        f"Node {block.name} #{node.id}: Field `{field_name}` requires [{', '.join(missing_deps)}] to be set"
+                    )
+
         node_map = {v.id: v for v in self.nodes}
 
         def is_static_output_block(nid: str) -> bool:

autogpt_platform/backend/backend/data/model.py

@@ -138,6 +138,7 @@ def SchemaField(
     secret: bool = False,
     exclude: bool = False,
     hidden: Optional[bool] = None,
+    depends_on: list[str] | None = None,
     **kwargs,
 ) -> T:
     json_extra = {
@@ -147,6 +148,7 @@ def SchemaField(
             "secret": secret,
             "advanced": advanced,
             "hidden": hidden,
+            "depends_on": depends_on,
         }.items()
         if v is not None
     }

autogpt_platform/frontend/src/hooks/useAgentGraph.ts

@@ -404,6 +404,54 @@ export default function useAgentGraph(
           }
         });
       }
+
+      Object.entries(node.data.inputSchema.properties || {}).forEach(
+        ([key, schema]) => {
+          if (schema.depends_on) {
+            const dependencies = schema.depends_on;
+
+            // Check if dependent field has value
+            const hasValue =
+              inputData[key] != null ||
+              ("default" in schema && schema.default != null);
+
+            const mustHaveValue = node.data.inputSchema.required?.includes(key);
+
+            // Check for missing dependencies when dependent field is present
+            const missingDependencies = dependencies.filter(
+              (dep) =>
+                !inputData[dep as keyof typeof inputData] ||
+                String(inputData[dep as keyof typeof inputData]).trim() === "",
+            );
+
+            if ((hasValue || mustHaveValue) && missingDependencies.length > 0) {
+              setNestedProperty(
+                errors,
+                key,
+                `Requires ${missingDependencies.join(", ")} to be set`,
+              );
+              errorMessage = `Field ${key} requires ${missingDependencies.join(", ")} to be set`;
+            }
+
+            // Check if field is required when dependencies are present
+            const hasAllDependencies = dependencies.every(
+              (dep) =>
+                inputData[dep as keyof typeof inputData] &&
+                String(inputData[dep as keyof typeof inputData]).trim() !== "",
+            );
+
+            if (hasAllDependencies && !hasValue) {
+              setNestedProperty(
+                errors,
+                key,
+                `${key} is required when ${dependencies.join(", ")} are set`,
+              );
+              errorMessage = `${key} is required when ${dependencies.join(", ")} are set`;
+            }
+          }
+        },
+      );
+
       // Set errors
       setNodes((nodes) => {
         return nodes.map((n) => {

autogpt_platform/frontend/src/lib/autogpt-server-api/types.ts

@@ -56,6 +56,7 @@ export type BlockIOSubSchemaMeta = {
   description?: string;
   placeholder?: string;
   advanced?: boolean;
+  depends_on?: string[];
   hidden?: boolean;
 };