Add Subgraphs (#3905)

Co-authored-by: github-actions <github-actions@github.com>

src/utils/litegraphUtil.ts

@@ -1,6 +1,10 @@
-import type { ColorOption, LGraph } from '@comfyorg/litegraph'
+import { ColorOption, LGraph, Reroute } from '@comfyorg/litegraph'
 import { LGraphGroup, LGraphNode, isColorable } from '@comfyorg/litegraph'
-import type { ISerialisedGraph } from '@comfyorg/litegraph/dist/types/serialisation'
+import type {
+  ExportedSubgraph,
+  ISerialisableNodeInput,
+  ISerialisedGraph
+} from '@comfyorg/litegraph/dist/types/serialisation'
 import type {
   IBaseWidget,
   IComboWidget
@@ -50,6 +54,10 @@ export const isLGraphGroup = (item: unknown): item is LGraphGroup => {
   return item instanceof LGraphGroup
 }
 
+export const isReroute = (item: unknown): item is Reroute => {
+  return item instanceof Reroute
+}
+
 /**
  * Get the color option of all canvas items if they are all the same.
  * @param items - The items to get the color option of.
@@ -163,12 +171,11 @@ export function fixLinkInputSlots(graph: LGraph) {
  * This should match the serialization format of legacy widget conversion.
  *
  * @param graph - The graph to compress widget input slots for.
+ * @throws If an infinite loop is detected.
  */
 export function compressWidgetInputSlots(graph: ISerialisedGraph) {
   for (const node of graph.nodes) {
-    node.inputs = node.inputs?.filter(
-      (input) => !(input.widget && input.link === null)
-    )
+    node.inputs = node.inputs?.filter(matchesLegacyApi)
 
     for (const [inputIndex, input] of node.inputs?.entries() ?? []) {
       if (input.link) {
@@ -179,4 +186,44 @@ export function compressWidgetInputSlots(graph: ISerialisedGraph) {
       }
     }
   }
+
+  compressSubgraphWidgetInputSlots(graph.definitions?.subgraphs)
+}
+
+function matchesLegacyApi(input: ISerialisableNodeInput) {
+  return !(input.widget && input.link === null)
+}
+
+/**
+ * Duplication to handle the legacy link arrays in the root workflow.
+ * @see compressWidgetInputSlots
+ * @param subgraph The subgraph to compress widget input slots for.
+ */
+function compressSubgraphWidgetInputSlots(
+  subgraphs: ExportedSubgraph[] | undefined,
+  visited = new WeakSet<ExportedSubgraph>()
+) {
+  if (!subgraphs) return
+
+  for (const subgraph of subgraphs) {
+    if (visited.has(subgraph)) throw new Error('Infinite loop detected')
+    visited.add(subgraph)
+
+    if (subgraph.nodes) {
+      for (const node of subgraph.nodes) {
+        node.inputs = node.inputs?.filter(matchesLegacyApi)
+
+        if (!subgraph.links) continue
+
+        for (const [inputIndex, input] of node.inputs?.entries() ?? []) {
+          if (input.link) {
+            const link = subgraph.links.find((link) => link.id === input.link)
+            if (link) link.target_slot = inputIndex
+          }
+        }
+      }
+    }
+
+    compressSubgraphWidgetInputSlots(subgraph.definitions?.subgraphs, visited)
+  }
 }