build

build/litegraph.js

@@ -3711,99 +3711,94 @@
         }
 
 		var changed = false;
-
-        //if there is something already plugged there, disconnect
-        if (target_node.inputs[target_slot].link != null) {
-			this.graph.beforeChange();
-            target_node.disconnectInput(target_slot);
-			changed = true;
-        }
-
-        //why here??
-        //this.setDirtyCanvas(false,true);
-        //this.graph.connectionChange( this );
-
-        var output = this.outputs[slot];
-
-        //allows nodes to block connection
-        if (target_node.onConnectInput) {
-            if ( target_node.onConnectInput(target_slot, output.type, output, this, slot) === false ) {
-                return null;
-            }
-        }
-
         var input = target_node.inputs[target_slot];
+        var output = this.outputs[slot];
         var link_info = null;
 
-		//this slots cannot be connected (different types)
-        if (!LiteGraph.isValidConnection(output.type, input.type))
-		{
-	        this.setDirtyCanvas(false, true);
-			if(changed)
-		        this.graph.connectionChange(this, link_info);
-			return null;
-		}
+        if (LiteGraph.isValidConnection(output.type, input.type)) {
+            if (target_node.onBeforeConnectInput) {
+                // This way node can choose another slot (if selected is occupied)
+                target_slot = target_node.onBeforeConnectInput(target_slot);
+            }
 
-		if(!changed)
-			this.graph.beforeChange();
+            //if there is something already plugged there, disconnect
+            if (target_node.inputs[target_slot].link != null) {
+                target_node.disconnectInput(target_slot);
+            }
 
-		//create link class
-		link_info = new LLink(
-			++this.graph.last_link_id,
-			input.type,
-			this.id,
-			slot,
-			target_node.id,
-			target_slot
-		);
+            //why here??
+            //this.setDirtyCanvas(false,true);
+            //this.graph.connectionChange( this );
 
-		//add to graph links list
-		this.graph.links[link_info.id] = link_info;
+            //allows nodes to block connection
+            if (target_node.onConnectInput) {
+                if ( target_node.onConnectInput(target_slot, output.type, output, this, slot) === false ) {
+                    return null;
+                }
+            }
+            if (this.onConnectOutput) {
+                if ( this.onConnectOutput(slot, input.type, input, target_node, target_slot) === false ) {
+                    return null;
+                }
+            }
 
-		//connect in output
-		if (output.links == null) {
-			output.links = [];
-		}
-		output.links.push(link_info.id);
-		//connect in input
-		target_node.inputs[target_slot].link = link_info.id;
-		if (this.graph) {
-			this.graph._version++;
-		}
-		if (this.onConnectionsChange) {
-			this.onConnectionsChange(
-				LiteGraph.OUTPUT,
-				slot,
-				true,
-				link_info,
-				output
-			);
-		} //link_info has been created now, so its updated
-		if (target_node.onConnectionsChange) {
-			target_node.onConnectionsChange(
-				LiteGraph.INPUT,
-				target_slot,
-				true,
-				link_info,
-				input
-			);
-		}
-		if (this.graph && this.graph.onNodeConnectionChange) {
-			this.graph.onNodeConnectionChange(
-				LiteGraph.INPUT,
-				target_node,
-				target_slot,
-				this,
-				slot
-			);
-			this.graph.onNodeConnectionChange(
-				LiteGraph.OUTPUT,
-				this,
-				slot,
-				target_node,
-				target_slot
-			);
-		}
+            link_info = new LLink(
+                ++this.graph.last_link_id,
+                input.type,
+                this.id,
+                slot,
+                target_node.id,
+                target_slot
+            );
+
+            //add to graph links list
+            this.graph.links[link_info.id] = link_info;
+
+            //connect in output
+            if (output.links == null) {
+                output.links = [];
+            }
+            output.links.push(link_info.id);
+            //connect in input
+            target_node.inputs[target_slot].link = link_info.id;
+            if (this.graph) {
+                this.graph._version++;
+            }
+            if (this.onConnectionsChange) {
+                this.onConnectionsChange(
+                    LiteGraph.OUTPUT,
+                    slot,
+                    true,
+                    link_info,
+                    output
+                );
+            } //link_info has been created now, so its updated
+            if (target_node.onConnectionsChange) {
+                target_node.onConnectionsChange(
+                    LiteGraph.INPUT,
+                    target_slot,
+                    true,
+                    link_info,
+                    input
+                );
+            }
+            if (this.graph && this.graph.onNodeConnectionChange) {
+                this.graph.onNodeConnectionChange(
+                    LiteGraph.INPUT,
+                    target_node,
+                    target_slot,
+                    this,
+                    slot
+                );
+                this.graph.onNodeConnectionChange(
+                    LiteGraph.OUTPUT,
+                    this,
+                    slot,
+                    target_node,
+                    target_slot
+                );
+            }
+        }
 
         this.setDirtyCanvas(false, true);
 		this.graph.afterChange();