feat(core): add onError hook

Signed-off-by: braks <78412429+bcakmakoglu@users.noreply.github.com>

packages/core/src/container/EdgeRenderer/EdgeRenderer.vue

@@ -19,6 +19,7 @@ const {
   getEdgeTypes,
   elevateEdgesOnSelect,
   dimensions,
+  emits,
 } = $(useVueFlow())
 
 const sourceNode = controlledComputed(
@@ -75,7 +76,7 @@ function getType(type?: string, template?: GraphEdge['template']) {
 
   const slot = slots?.[`edge-${name}`]
   if (!slot) {
-    warn(`Edge type "${type}" not found and no edge-slot detected. Using fallback type "default".`)
+    emits.error(new VueFlowError(ErrorCode.EDGE_TYPE_MISSING, edgeType))
     return false
   }
 

packages/core/src/container/NodeRenderer/NodeRenderer.vue

@@ -68,7 +68,7 @@ function getType(type?: string, template?: GraphNode['template']) {
 
   const slot = slots?.[`node-${name}`]
   if (!slot) {
-    warn(`Node type "${type}" not found and no node-slot detected. Using fallback type "default".`)
+    emits.error(new VueFlowError(ErrorCode.NODE_TYPE_MISSING, nodeType))
     return false
   }
 

packages/core/src/container/Viewport/Viewport.vue

@@ -287,7 +287,9 @@ function setDimensions() {
 
   const { width, height } = getDimensions(viewportEl.value)
 
-  if (width === 0 || height === 0) warn('The Vue Flow parent container needs a width and a height to render the graph.')
+  if (width === 0 || height === 0) {
+    emits.error(new VueFlowError(ErrorCode.MISSING_VIEWPORT_DIMENSIONS))
+  }
 
   dimensions.width = width || 500
   dimensions.height = height || 500