Callback support for acceptFrom

README.md

@@ -244,6 +244,19 @@ In the example the current list `.sortable` allows items within it to be sorted
 
 If you want to be able to move items between to sortables, the `acceptFrom` option must be present on both of them.
 
+Can also accept a callback function with `destinationSortable` and `draggedElement` as paramaters, This function should return `true` or `false`:
+
+``` javascript
+sortable('.sortable', {
+  acceptFrom: function(destinationSortable, draggedElement){
+    if(draggedElement.classList.contains('canDrop')){
+      return true;
+    } else {
+      return false; 
+    }
+  }
+});
+
 ### placeholder
 Use the `placeholder` option to specify the markup of the placeholder:
 

src/html5sortable.ts

@@ -457,7 +457,7 @@ export default function sortable (sortableElements, options: configuration|objec
      * Fires when valid drop target area is hit
      */
     on(sortableElement, 'drop', function (e) {
-      if (!listsConnected(sortableElement, dragging.parentElement)) {
+      if (!listsConnected(sortableElement, dragging)) {
         return
       }
       e.preventDefault()
@@ -622,7 +622,7 @@ export default function sortable (sortableElements, options: configuration|objec
       let element = e.target
       const sortableElement = element.isSortable === true ? element : findSortable(element, e)
       element = findDragElement(sortableElement, element)
-      if (!dragging || !listsConnected(sortableElement, dragging.parentElement) || data(sortableElement, '_disabled') === 'true') {
+      if (!dragging || !listsConnected(sortableElement, dragging) || data(sortableElement, '_disabled') === 'true') {
         return
       }
       const options = data(sortableElement, 'opts')

src/isConnected.ts

@@ -2,29 +2,33 @@ import store from './store'
 /**
  * Check if curList accepts items from destList
  * @param {sortable} destination the container an item is move to
- * @param {sortable} origin the container an item comes from
+ * @param {sortable} dom node currently being dragged
  */
-export default (destination: sortable, origin: sortable) => {
+export default (destination: sortable, dragging: node) => {
   // check if valid sortable
   if (destination.isSortable === true) {
     const acceptFrom = store(destination).getConfig('acceptFrom')
     // check if acceptFrom is valid
-    if (acceptFrom !== null && acceptFrom !== false && typeof acceptFrom !== 'string') {
+    if (acceptFrom !== null && acceptFrom !== false && typeof acceptFrom !== 'string' && typeof acceptFrom !== 'function') {
       throw new Error('HTML5Sortable: Wrong argument, "acceptFrom" must be "null", "false", or a valid selector string.')
     }
 
     if (acceptFrom !== null) {
-      return acceptFrom !== false && acceptFrom.split(',').filter(function (sel) {
-        return sel.length > 0 && origin.matches(sel)
-      }).length > 0
+      if (typeof acceptFrom === 'function') {
+         return acceptFrom(destination, dragging);
+      } else {
+         return acceptFrom !== false && acceptFrom.split(',').filter(function (sel) {
+            return sel.length > 0 && dragging.parentElement.matches(sel)
+         }).length > 0
+      }
     }
     // drop in same list
-    if (destination === origin) {
+    if (destination === dragging.parentElement) {
       return true
     }
     // check if lists are connected with connectWith
-    if (store(destination).getConfig('connectWith') !== undefined && store(destination).getConfig('connectWith') !== null) {
-      return store(destination).getConfig('connectWith') === store(origin).getConfig('connectWith')
+    if ((store(destination).getConfig('connectWith') !== undefined && store(destination).getConfig('connectWith') !== null) && store(dragging.parentElement).getConfig('connectWith') !== undefined && store(dragging.parentElement).getConfig('connectWith') !== null) {
+      return store(destination).getConfig('connectWith') === store(dragging.parentElement).getConfig('connectWith')
     }
   }
   return false