dojo/store/Memory: make put() support "parent" and "before" options

[bill]

As ​the doc explains, stores can support inserting an item as a specific child of another item (as opposed to the last child. dojo/store/Memory doesn't support this. But it's needed for dijit/Tree. (Currently the DnD example of Tree, dijit/tests/tree/test_tree_Dnd.html, is running off of ItemFileWriteStore due to this limitation.)

A colleague (Anthony Erwin, IBM, CCLA) created a subclass of Memory to support it, perhaps you can use that code as a base. Obviously you would need tests too.

         // Need to override put to support DnD and node ordering
        put: function (object, options){
             if (options) {
                         // Per tree example online:
                         //             To support DnD, the store must support put(child, {parent: parent}).
                         //     Since memory store doesn't, we hack it.
                         //     Since our store is relational, that just amounts to setting child.parent
                         //     to the parent's id. 
                         if  (options.parent){
                                object.parent = options.parent.id;
                                
                                 //Another hack to cause items moved into a new parent to show up as the 
                                 //last child of the parent
                                 if  (!options.before) {
                                         this .remove(object.id);
                                }
                        }
                        
                         // What the examples don't tell you is that to support betweenThreshold on the tree
                         // (and support setting the order of nodes), we also need to deal with the "before"
                         // attribute (passed in by model's newItem and pasteItem implementations). So, hacking that
                         // in as well.
                         if  (options.before) {
                                data = this .data;
                                index = this .index,
                                idProperty = this .idProperty;
                                 var  id = object[idProperty] = (options && "id"   in  options) ? options.id : idProperty in  object ? object[idProperty] : Math.random();
                                 if (id in  index){                                     
                                         //Remove the object from its current position
                                         this .remove(id);
                                }
                                 //Insert/add it in right position
                                index = this .index; //there's a re-index after the remove operation
                                 var  beforeRefId = options.before.id;
                                 if (beforeRefId in  index){
                                         //carve out a spot for the new item
                                        data.splice(index[beforeRefId], 0, object);
                                         // now we have to reindex
                                         this .setData(data);
                                }
                        }
            }
             return   this .inherited(arguments);
        }

[bill]

Marking this for 2.0 since we will need it by then for Tree, since dojo/data is presumably going away.

[sunxcint]

I added a patch. I do not update dijit/tests/tree/test_tree_Dnd.html. But I tested a memory-based Dnd tree with the new memory code locally and it works well.

[sunxcint]

Path for dojo/store/Memory

[sunxcint]

Patch for Memory store.

[sunxcint]

Memory.patch and Memory.2.patch are virtually from the same file.

[Denis Rykov]

Is this patch reflects only one approach when children knows about their parent? In my case some of objects has "children" property, but children doesn't know about parents.

[dylan]

This is handed in dstore ( ​http://dstorejs.io/ ), the successor of dojo/store.

[dylan]

Ticket planning... move current 1.12 tickets out to 1.13 that likely won't get fixed in 1.12.