Add Possibility to customize AppendMenuProvider

[AmiciD]

Is your feature request related to a problem? Please describe.

I have an implementation of bpmn-js version 11.1.0 with all compatible plugins for that version.

Upgrading to the new version, I found that the appendMenuProvider to modify the entries of the appendMenu is no longer exported and modifiable in this package.

Describe the solution you'd like

I would prefer an approach similar to the old one, where I could import the provider and modify its behavior.

Describe alternatives you've considered

A working workaround I found is this:

import { CreateAppendAnythingModule } from "bpmn-js-create-append-anything";

const AppendMenuProvider = CreateAppendAnythingModule.__depends__[0].appendMenuProvider[1];

Unfortunately, I haven't found anything regarding this new implementation of the appendMenuProvider; I just need to modify and filter the menu entries.

[nikku]

Thanks for opening this issue. At this stage it is not easily possible to access the appendMenuProvider by sub-classing.

The general way to subclass is not to "modify providers" through sub-classing, but to provide your own customizing AppendMenuProvider:

const LOW_PRIORITY = 500;

function MyAppendMenuModifyingProvider(popupMenu, eventBus) {
  
  // register provider
  popupMenu.registerProvider('bpmn-append', this, LOW_PRIORITY);
  
  // own provider method returns middleware
  // (element) => (existingEntires) => newEntries
  
  this.getPopupMenuEntries = function(element) {
    
    return (existingEntries) => {
      // modify <existingEntries> as you wish, add, remove some
      
      return existingEntries;
    };
  };
}

Would this work for your case?

[nikku]

@AmiciD I'd be interested if #29 (comment) worked for you? I assume so and will close this issue as won't fix.

[AmiciD]

@nikku unfortunately i had no time to look for a custom implementation like the one suggested, i will try and give a feedback here asap