Using a DataGrid + Repeating Panel to Delete/Edit records

[dconnell]

I’m having difficulty in communicating up and down the ‘stack’ of forms, etc. I have data grids with repeating panels, where I display contents of datatables. For CRUD operations, have the columns with links for delete and edit. Those work just fine, but I cannot figure out how to have those links’ code in the rowtemplate then trigger a refresh of the repeating panel in the parent form. I’ve read about creating custom events, but for the life of me I cannot figure this out.

[p.colbert]

The trick with custom events is getting a direct reference to the exact component (ancestor form) that will respond to them.

Finding the outermost form is easy: The top-level Form. So you could assign such a reference as a member of the outermost form’s tag member.

[campopianoa]

In general, these are some posts that I read for help dealing with “reaching back” and around with repeating panels.

Nested repeating panel, get item(s) when checked

Hello, Just some general information that I reference often that might help. This post contains lots of nice info on “reaching back” to parent forms to access their components. You can also store methods on forms and “reach back” to call them. In your case, having looked very quickly, you may need to do some of this to access the parent form/component. You may also search the forum for related terms (like parent form, outer form, get_open_form, etc…). I hope this helps to point you in the …

[dconnell]

Thanks folks - I’ll read up, test, and update on progress

[owen.campbell]

My Publish-Subscribe Messaging library is another option.

[dconnell]

First: Thanks to all for suffering my stumbling through all of this.

I’ve explored the posts, documentation, etc., and while I better understand some things, I’m still vexed as to how to trigger a refresh of my repeating panel’s items. I believe it’s because I’m operating out of a form embedded in another form, hopefully this diag illustrates what I’m trying to accomplish. My app is too complex (I think) to simply post a clone link.

[stucork]

based on your component structure you could do

def delete_link_clicked(self, **event_args):
    self.parent.items = anvil.server.call_s('get_rows')

I’m always weary about getting too attached to parents though! (especially when you start using parent.parent)

The above code might mean you’ll end up writing the same anvil.server.call_s function more times than you would like.

you might generalise this with a custom event on the repeating panel

# inside SysAdminForm

def __init__(self, **properties):
    ...
    self.repeating_panel.set_event_handler('x-update', self.update)

def update(self, **event_args):
    self.repeating_panel.items = anvil.server.call_s('get_rows')

and then the delete click inside the RowPanel becomes

def delete_click(self, **event_args):
    self.parent.raise_event('x-update')

Once you realise you need to propagate events beyond a single parent then @owen.campbell’s subscriber library is a great dependency to look at!

you might also find this thread helpful

State management in large applications

Hello everyone. I wondering about what strategies people are using to manage component state and communicate changes among components. I find myself doing a lot of self.parent.parent.parent.raise_event, and trying to guess how many levels up the parent is, or when trying to communicate with siblings, doing self.parent...raise_event_in_children - and then having to listen for that event and keep passing it down until I hit the right level. The docs say to use get_form() and then raise an event,…

[dconnell]

I went with your first suggestion. If I ever get to a point when I’m not struggling against deadlines… I’ll explore the other options and suggestions, especially the messaging solution. As always, thanks so very much.