Deleting an item doesn't clean up its alias [v1.0.2]

[ysicg]

Version of Dear PyGui

Version: 1.0.2
Operating System: Ubuntu 20.04

To Reproduce

Create an item with an alias and delete it:

import dearpygui.dearpygui as dpg

dpg.create_context()
with dpg.window():
    dpg.add_text("", tag="an_alias")
    dpg.delete_item("an_alias")
    dpg.does_item_exist("an_alias") #returns False as expected
    if dpg.does_alias_exist("an_alias"):
        print("Kill me please!")

dpg.destroy_context()

Expected behavior

does_alias_exist(alias) to return False, as it did in v0.8.64.

[Pcothren]

it appears that this is only happens when an item is created and deleted before DPG starts that the alias is not cleaned up

import dearpygui.dearpygui as dpg

dpg.create_context()

def check_state():
    dpg.delete_item('an_new_alias')
    print(f"More Text Item (After deleted): {dpg.does_item_exist('an_new_alias')}")
    print(f"More Text Alias (After deleted): {dpg.does_alias_exist('an_new_alias')}")

with dpg.window()as mainWin:
    dpg.add_text("Some Text", tag="an_alias")
    dpg.add_text("More Text", tag="an_new_alias")

    print(f"Some Text Item: {dpg.does_item_exist('an_alias')}")
    print(f"Some Text Alias: {dpg.does_alias_exist('an_alias')}")
    dpg.delete_item('an_alias')
    print(f"Some Text Item (After deleted): {dpg.does_item_exist('an_alias')}")
    print(f"Some Text Alias (After deleted): {dpg.does_alias_exist('an_alias')}")

    dpg.add_button(label="check state", callback=check_state)

dpg.create_viewport()
dpg.show_viewport()
dpg.setup_dearpygui()
dpg.start_dearpygui()
dpg.destroy_context()

[ysicg]

If we delete the whole window instead in check_state(),

dpg.delete_item(mainWin)

Both aliases remain uncleaned.

[hoffstadt]

It appears the aliases are only removed if the app has actually started up. We will need to cover this case.

@ysicg The workaround is to manually remove the alias: dpg.remove_alias("an_alias") after deleting the item.

[Pcothren]

DearPyGui/DearPyGui/src/core/AppItems/mvAppItem.cpp

Lines 50 to 55 in a68b849

	// in case item registry is destroyed
	if (GContext->started)
	{
	RemoveAlias(*GContext->itemRegistry, _alias, true);
	CleanUpItem(*GContext->itemRegistry, _uuid);
	}

commenting out this check will fist this example: #1350 (comment)

probably dig deeper into why this check was implemented and when, could have been before the context was created explicitly in which case it may not be needed anymore, maybe try and find pr and issue that was related to this fix

[Pcothren]

goes back to commit eb80b71 and then is replaced with

DearPyGui/DearPyGui/src/core/AppItems/mvAppItem.cpp

Lines 1078 to 1083 in eb80b71

	// in case item registry is destroyed
	if (GContext->started)
	{
	CleanUpItem(*GContext->itemRegistry, _uuid);
	RemoveAlias(*GContext->itemRegistry, _alias, true);
	}

from

		// in case item registry is destroyed
		if (mvApp::IsAppStarted())
		{
			CleanUpItem(*mvApp::GetApp()->itemRegistry, _uuid);
			RemoveAlias(*mvApp::GetApp()->itemRegistry, _alias, true);
		}

and
mvApp::IsAppStarted()

was originally implemented in 2c6f1b6

[josevnz]

Hello, you can use the following code to reproduce the issue:

#!/usr/bin/env python
#pylint: disable=import-error
#pylint: disable=invalid-name
"""
Simple usage of table with dynamic rows
"""

import dearpygui.dearpygui as dpg


if __name__ == "__main__":
    tag="mytableid"
    dpg.create_context()
    with dpg.window(label="main_window"):
        with dpg.table(header_row=True, resizable=True, tag=tag, parent="main_window"):
            dpg.add_table_column(label="Name", parent=tag)
            dpg.add_table_column(label="Size (bytes)", default_sort=True, parent=tag)
            for row in range(0, 100):
                with dpg.table_row(parent=tag):
                    dpg.add_text("col1")
                    dpg.add_text("col2")
        #dpg.delete_item(tag, children_only=False)
        #dpg.remove_alias(tag)
        with dpg.table(header_row=True, resizable=True, tag=tag):
            dpg.add_table_column(label="Name", parent=tag)
            dpg.add_table_column(label="Size (bytes)", default_sort=True, parent=tag)
            for row in range(0, 4):
                with dpg.table_row(parent=tag):
                    dpg.add_text("col1")
                    dpg.add_text("col2")

    dpg.create_viewport(title='RPM Quick query tool', width=500)
    dpg.setup_dearpygui()
    dpg.show_viewport()
    dpg.start_dearpygui()
    dpg.destroy_context()

If you uncomment the following lines

        dpg.delete_item(tag, children_only=False)
        dpg.remove_alias(tag)

Then the table works fine.

[hoffstadt]

Fixed in next release.

[iBenji]

Still problem exist.
But this issue also could be solved by doing this:

table_window = None

def get_ClientsTable():
    global table_window
    if table_window is not None:
        dpg.delete_item(table_window)
        table_window = None

    with dpg.window(label="Clients List", width=gVars.window_width/1.5, height=gVars.window_height, no_collapse=True) as table_window:
        with dpg.menu_bar():
            dpg.add_menu_item(label="Add row")
        with dpg.table(header_row=True, tag="cTable"):
            dpg.add_table_column(label="Date", id="date")
            dpg.add_table_column(label="Number", id="pc")
            dpg.add_table_column(label="Price", id="price")
            dpg.add_table_column(label="Admin", id="admin")

[equidna]

It seems to exist some type of memory leak when the deleted item is a node editor. When repeatedly deleting and adding a node editor item the active allocations keep growing. Is this normal? Can anyone confirm this? Thanks.

[georgedimitriadis]

I have the same problem. I have a node editor and I call up also dpg.show_item_registry() to see what is goign on. When I create and delete a Node (and remove its alias) the registry keeps showing the Node so as I keep doing this the registry keeps growing. The Node though does disapear from the editor.
If I use the registry window's Delete button then the item gets deleted.