Apex Collection - tracking changes/updates on cells

Question

I created an apex collections page which displays and allows user to update the array/matrix/cells.
I created a button to apply and save the changes; this process is working fine for update/insert as necessary.
I'm struggling on a couple of points:
1. If the user gets out of the page or do a refresh, I wanted to show an error or message that when a cell has been updated in the page, to display an error-like " that there are unsaved changes". And let them click on the update button I created. I read that there is the function called COLLECTION_HAS_CHANGED however, I'm not quite sure how to make it work with Dynamic Action.
Any guidance is greatly appreciated. Thanks.
2 Updating a cell value from not null to null is a bit of a challenge.
The question is: Is there a way to find if a cell's value is changed from not null to null during the time I'm performing update_member_attribute ?
(The update_member_attribute I found on the forum and I am using is handling it using IS NOT NULL -- I think this is good because it will avoid me getting a bunch of records inserted if the cells are indeed NULL (before and after).
below is the part of the code I'm referring to ...
FOR i IN 1.. APEX_APPLICATION.G_F02.COUNT LOOP
IF apex_application.g_f02 (i) IS NOT NULL THEN
APEX_COLLECTION.UPDATE_MEMBER_ATTRIBUTE (
p_collection_name => 'COLLECTION1',
p_seq => i,
p_attr_number => 2,
p_attr_value => apex_application.g_f02 (i));
END IF;
END LOOP;
I could removed the NOT NULL IF condition, but I only wanted to do the null update when there was a value previously.
Thanks.

Answer 1

user12941774 wrote:
I created an apex collections page which displays and allows user to update the array/matrix/cells.
I created a button to apply and save the changes; this process is working fine for update/insert as necessary.
I'm struggling on a couple of points:
1. If the user gets out of the page or do a refresh, I wanted to show an error or message that when a cell has been updated in the page, to display an error-like " that there are
unsaved changes". And let them click on the update button I created. I read that there is the function called COLLECTION_HAS_CHANGED however, I'm not quite sure how to make
it work with Dynamic Action.COLLECTION_HAS_CHANGED This will be useful if the data has changed on the server side, and you are talking about user navigating away without saving the changes that means the data is entered only on the client/browser side.
For handling that you can use this plugin http://apex-plugin.com/oracle-apex-plugins/dynamic-action-plugin/skillbuilders-save-before-exit_43.html
Any guidance is greatly appreciated. Thanks.
2 Updating a cell value from not null to null is a bit of a challenge. Why do you think its a challenge?
You will be updating a cell value based on the user entry, no matter if it is null or not null.
The question is: Is there a way to find if a cell's value is changed from not null to null during the time I'm performing update_member_attribute ?
(The update_member_attribute I found on the forum and I am using is handling it using IS NOT NULL -- I think this is good because it will avoid me getting a bunch of records inserted if the cells are indeed NULL (before and after).
below is the part of the code I'm referring to ...
FOR i IN 1.. APEX_APPLICATION.G_F02.COUNT LOOP
IF apex_application.g_f02 (i) IS NOT NULL THEN
APEX_COLLECTION.UPDATE_MEMBER_ATTRIBUTE (
p_collection_name => 'COLLECTION1',
p_seq => i,
p_attr_number => 2,
p_attr_value => apex_application.g_f02 (i));
END IF;
END LOOP;*Always include code between {noformat}{noformat} tags, it is more readable*