what is notAlreadyHandled parameter in any component mean?

[Alice]

what is notAlreadyHandled parameter in any component mean?

is there any example? how it works?please~~~

[SteveJG]

Here is what MIT says Alice  http://appinventor.mit.edu/papers/s18-patton.pdf

notAlreadyHandled is a flag to control the application of generic vs. specific handlers for a component.  What does that mean?   Perhaps MIT will elaborate and provide a simple explanation.

Regards,

Steve

[ABG]

Here's an example ...

https://docs.google.com/document/d/1Ctf-tI-oRaoziGqb-V-h9ATAtVhCPvHY65EoVW-FpZA/edit#heading=h.qjerpbof05eg

ABG

[ABG]

Also see

https://github.com/AGetzler/eight_queens_generic

ABG

[Evan Patton]

Hi Alice,

When you have a mix of specific (e.g., when Button1.Click) and generic (e.g., when any Button.Click) handlers, we first run the handler for the specific component and then the handler for any component. The notAlreadyHandled is true if there wasn't already an event block for the specific component. If there was a specific event handler that already handled the event, then notAlreadyHandled is false. This allows you to mix specific and generic event handlers and decide in the generic event handler whether you want to apply behavior or not.

More details on the any component blocks and the algorithm to determine notAlreadyHandled here.

Regards,

Evan

[TimAI2]

@ Evan

Would be good if there was an example which included the notAlreadyHandled blocks in that very useful page ;)

[ABG]

I tidied up my explanation at https://docs.google.com/document/d/1Ctf-tI-oRaoziGqb-V-h9ATAtVhCPvHY65EoVW-FpZA/edit#heading=h.qjerpbof05eg

if you need sample code.

ABG