Add onBeforeFileAdded callback?

[whafrog]

I would think this would be generally useful, but for my specific case:

I need to be able to put input controls into a grid, so that a user can upload single files tied to specific types (model data) behind the scenes. If the user selects a file, changes their mind, and selects a second file, both files are added to the queue. I need to be able to update the queue to remove any previous selections associated with that model data.

I can do this with a filter, but it doesn't seem the right role for a filter.
I can do this using onAfterAddingFile, but the logic is more convoluted since I need to count items associated with model data, and make assumptions about queue order.

[ernie58]

+1

[nervgh]

I need to be able to update the queue to remove any previous selections associated with that model data.

See API

• uploader.removeFromQueue()
• uploader.clearQueue()
• item.remove()

[ernie58]

The issue was not about the functionality for managing the queue, it was about when you could do this in the flow. Now it has to be done in the filter, which feels hacky

[nervgh]

it was about when you could do this in the flow

Then you should explain what you mean. Also you can search async filters issue.

[ernie58]

It would be nice to have a callback executed when a user is attempting to add a file, e.g. onBeforeFileAdded. I only want one item in the queue, so now I have to do this in a filter function, which doesn't feel like the right place:

while(uploader.queue.length > 1){
    uploader.removeFromQueue(0);
}

The problem is not that it's much code, or it doesn't work, but it is not logic to put it in a filter function.
When there would be a callback onBeforeFileAdded, I could simply do uploader.clearQueue()

Does this make sense ?

[nervgh]

See queueLimit

[ernie58]

In my case I want the last added file. With queueLimit, one cannot add
another file, without removing this one.
I want to make the steps the user has to take as minimal as possible.

I don't see it as a bug, just an extra feature that could be useful in some
cases

[nervgh]

I don't see it as a bug, just an extra feature that could be useful in some

Thanks. I understood you 👍

[whafrog]

I did end up implementing a solution using onAfterAddingFile, because technically, yes, all the API calls are available. But having an onBeforeAddingFile method would be more elegant, and simpler.

The main issue is that by the time onAfterAddingFile is triggered, all the behind-the-scenes code has been run...the file is in the queue (and, one hopes, in the order it was inserted) and unnecessary data associations are made, data associations that might not be unravelled correctly. It would seem prudent to be able to run maintenance code before a file is actually added to the queue, without the danger of messing up data associations that might be critical or having to make assumptions about queue order.