queuer | A simple Flask-based app for queued registration | Stream Processing library

even though Pusher and Popper don't know of elements, Stack does, and that's all that's important.

No. It’s not all that’s important as C++ is concerned, as you can clearly see — and with good reason. What you’re suggesting has numerous drawbacks and is thus not permitted. However, there are several ways to work around this limitation.

One way is to use virtual inheritance, and to define an abstract base class (called, e.g. Store) that provides access to the storage that both Pusher and Popper operate on via a virtual function that is implemented in Stack.

However, this approach also has numerous problems and is generally avoided in C++. A more idiomatic approach uses the Curiously recurring template pattern (CRTP).

Change your Pusher and Popper to class templates which take the Stack class as template argument:

The behavior you're observing is because of to the way 'value' events are different from 'childAdded' events.

In your first observer (using .value), you're simply requesting all the data from events/Oo75nbcDsUK7vPWGDbnL/queue/R5UwSxlH3vhH6SjTNMGfMoiaGae2 in a single snapshot. If any data under the location changes while that observer is still added, your observer will get invoked again with a snapshot of everything at that location.

In your second observer (using .childAdded), you're requesting that your observer be called once for each child at events/Oo75nbcDsUK7vPWGDbnL/queue. If you have two children there, your observer will be called once for each child. As new children are added at that location, your observer will get called again, once for each new one.

The observers are not interfering with each other. They're just doing different things.

Firebase Database can order/filter on properties that are on a known path under each child node of the location where you run the query. You're trying to filter on a dynamic path, which isn't possible.

You'll typically want to add an extra data structure to allow the lookup you want, e.g. a top-level list with the queue ids as keys, and then their event id as the value.

I noticed this in one of my apps. I like the look of passing in the method itself, but I also had to use the weak reference technique you mentioned.

This makes sense, I think, because method implementations are held on the class itself, and self is bound to that implementation when classes are instantiated. Therefore a method will always have a strong reference to self.

And in Swift, function parameters are strongly referenced. I don’t think there’s a way to pass any parameter using a weak reference.

Depending on which version of PHPixie you are using, there are different solutions to specify the table name for a model:

Assuming you already have a Person model, you can specify the table name using the $table field:

Solved it! I didn't set the initialListSize on my listview. initialListSize defaults to 10 and stops rerenders after that size has been reached.

This helped: React Native ListView doesn't rerender for large data