[Button] Change LoadingButton prop pending to loading

I’m very happy to see the new pre-release v5.0.0-alpha.1. I noticed something:

• The Autocomplete component has a prop called loading.
• The LoadingButton component has a prop called pending.

For convention, I think all components should use the word loading. Also it feels it makes sense after the component name

[oliviertassinari]

Looking at the semantic, we have:

• pending: “about to happen or waiting to happen” https://dictionary.cambridge.org/dictionary/english/pending
• loading: Present participle of the verb load: c) to copy or transfer (something, such as a program or data) into the memory of a digital device (such as a computer) especially from an external source (such as a disk drive or the Internet) https://www.merriam-webster.com/dictionary/load

The use of pending echos back to https://reactjs.org/docs/concurrent-mode-patterns.html#the-three-steps.

I don’t have any strong preference, I think that we can settle this with a vote, the end goal is to make it intuitive to developers.

• 👍 for loading
• 🎉 for pending

[ryancogswell]

@eps1lon Are you arguing for pending only for the prop name or do you also think the component should be called PendingButton? If you are fine with the component name of LoadingButton, why do you feel differently about the prop?

It will always tell if something else is pending. Sometimes this will indicate loading.

In what case is a transition pending when it isn’t because something (code or data) is loading?

It is a special case of a pending transition.

I disagree. I don’t feel like either is broader. “pending” focuses on the state of transition, “loading” refers to why the transition is pending. Why haven’t we transitioned yet? Because we’re still loading something. So the question becomes, is it more intuitive to refer to the transition state or is it more intuitive to refer to the activity that is the cause of the transition state. I would argue that developers will ask, “what is the property I need to set to show that something is still loading?” more readily than asking “what is the property I need to set to indicate that my transition is in a pending state?”

Reusing this terminology for transitions sets the UI up for failure.

In what way does using the term “loading” set the UI up for failure? If someone isn’t aware of the new capabilities provided by concurrent mode in React and how to use them, Material-UI using “pending” for this prop name isn’t going to make them more aware. And if a developer does understand the nuances of concurrent mode, Material-UI using “loading” for this prop name is not going to lead them astray.