allow to provide custom getValue() and getDelta() functions

I have a huge data set that I embed in html as json object that follows d3-flamegraph specification. I also add several custom fields to it, such as syscall count, vmfault count, etc. I would like to have an easy way to choose what subset of data to display in a flame graph, preferably without regenerating the whole data structure (e.g. now I’ll need to traverse the whole tree to place what I want into the value field).

Describe the solution you’d like Some way to provide custom implementations of getValue() and getDelta() functions. This also will allow to make data more compact. E.g., for comparison view, I can have A and B values in the data (since I want to show them in a tooltip anyway), so I don’t need to store delta and can compute it easily in getDelta() function.

[spiermar]

What is the use case for node.value other than node’s width?

Exactly when I need to know the node’s width.

[wonder-mice]

Check this out: https://github.com/spiermar/d3-flame-graph/pull/120

It has some differences visible from outside though:

• No transitionDuration / transitionEase functions. Must supply custom CSS class instead to control transitions. Don’t have setter for that yet though.
• Tooltip doesn’t have arrows because I didn’t have tome to replicate this part of behavior and I think it’s not super important