CODEWITHSUNDEEP
scons
Avi Chapman
Avi Chapman

Reputation: 339

Python SCons Action?

I've been searching the documentation for a long time and still can't figure this out.

In the SCons documentation, there is discussion about adding a PreAction or PostAction. In the examples, they call an example method:

foo = Program('foo.c')
AddPreAction(foo, 'pre_action')

This calls 'pre_action' before 'foo.c' is compiled and linked. However, there is no explanation about what format 'pre_action' must take.

I have discovered that there are several pre-built actions, such as 'Copy'. However, I cannot find the source of 'Copy' to reverse-engineer it and write my own.

Can anyone point me to a guide as to how to create my own Actions? I either need an interface for calling my own method such as 'pre_action' above, or a guide for writing an Action class.

Really, even just some example code that is actually complete enough to use would be helpful...

Upvotes: 1

Views: 888

Answers (1)

Mats Wichmann
Mats Wichmann

Reputation: 909

The manpage section Action Objects lists the types of things that can be passed to the Action factory function to create an action; that is also what you pass to AddPostAction and AddPreAction as the second argument - that is, either an Action already made by a previous call to Action, or something that can be converted into one like a command string, or a list of such, or a function with appropriate signature. Pre/Post will simply call the Action function with that argument. So in that section, where there's an example with a call to Action, you could just plug that argument into AddPreAction, or you could save the result of calling Action and give that as the argument to AddPreAction.

The amount of flexibility here makes it a little tricky to document concisely.

(btw the source to Copy is a function called copy_func but you probably don't want to use that form because it's a couple of extra levels of abstraction you won't need)

Upvotes: 1

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