First cut at issue 35: single file templates

[talwrii]

Pull request for issue #35

I imagine people might have quite a lot of opinions about how this should be implemented. But I really want this feature, so I'll throw up a strawman for people to have opinions on.

The approach here is to add a _target setting to cookiecutter.json which gets rendered to a directory into which files get copied.

Demonstrating I've read the contributing file:

• Can someone add a please-help tag to this request I don't have the permissions?
• It is definitely possible to implement this outside of cookiecutter... but it's slightly perverse to have a separate utility for expanding a specific type of template.
• I've written tests and run them with tox they pass for py27 and py35. If someone can tell me how to easily install 7 versions of python that would be useful.

Some thorny issues that people might have opinions on:

• How file overwriting should work. I overwrite nothign unless the -f flag is given
• Are we actually happy with relative paths
• It's a bit perverse that you have to use a directory name like '{{cookiecutter.source}}' in the template which then gets ignored.

I've written some documentation but was unable to get make the documentation run, make servedocs hangs with

python -c "$BROWSER_PYSCRIPT" docs/_build/html/index.html
watchmedo shell-command -p '*.rst' -c 'make -C docs html' -R -D .

and no ports are listened on.

[codecov-io]

Current coverage is 100% (diff: 100%)

Merging #885 into master will not change coverage

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Powered by Codecov. Last update a111ed8...1cdb9d7

[talwrii]

Fixing coverage at the moment.

[talwrii]

Okay that should fix the coverage.

Cue argument about "#pragma: no cover" in switch statement...

[talwrii]

Okay, I've actually rendered the documentation and looked at it now.

At this point I'm tempted to do a rebase but imagine this might annoy people...

[talwrii]

Some thoughts on actually using this in anger:

This feature allows you for have generated code co-existing with code that people have written, this opens up a number of issues:

• We have to be very careful about some of the deletion logic here ("whoops I deleted your entire repository by mistake, sorry"). I started thinking things like "you should only overwrite this if I haven't changed it or marked it as modified)"
• I found myself wanting to overwrite some files but not others. A specific use case: I created a setup.py (which I wanted to overwrite), but I also created a module in a package directory which I didn't.
• This creates various complexities, is this (stable) tool actually the best place to deal with them?

[talwrii]

Another potential-complexity / creeping-feature from using this in practice:

• When using different templates in the same project I kept on wanting to have a shared context / replay between the different templates. The use case goes like this:

"Right, lets set up the base project with this cookie cutter"
"Let's add testing like this - hmm I need to re-enter all these details agauin"
"Let's add testing with nose rather py.test - hmm I need add the details again"
"Let's add a license as well"

I don't know what I think about the argument that these should all be in the same template...

[sergray]

@talwrii,

1. overwriting only if explicitly requested with a flag should be good enough
2. not sure about {{cookiecutter.source}}, imagine someone would like to have such variable. What about using something like {{cookicutter.__tree__}}?

[talwrii]

Thanks for the feedback @sergray

overwriting only if explicitly requested with a flag should be good enough

This is the current behaviour.

not sure about {{cookiecutter.source}}

I have no strong opinions about this. The directory can be called anything: {{cookiecutter.source}}, {{cookiecutter.foo}} or {{cookiecutter.__tree__}} all work fine. Using the value for something else has no effect. This implementation kind of naturally falls out of how the code is currently structured. I can throw in an assertion about the value though if constraining this prevents confusion.

[turing4ever]

It seems all checks have passed but the code hasn’t been merged?

[mmynsted]

Is anybody working on resolving the conflicts?

[kurtmckee]

I'm closing this PR due to its age.