Why another template recipe?

Both iw.recipe.template and inquant.recipe.textfile claim to do the same thing. I have found them to be undocumented and too buggy for real world use, and neither are in a public repository where I could fix them. In addition this implementation leverages the buildout variable substitution code, making it a lot simpler.

Simple creation of a file out of a template

Lets create a minimal buildout.cfg file:

>>> write('buildout.cfg',
... '''
... [buildout]
... parts = template
... offline = true
...
... [template]
... recipe = collective.recipe.template
... input = template.in
... output = template
... ''')

We create a template file:

>>> write('template.in',
... '''#
... My template knows about buildout path:
...   ${buildout:directory}
... ''')

Now we can run buildout:

>>> print system(join('bin', 'buildout')),
Installing template.

The template was indeed created:

>>> cat('template')
#
My template knows about buildout path:
.../sample-buildout

The variable buildout:directory was also substituted by a path.

Creating a template in a variable path

Lets create a minimal buildout.cfg file. This time the output should happen in a variable path:

>>> write('buildout.cfg',
... '''
... [buildout]
... parts = template
... offline = true
...
... [template]
... recipe = collective.recipe.template
... input = template.in
... output = ${buildout:parts-directory}/template
... ''')

Now we can run buildout:

>>> print system(join('bin', 'buildout')),
Uninstalling template.
Installing template.

The template was indeed created:

>>> cat('parts', 'template')
#
My template knows about buildout path:
.../sample-buildout

Creating missing paths

If an output file should be created in a path that does not yet exist, then the missing items will be created for us:

>>> write('buildout.cfg',
... '''
... [buildout]
... parts = template
... offline = true
...
... [template]
... recipe = collective.recipe.template
... input = template.in
... output = ${buildout:parts-directory}/etc/template
... ''')

>>> print system(join('bin', 'buildout')),
Uninstalling template.
Installing template.

Also creation of several subdirectories is supported:

>>> write('buildout.cfg',
... '''
... [buildout]
... parts = template
... offline = true
...
... [template]
... recipe = collective.recipe.template
... input = template.in
... output = ${buildout:parts-directory}/foo/bar/template
... ''')

>>> print system(join('bin', 'buildout')),
Uninstalling template.
Installing template.

>>> cat('parts', 'foo', 'bar', 'template')
#
My template knows about buildout path:
.../sample-buildout

When changes happen to the output path, then the old path is removed on uninstall. Therefore the etc/ directory created above has vanished now:

>>> ls('parts')
d  foo

Substituting variables with options of other parts

When substituting variables in a template, dependencies on other buildout parts can occur. Buildout will resolve them by determining the values of those other parts' options first. To see this, we create a buildout involving a template that uses a variable computed by a part that would not otherwise be built:

>>> write('dummy.py',
... '''
... class Recipe(object):
...
...     def __init__(self, buildout, name, options):
...         options['foo'] = 'bar'
...
...     def install(self):
...         return ()
...
...     def update(self):
...         pass
... ''')

>>> write('setup.py',
... '''
... from setuptools import setup
...
... setup(name='dummyrecipe',
...       entry_points = {'zc.buildout': ['default = dummy:Recipe']})
... ''')

>>> write('buildout.cfg',
... '''
... [buildout]
... develop = .
... parts = template
... offline = true
...
... [template]
... recipe = collective.recipe.template
... input = template.in
... output = template
...
... [other]
... recipe = dummyrecipe
... ''')

>>> write('template.in',
... '''#
... My template knows about another buildout part:
... ${other:foo}
... ''')

>>> print system(join('bin', 'buildout')),
Develop: '/sample-buildout/.'
Uninstalling template.
Installing other.
Installing template.

>>> cat('template')
#
My template knows about another buildout part:
bar

1.4 (2009-07-29)

• Fixed the way variables in templates are substituted to allow buildout to determine dependencies on other parts and prepare those correctly. [tlotze]

1.3 - 2009-04-28

• Add support for output path creation. You can do:

  output = /path/to/target
  

  and intermediate path items will be created if they do not exist. [ulif]

• Add tests. [ulif]

1.2 - 2008-12-09

(By accident the 1.1 release was marked as 1.2. So in fact they are the same.)

1.1 - 2008-12-09

• Correct handling of multiple variables in a line. Bugreport and patch from Roman Susi. [wichert]

1.0 - 2008-10-16

• Copy the mode of the input file to the output file. This makes it possible to create executable scripts. [wichert]
• Add missing link in README. [wichert]

1.0rc2 - 2008-07-04

• Add a MANIFEST.in with instructions to include docs/, otherwise the package will not install. [wichert]

1.0rc1 - 2008-07-04

• Initial release. [wichert]