Mercurial > public > mercurial-scm > hg
comparison mercurial/extensions.py @ 11402:367ce8514da0
extensions: recommend against using wrapfunction for repo methods
Instead, all extensions should use the "dynamic subclass" trick:
subclass repo.__class__ and then replace repo.__class__ with your new
subclass. This avoids conflicts that happen when one extension uses
wrapfunction and another uses subclassing to extend the same method of
localrepository.
| author | Greg Ward <greg-hg@gerg.ca> |
|---|---|
| date | Tue, 15 Jun 2010 13:04:22 -0400 |
| parents | de1e7099d100 |
| children | bbdf1fb1d3e3 |
comparison
equal
deleted
inserted
replaced
| 11401:3bc892f740d6 | 11402:367ce8514da0 |
|---|---|
| 122 newentry[0] = wrap | 122 newentry[0] = wrap |
| 123 table[key] = tuple(newentry) | 123 table[key] = tuple(newentry) |
| 124 return entry | 124 return entry |
| 125 | 125 |
| 126 def wrapfunction(container, funcname, wrapper): | 126 def wrapfunction(container, funcname, wrapper): |
| 127 '''Wrap the function named funcname in container | |
| 128 | |
| 129 It is replacing with your wrapper. The container is typically a | |
| 130 module, class, or instance. | |
| 131 | |
| 132 The wrapper will be called like | |
| 133 | |
| 134 wrapper(orig, *args, **kwargs) | |
| 135 | |
| 136 where orig is the original (wrapped) function, and *args, **kwargs | |
| 137 are the arguments passed to it. | |
| 138 | |
| 139 Wrapping methods of the repository object is not recommended since | |
| 140 it conflicts with extensions that extend the repository by | |
| 141 subclassing. All extensions that need to extend methods of | |
| 142 localrepository should use this subclassing trick: namely, | |
| 143 reposetup() should look like | |
| 144 | |
| 145 def reposetup(ui, repo): | |
| 146 class myrepo(repo.__class__): | |
| 147 def whatever(self, *args, **kwargs): | |
| 148 [...extension stuff...] | |
| 149 super(myrepo, self).whatever(*args, **kwargs) | |
| 150 [...extension stuff...] | |
| 151 | |
| 152 repo.__class__ = myrepo | |
| 153 | |
| 154 In general, combining wrapfunction() with subclassing does not | |
| 155 work. Since you cannot control what other extensions are loaded by | |
| 156 your end users, you should play nicely with others by using the | |
| 157 subclass trick. | |
| 158 ''' | |
| 127 def wrap(*args, **kwargs): | 159 def wrap(*args, **kwargs): |
| 128 return wrapper(origfn, *args, **kwargs) | 160 return wrapper(origfn, *args, **kwargs) |
| 129 | 161 |
| 130 origfn = getattr(container, funcname) | 162 origfn = getattr(container, funcname) |
| 131 setattr(container, funcname, wrap) | 163 setattr(container, funcname, wrap) |