rev |
line source |
bos@34
|
1 \chapter{Handling repository events with hooks}
|
bos@34
|
2 \label{chap:hook}
|
bos@34
|
3
|
bos@34
|
4 Mercurial offers a powerful mechanism to let you perform automated
|
bos@34
|
5 actions in response to events that occur in a repository. In some
|
bos@34
|
6 cases, you can even control Mercurial's response to those events.
|
bos@34
|
7
|
bos@34
|
8 The name Mercurial uses for one of these actions is a \emph{hook}.
|
bos@34
|
9 Hooks are called ``triggers'' in some revision control systems, but
|
bos@34
|
10 the two names refer to the same idea.
|
bos@34
|
11
|
bos@38
|
12 \section{An overview of hooks in Mercurial}
|
bos@38
|
13
|
bos@38
|
14 Here is a brief list of the hooks that Mercurial supports. For each
|
bos@38
|
15 hook, we indicate when it is run, and a few examples of common tasks
|
bos@38
|
16 you can use it for. We will revisit each of these hooks in more
|
bos@38
|
17 detail later.
|
bos@38
|
18 \begin{itemize}
|
bos@38
|
19 \item[\small\hook{changegroup}] This is run after a group of
|
bos@38
|
20 changesets has been brought into the repository from elsewhere. In
|
bos@38
|
21 other words, it is run after a \hgcmd{pull} or \hgcmd{push} into a
|
bos@38
|
22 repository, but not after a \hgcmd{commit}. You can use this for
|
bos@38
|
23 performing an action once for the entire group of newly arrived
|
bos@38
|
24 changesets. For example, you could use this hook to send out email
|
bos@38
|
25 notifications, or kick off an automated build or test.
|
bos@38
|
26 \item[\small\hook{commit}] This is run after a new changeset has been
|
bos@38
|
27 created in the local repository, typically using the \hgcmd{commit}
|
bos@38
|
28 command.
|
bos@38
|
29 \item[\small\hook{incoming}] This is run once for each new changeset
|
bos@38
|
30 that is brought into the repository from elsewhere. Notice the
|
bos@38
|
31 difference from \hook{changegroup}, which is run once per
|
bos@38
|
32 \emph{group} of changesets brought in. You can use this for the
|
bos@38
|
33 same purposes as the \hook{changegroup} hook; it's simply more
|
bos@38
|
34 convenient sometimes to run a hook once per group of changesets,
|
bos@38
|
35 while othher times it's handier once per changeset.
|
bos@38
|
36 \item[\small\hook{outgoing}] This is run after a group of changesets
|
bos@38
|
37 has been transmitted from this repository to another. You can use
|
bos@38
|
38 this, for example, to notify subscribers every time changes are
|
bos@38
|
39 cloned or pulled from the repository.
|
bos@38
|
40 \item[\small\hook{prechangegroup}] This is run before starting to
|
bos@38
|
41 bring a group of changesets into the repository. It cannot see the
|
bos@38
|
42 actual changesets, because they have not yet been transmitted. If
|
bos@38
|
43 it fails, the changesets will not be transmitted. You can use this
|
bos@38
|
44 hook to ``lock down'' a repository against incoming changes.
|
bos@38
|
45 \item[\small\hook{precommit}] This is run before starting a commit.
|
bos@38
|
46 It cannot tell what files are included in the commit, or any other
|
bos@38
|
47 information about the commit. If it fails, the commit will not be
|
bos@38
|
48 allowed to start. You can use this to perform a build and require
|
bos@38
|
49 it to complete successfully before a commit can proceed, or
|
bos@38
|
50 automatically enforce a requirement that modified files pass your
|
bos@38
|
51 coding style guidelines.
|
bos@38
|
52 \item[\small\hook{preoutgoing}] This is run before starting to
|
bos@38
|
53 transmit a group of changesets from this repository. You can use
|
bos@38
|
54 this to lock a repository against clones or pulls from remote
|
bos@38
|
55 clients.
|
bos@38
|
56 \item[\small\hook{pretag}] This is run before creating a tag. If it
|
bos@38
|
57 fails, the tag will not be created. You can use this to enforce a
|
bos@38
|
58 uniform tag naming convention.
|
bos@38
|
59 \item[\small\hook{pretxnchangegroup}] This is run after a group of
|
bos@38
|
60 changesets has been brought into the local repository from another,
|
bos@38
|
61 but before the transaction completes that will make the changes
|
bos@38
|
62 permanent in the repository. If it fails, the transaction will be
|
bos@38
|
63 rolled back and the changes will disappear from the local
|
bos@38
|
64 repository. You can use this to automatically check newly arrived
|
bos@38
|
65 changes and, for example, roll them back if the group as a whole
|
bos@38
|
66 does not build or pass your test suite.
|
bos@38
|
67 \item[\small\hook{pretxncommit}] This is run after a new changeset has
|
bos@38
|
68 been created in the local repository, but before the transaction
|
bos@38
|
69 completes that will make it permanent. Unlike the \hook{precommit}
|
bos@38
|
70 hook, this hook can see which changes are present in the changeset,
|
bos@38
|
71 and it can also see all other changeset metadata, such as the commit
|
bos@38
|
72 message. You can use this to require that a commit message follows
|
bos@38
|
73 your local conventions, or that a changeset builds cleanly.
|
bos@38
|
74 \item[\small\hook{preupdate}] This is run before starting an update or
|
bos@38
|
75 merge of the working directory.
|
bos@38
|
76 \item[\small\hook{tag}] This is run after a tag is created.
|
bos@38
|
77 \item[\small\hook{update}] This is run after an update or merge of the
|
bos@38
|
78 working directory has finished.
|
bos@38
|
79 \end{itemize}
|
bos@38
|
80 Each of the hooks with a ``\texttt{pre}'' prefix has the ability to
|
bos@38
|
81 \emph{control} an activity. If the hook succeeds, the activity may
|
bos@38
|
82 proceed; if it fails, the activity is either not permitted or undone,
|
bos@38
|
83 depending on the hook.
|
bos@38
|
84
|
bos@38
|
85 \section{Hooks and security}
|
bos@38
|
86
|
bos@38
|
87 \subsection{Hooks are run with your privileges}
|
bos@38
|
88
|
bos@38
|
89 When you run a Mercurial command in a repository, and the command
|
bos@38
|
90 causes a hook to run, that hook runs on your system, under your user
|
bos@38
|
91 account, with your privilege level. Since hooks are arbitrary pieces
|
bos@38
|
92 of executable code, you should treat them with an appropriate level of
|
bos@38
|
93 suspicion. Do not install a hook unless you are confident that you
|
bos@38
|
94 know who created it and what it does.
|
bos@38
|
95
|
bos@38
|
96 In some cases, you may be exposed to hooks that you did not install
|
bos@38
|
97 yourself. If you work with Mercurial on an unfamiliar system,
|
bos@38
|
98 Mercurial will run hooks defined in that system's global \hgrc\ file.
|
bos@38
|
99
|
bos@38
|
100 If you are working with a repository owned by another user, Mercurial
|
bos@38
|
101 will run hooks defined in that repository. For example, if you
|
bos@38
|
102 \hgcmd{pull} from that repository, and its \sfilename{.hg/hgrc}
|
bos@38
|
103 defines a local \hook{outgoing} hook, that hook will run under your
|
bos@38
|
104 user account, even though you don't own that repository.
|
bos@38
|
105
|
bos@38
|
106 \begin{note}
|
bos@38
|
107 This only applies if you are pulling from a repository on a local or
|
bos@38
|
108 network filesystem. If you're pulling over http or ssh, any
|
bos@38
|
109 \hook{outgoing} hook will run under the account of the server
|
bos@38
|
110 process, on the server.
|
bos@38
|
111 \end{note}
|
bos@38
|
112
|
bos@38
|
113 XXX To see what hooks are defined in a repository, use the
|
bos@38
|
114 \hgcmdargs{config}{hooks} command. If you are working in one
|
bos@38
|
115 repository, but talking to another that you do not own (e.g.~using
|
bos@38
|
116 \hgcmd{pull} or \hgcmd{incoming}), remember that it is the other
|
bos@38
|
117 repository's hooks you should be checking, not your own.
|
bos@38
|
118
|
bos@38
|
119 \subsection{Hooks do not propagate}
|
bos@38
|
120
|
bos@38
|
121 In Mercurial, hooks are not revision controlled, and do not propagate
|
bos@38
|
122 when you clone, or pull from, a repository. The reason for this is
|
bos@38
|
123 simple: a hook is a completely arbitrary piece of executable code. It
|
bos@38
|
124 runs under your user identity, with your privilege level, on your
|
bos@38
|
125 machine.
|
bos@38
|
126
|
bos@38
|
127 It would be extremely reckless for any distributed revision control
|
bos@38
|
128 system to implement revision-controlled hooks, as this would offer an
|
bos@38
|
129 easily exploitable way to subvert the accounts of users of the
|
bos@38
|
130 revision control system.
|
bos@38
|
131
|
bos@38
|
132 Since Mercurial does not propagate hooks, if you are collaborating
|
bos@38
|
133 with other people on a common project, you should not assume that they
|
bos@38
|
134 are using the same Mercurial hooks as you are, or that theirs are
|
bos@38
|
135 correctly configured. You should document the hooks you expect people
|
bos@38
|
136 to use.
|
bos@38
|
137
|
bos@38
|
138 In a corporate intranet, this is somewhat easier to control, as you
|
bos@38
|
139 can for example provide a ``standard'' installation of Mercurial on an
|
bos@38
|
140 NFS filesystem, and use a site-wide \hgrc\ file to define hooks that
|
bos@38
|
141 all users will see. However, this too has its limits; see below.
|
bos@38
|
142
|
bos@38
|
143 \subsection{Hooks can be overridden}
|
bos@38
|
144
|
bos@38
|
145 Mercurial allows you to override a hook definition by redefining the
|
bos@38
|
146 hook. You can disable it by setting its value to the empty string, or
|
bos@38
|
147 change its behaviour as you wish.
|
bos@38
|
148
|
bos@38
|
149 If you deploy a system-~or site-wide \hgrc\ file that defines some
|
bos@38
|
150 hooks, you should thus understand that your users can disable or
|
bos@38
|
151 override those hooks.
|
bos@38
|
152
|
bos@38
|
153 \subsection{Ensuring that critical hooks are run}
|
bos@38
|
154
|
bos@38
|
155 Sometimes you may want to enforce a policy that you do not want others
|
bos@38
|
156 to be able to work around. For example, you may have a requirement
|
bos@38
|
157 that every changeset must pass a rigorous set of tests. Defining this
|
bos@38
|
158 requirement via a hook in a site-wide \hgrc\ won't work for remote
|
bos@38
|
159 users on laptops, and of course local users can subvert it at will by
|
bos@38
|
160 overriding the hook.
|
bos@38
|
161
|
bos@38
|
162 Instead, you can set up your policies for use of Mercurial so that
|
bos@38
|
163 people are expected to propagate changes through a well-known
|
bos@38
|
164 ``canonical'' server that you have locked down and configured
|
bos@38
|
165 appropriately.
|
bos@38
|
166
|
bos@38
|
167 One way to do this is via a combination of social engineering and
|
bos@38
|
168 technology. Set up a restricted-access account; users can push
|
bos@38
|
169 changes over the network to repositories managed by this account, but
|
bos@38
|
170 they cannot log into the account and run normal shell commands. In
|
bos@38
|
171 this scenario, a user can commit a changeset that contains any old
|
bos@38
|
172 garbage they want.
|
bos@38
|
173
|
bos@38
|
174 When someone pushes a changeset to the server that everyone pulls
|
bos@38
|
175 from, the server will test the changeset before it accepts it as
|
bos@38
|
176 permanent, and reject it if it fails to pass the test suite. If
|
bos@38
|
177 people only pull changes from this filtering server, it will serve to
|
bos@38
|
178 ensure that all changes that people pull have been automatically
|
bos@38
|
179 vetted.
|
bos@38
|
180
|
bos@34
|
181 \section{A short tutorial on using hooks}
|
bos@34
|
182 \label{sec:hook:simple}
|
bos@34
|
183
|
bos@34
|
184 It is easy to write a Mercurial hook. Let's start with a hook that
|
bos@34
|
185 runs when you finish a \hgcmd{commit}, and simply prints the hash of
|
bos@34
|
186 the changeset you just created. The hook is called \hook{commit}.
|
bos@34
|
187
|
bos@34
|
188 \begin{figure}[ht]
|
bos@34
|
189 \interaction{hook.simple.init}
|
bos@34
|
190 \caption{A simple hook that runs when a changeset is committed}
|
bos@34
|
191 \label{ex:hook:init}
|
bos@34
|
192 \end{figure}
|
bos@34
|
193
|
bos@34
|
194 All hooks follow the pattern in example~\ref{ex:hook:init}. You add
|
bos@34
|
195 an entry to the \rcsection{hooks} section of your \hgrc\. On the left
|
bos@34
|
196 is the name of the event to trigger on; on the right is the action to
|
bos@34
|
197 take. As you can see, you can run an arbitrary shell command in a
|
bos@34
|
198 hook. Mercurial passes extra information to the hook using
|
bos@34
|
199 environment variables (look for \envar{HG\_NODE} in the example).
|
bos@34
|
200
|
bos@34
|
201 \subsection{Performing multiple actions per event}
|
bos@34
|
202
|
bos@34
|
203 Quite often, you will want to define more than one hook for a
|
bos@34
|
204 particular kind of event, as shown in example~\ref{ex:hook:ext}.
|
bos@34
|
205 Mercurial lets you do this by adding an \emph{extension} to the end of
|
bos@34
|
206 a hook's name. You extend a hook's name by giving the name of the
|
bos@34
|
207 hook, followed by a full stop (the ``\texttt{.}'' character), followed
|
bos@34
|
208 by some more text of your choosing. For example, Mercurial will run
|
bos@34
|
209 both \texttt{commit.foo} and \texttt{commit.bar} when the
|
bos@34
|
210 \texttt{commit} event occurs.
|
bos@34
|
211
|
bos@34
|
212 \begin{figure}[ht]
|
bos@34
|
213 \interaction{hook.simple.ext}
|
bos@34
|
214 \caption{Defining a second \hook{commit} hook}
|
bos@34
|
215 \label{ex:hook:ext}
|
bos@34
|
216 \end{figure}
|
bos@34
|
217
|
bos@34
|
218 To give a well-defined order of execution when there are multiple
|
bos@34
|
219 hooks defined for an event, Mercurial sorts hooks by extension, and
|
bos@34
|
220 executes the hook commands in this sorted order. In the above
|
bos@34
|
221 example, it will execute \texttt{commit.bar} before
|
bos@34
|
222 \texttt{commit.foo}, and \texttt{commit} before both.
|
bos@34
|
223
|
bos@34
|
224 It is a good idea to use a somewhat descriptive extension when you
|
bos@34
|
225 define a new hook. This will help you to remember what the hook was
|
bos@34
|
226 for. If the hook fails, you'll get an error message that contains the
|
bos@34
|
227 hook name and extension, so using a descriptive extension could give
|
bos@34
|
228 you an immediate hint as to why the hook failed (see
|
bos@34
|
229 section~\ref{sec:hook:perm} for an example).
|
bos@34
|
230
|
bos@34
|
231 \subsection{Controlling whether an activity can proceed}
|
bos@34
|
232 \label{sec:hook:perm}
|
bos@34
|
233
|
bos@34
|
234 In our earlier examples, we used the \hook{commit} hook, which is
|
bos@34
|
235 run after a commit has completed. This is one of several Mercurial
|
bos@34
|
236 hooks that run after an activity finishes. Such hooks have no way of
|
bos@34
|
237 influencing the activity itself.
|
bos@34
|
238
|
bos@34
|
239 Mercurial defines a number of events that occur before an activity
|
bos@34
|
240 starts; or after it starts, but before it finishes. Hooks that
|
bos@34
|
241 trigger on these events have the added ability to choose whether the
|
bos@34
|
242 activity can continue, or will abort.
|
bos@34
|
243
|
bos@34
|
244 The \hook{pretxncommit} hook runs after a commit has all but
|
bos@34
|
245 completed. In other words, the metadata representing the changeset
|
bos@34
|
246 has been written out to disk, but the transaction has not yet been
|
bos@34
|
247 allowed to complete. The \hook{pretxncommit} hook has the ability to
|
bos@34
|
248 decide whether the transaction can complete, or must be rolled back.
|
bos@34
|
249
|
bos@34
|
250 If the \hook{pretxncommit} hook exits with a status code of zero, the
|
bos@34
|
251 transaction is allowed to complete; the commit finishes; and the
|
bos@34
|
252 \hook{commit} hook is run. If the \hook{pretxncommit} hook exits with
|
bos@34
|
253 a non-zero status code, the transaction is rolled back; the metadata
|
bos@34
|
254 representing the changeset is erased; and the \hook{commit} hook is
|
bos@34
|
255 not run.
|
bos@34
|
256
|
bos@34
|
257 \begin{figure}[ht]
|
bos@34
|
258 \interaction{hook.simple.pretxncommit}
|
bos@34
|
259 \caption{Using the \hook{pretxncommit} hook to control commits}
|
bos@34
|
260 \label{ex:hook:pretxncommit}
|
bos@34
|
261 \end{figure}
|
bos@34
|
262
|
bos@34
|
263 The hook in example~\ref{ex:hook:pretxncommit} checks that a commit
|
bos@34
|
264 comment contains a bug ID. If it does, the commit can complete. If
|
bos@34
|
265 not, the commit is rolled back.
|
bos@34
|
266
|
bos@37
|
267 \section{Writing your own hooks}
|
bos@37
|
268
|
bos@37
|
269 When you are writing a hook, you might find it useful to run Mercurial
|
bos@37
|
270 either with the \hggopt{-v} option, or the \rcitem{ui}{verbose} config
|
bos@37
|
271 item set to ``true''. When you do so, Mercurial will print a message
|
bos@37
|
272 before it calls each hook.
|
bos@37
|
273
|
bos@37
|
274 \subsection{Choosing how your hook should run}
|
bos@37
|
275 \label{sec:hook:lang}
|
bos@34
|
276
|
bos@34
|
277 You can write a hook either as a normal program---typically a shell
|
bos@37
|
278 script---or as a Python function that is executed within the Mercurial
|
bos@34
|
279 process.
|
bos@34
|
280
|
bos@34
|
281 Writing a hook as an external program has the advantage that it
|
bos@34
|
282 requires no knowledge of Mercurial's internals. You can call normal
|
bos@34
|
283 Mercurial commands to get any added information you need. The
|
bos@34
|
284 trade-off is that external hooks are slower than in-process hooks.
|
bos@34
|
285
|
bos@34
|
286 An in-process Python hook has complete access to the Mercurial API,
|
bos@34
|
287 and does not ``shell out'' to another process, so it is inherently
|
bos@34
|
288 faster than an external hook. It is also easier to obtain much of the
|
bos@34
|
289 information that a hook requires by using the Mercurial API than by
|
bos@34
|
290 running Mercurial commands.
|
bos@34
|
291
|
bos@34
|
292 If you are comfortable with Python, or require high performance,
|
bos@34
|
293 writing your hooks in Python may be a good choice. However, when you
|
bos@34
|
294 have a straightforward hook to write and you don't need to care about
|
bos@34
|
295 performance (probably the majority of hooks), a shell script is
|
bos@34
|
296 perfectly fine.
|
bos@34
|
297
|
bos@37
|
298 \subsection{Hook parameters}
|
bos@34
|
299 \label{sec:hook:param}
|
bos@34
|
300
|
bos@34
|
301 Mercurial calls each hook with a set of well-defined parameters. In
|
bos@34
|
302 Python, a parameter is passed as a keyword argument to your hook
|
bos@34
|
303 function. For an external program, a parameter is passed as an
|
bos@34
|
304 environment variable.
|
bos@34
|
305
|
bos@34
|
306 Whether your hook is written in Python or as a shell script, the
|
bos@37
|
307 hook-specific parameter names and values will be the same. A boolean
|
bos@37
|
308 parameter will be represented as a boolean value in Python, but as the
|
bos@37
|
309 number 1 (for ``true'') or 0 (for ``false'') as an environment
|
bos@37
|
310 variable for an external hook. If a hook parameter is named
|
bos@37
|
311 \texttt{foo}, the keyword argument for a Python hook will also be
|
bos@37
|
312 named \texttt{foo} Python, while the environment variable for an
|
bos@37
|
313 external hook will be named \texttt{HG\_FOO}.
|
bos@37
|
314
|
bos@37
|
315 \subsection{Hook return values and activity control}
|
bos@37
|
316
|
bos@37
|
317 A hook that executes successfully must exit with a status of zero if
|
bos@37
|
318 external, or return boolean ``false'' if in-process. Failure is
|
bos@37
|
319 indicated with a non-zero exit status from an external hook, or an
|
bos@37
|
320 in-process hook returning boolean ``true''. If an in-process hook
|
bos@37
|
321 raises an exception, the hook is considered to have failed.
|
bos@37
|
322
|
bos@37
|
323 For a hook that controls whether an activity can proceed, zero/false
|
bos@37
|
324 means ``allow'', while non-zero/true/exception means ``deny''.
|
bos@37
|
325
|
bos@37
|
326 \subsection{Writing an external hook}
|
bos@37
|
327
|
bos@37
|
328 When you define an external hook in your \hgrc\ and the hook is run,
|
bos@37
|
329 its value is passed to your shell, which interprets it. This means
|
bos@37
|
330 that you can use normal shell constructs in the body of the hook.
|
bos@37
|
331
|
bos@37
|
332 An executable hook is always run with its current directory set to a
|
bos@37
|
333 repository's root directory.
|
bos@37
|
334
|
bos@37
|
335 Each hook parameter is passed in as an environment variable; the name
|
bos@37
|
336 is upper-cased, and prefixed with the string ``\texttt{HG\_}''.
|
bos@37
|
337
|
bos@37
|
338 With the exception of hook parameters, Mercurial does not set or
|
bos@37
|
339 modify any environment variables when running a hook. This is useful
|
bos@37
|
340 to remember if you are writing a site-wide hook that may be run by a
|
bos@37
|
341 number of different users with differing environment variables set.
|
bos@37
|
342 In multi-user situations, you should not rely on environment variables
|
bos@37
|
343 being set to the values you have in your environment when testing the
|
bos@37
|
344 hook.
|
bos@37
|
345
|
bos@37
|
346 \subsection{Telling Mercurial to use an in-process hook}
|
bos@37
|
347
|
bos@37
|
348 The \hgrc\ syntax for defining an in-process hook is slightly
|
bos@37
|
349 different than for an executable hook. The value of the hook must
|
bos@37
|
350 start with the text ``\texttt{python:}'', and continue with the
|
bos@37
|
351 fully-qualified name of a callable object to use as the hook's value.
|
bos@37
|
352
|
bos@37
|
353 The module in which a hook lives is automatically imported when a hook
|
bos@37
|
354 is run. So long as you have the module name and \envar{PYTHONPATH}
|
bos@37
|
355 right, it should ``just work''.
|
bos@37
|
356
|
bos@37
|
357 The following \hgrc\ example snippet illustrates the syntax and
|
bos@37
|
358 meaning of the notions we just described.
|
bos@37
|
359 \begin{codesample2}
|
bos@37
|
360 [hooks]
|
bos@37
|
361 commit.example = python:mymodule.submodule.myhook
|
bos@37
|
362 \end{codesample2}
|
bos@37
|
363 When Mercurial runs the \texttt{commit.example} hook, it imports
|
bos@37
|
364 \texttt{mymodule.submodule}, looks for the callable object named
|
bos@37
|
365 \texttt{myhook}, and calls it.
|
bos@37
|
366
|
bos@37
|
367 \subsection{Writing an in-process hook}
|
bos@37
|
368
|
bos@37
|
369 The simplest in-process hook does nothing, but illustrates the basic
|
bos@37
|
370 shape of the hook API:
|
bos@37
|
371 \begin{codesample2}
|
bos@37
|
372 def myhook(ui, repo, **kwargs):
|
bos@37
|
373 pass
|
bos@37
|
374 \end{codesample2}
|
bos@37
|
375 The first argument to a Python hook is always a
|
bos@37
|
376 \pymodclass{mercurial.ui}{ui} object. The second is a repository object;
|
bos@37
|
377 at the moment, it is always an instance of
|
bos@37
|
378 \pymodclass{mercurial.localrepo}{localrepository}. Following these two
|
bos@37
|
379 arguments are other keyword arguments. Which ones are passed in
|
bos@37
|
380 depends on the hook being called, but a hook can ignore arguments it
|
bos@37
|
381 doesn't care about by dropping them into a keyword argument dict, as
|
bos@37
|
382 with \texttt{**kwargs} above.
|
bos@34
|
383
|
bos@39
|
384 \section{Hook reference}
|
bos@39
|
385
|
bos@39
|
386
|
bos@39
|
387 \subsection{In-process hook execution}
|
bos@39
|
388
|
bos@39
|
389 An in-process hook is called with arguments of the following form:
|
bos@39
|
390 \begin{codesample2}
|
bos@39
|
391 def myhook(ui, repo, **kwargs):
|
bos@39
|
392 pass
|
bos@39
|
393 \end{codesample2}
|
bos@39
|
394 The \texttt{ui} parameter is a \pymodclass{mercurial.ui}{ui} object.
|
bos@39
|
395 The \texttt{repo} parameter is a
|
bos@39
|
396 \pymodclass{mercurial.localrepo}{localrepository} object. The
|
bos@39
|
397 names and values of the \texttt{**kwargs} parameters depend on the
|
bos@39
|
398 hook being invoked, with the following common features:
|
bos@39
|
399 \begin{itemize}
|
bos@39
|
400 \item If a parameter is named \texttt{node} or
|
bos@39
|
401 \texttt{parent\emph{N}}, it will contain a hexadecimal changeset ID.
|
bos@39
|
402 The empty string is used to represent ``null changeset ID'' instead
|
bos@39
|
403 of a string of zeroes.
|
bos@39
|
404 \item Boolean-valued parameters are represented as Python
|
bos@39
|
405 \texttt{bool} objects.
|
bos@39
|
406 \end{itemize}
|
bos@39
|
407
|
bos@39
|
408 An in-process hook is called without a change to the process's working
|
bos@39
|
409 directory (unlike external hooks, which are run in the root of the
|
bos@39
|
410 repository). It must not change the process's working directory. If
|
bos@39
|
411 it were to do so, it would probably cause calls to the Mercurial API,
|
bos@39
|
412 or operations after the hook finishes, to fail.
|
bos@39
|
413
|
bos@39
|
414 If a hook returns a boolean ``false'' value, it is considered to
|
bos@39
|
415 have succeeded. If it returns a boolean ``true'' value or raises an
|
bos@39
|
416 exception, it is considered to have failed.
|
bos@39
|
417
|
bos@39
|
418 \subsection{External hook execution}
|
bos@39
|
419
|
bos@39
|
420 An external hook is passed to the user's shell for execution, so
|
bos@39
|
421 features of that shell, such as variable substitution and command
|
bos@39
|
422 redirection, are available. The hook is run in the root directory of
|
bos@39
|
423 the repository.
|
bos@39
|
424
|
bos@39
|
425 Hook parameters are passed to the hook as environment variables. Each
|
bos@39
|
426 environment variable's name is converted in upper case and prefixed
|
bos@39
|
427 with the string ``\texttt{HG\_}''. For example, if the name of a
|
bos@39
|
428 parameter is ``\texttt{node}'', the name of the environment variable
|
bos@39
|
429 representing that parameter will be ``\texttt{HG\_NODE}''.
|
bos@39
|
430
|
bos@39
|
431 A boolean parameter is represented as the string ``\texttt{1}'' for
|
bos@39
|
432 ``true'', ``\texttt{0}'' for ``false''. If an environment variable is
|
bos@39
|
433 named \envar{HG\_NODE}, \envar{HG\_PARENT1} or \envar{HG\_PARENT2}, it
|
bos@39
|
434 contains a changeset ID represented as a hexadecimal string. The
|
bos@39
|
435 empty string is used to represent ``null changeset ID'' instead of a
|
bos@39
|
436 string of zeroes.
|
bos@39
|
437
|
bos@39
|
438 If a hook exits with a status of zero, it is considered to have
|
bos@39
|
439 succeeded. If it exits with a non-zero status, it is considered to
|
bos@39
|
440 have failed.
|
bos@39
|
441
|
bos@39
|
442 \subsection{The \hook{changegroup} hook}
|
bos@39
|
443 \label{sec:hook:changegroup}
|
bos@39
|
444
|
bos@40
|
445 This hook is run after a group of pre-existing changesets has been
|
bos@40
|
446 added to the repository, for example via a \hgcmd{pull} or
|
bos@40
|
447 \hgcmd{unbundle}. This hook is run once per operation that added one
|
bos@40
|
448 or more changesets.
|
bos@40
|
449
|
bos@40
|
450 Parameters to this hook:
|
bos@40
|
451 \begin{itemize}
|
bos@40
|
452 \item[\texttt{node}] A changeset ID. The changeset ID of the first
|
bos@40
|
453 changeset in the group that was added. All changesets between this
|
bos@40
|
454 and \index{tags!\texttt{tip}}\texttt{tip}, inclusive, were added by
|
bos@40
|
455 a single \hgcmd{pull}, \hgcmd{push} or \hgcmd{unbundle}.
|
bos@40
|
456 \end{itemize}
|
bos@40
|
457
|
bos@40
|
458 See also: \hook{incoming} (section~\ref{sec:hook:incoming}),
|
bos@40
|
459 \hook{prechangegroup} (section~\ref{sec:hook:prechangegroup}),
|
bos@40
|
460 \hook{pretxnchangegroup} (section~\ref{sec:hook:pretxnchangegroup})
|
bos@39
|
461
|
bos@39
|
462 \subsection{The \hook{commit} hook}
|
bos@39
|
463 \label{sec:hook:commit}
|
bos@39
|
464
|
bos@40
|
465 This hook is run after a new changeset has been created.
|
bos@40
|
466
|
bos@40
|
467 Parameters to this hook:
|
bos@40
|
468 \begin{itemize}
|
bos@40
|
469 \item[\texttt{node}] A changeset ID. The changeset ID of the newly
|
bos@40
|
470 committed changeset.
|
bos@40
|
471 \item[\texttt{parent1}] A changeset ID. The changeset ID of the first
|
bos@40
|
472 parent of the newly committed changeset.
|
bos@40
|
473 \item[\texttt{parent2}] A changeset ID. The changeset ID of the second
|
bos@40
|
474 parent of the newly committed changeset.
|
bos@40
|
475 \end{itemize}
|
bos@40
|
476
|
bos@40
|
477 See also: \hook{precommit} (section~\ref{sec:hook:precommit}),
|
bos@40
|
478 \hook{pretxncommit} (section~\ref{sec:hook:pretxncommit})
|
bos@40
|
479
|
bos@40
|
480 \subsection{The \hook{incoming} hook}
|
bos@40
|
481 \label{sec:hook:incoming}
|
bos@40
|
482
|
bos@40
|
483 This hook is run after a pre-existing changeset has been added to the
|
bos@40
|
484 repository, for example via a \hgcmd{push}. If a group of changesets
|
bos@40
|
485 was added in a single operation, this hook is called once for each
|
bos@40
|
486 added changeset.
|
bos@40
|
487
|
bos@40
|
488 Parameters to this hook:
|
bos@40
|
489 \begin{itemize}
|
bos@40
|
490 \item[\texttt{node}] A changeset ID. The ID of the newly added
|
bos@39
|
491 changeset.
|
bos@40
|
492 \end{itemize}
|
bos@40
|
493
|
bos@40
|
494 See also: \hook{changegroup} (section~\ref{sec:hook:changegroup}) \hook{prechangegroup} (section~\ref{sec:hook:prechangegroup}), \hook{pretxnchangegroup} (section~\ref{sec:hook:pretxnchangegroup})
|
bos@40
|
495
|
bos@40
|
496 \subsection{The \hook{outgoing} hook}
|
bos@40
|
497 \label{sec:hook:outgoing}
|
bos@40
|
498
|
bos@40
|
499 This hook is run after a group of changesets has been propagated out
|
bos@40
|
500 of this repository, for example by a \hgcmd{push} or \hgcmd{bundle}
|
bos@40
|
501 command.
|
bos@40
|
502
|
bos@40
|
503 Parameters to this hook:
|
bos@40
|
504 \begin{itemize}
|
bos@40
|
505 \item[\texttt{node}] A changeset ID. The changeset ID of the first
|
bos@40
|
506 changeset of the group that was sent.
|
bos@40
|
507 \item[\texttt{source}] A string. The source of the of the operation.
|
bos@40
|
508 If a remote client pulled changes from this repository,
|
bos@40
|
509 \texttt{source} will be \texttt{serve}. If the client that obtained
|
bos@40
|
510 changes from this repository was local, \texttt{source} will be
|
bos@40
|
511 \texttt{bundle}, \texttt{pull}, or \texttt{push}, depending on the
|
bos@40
|
512 operation the client performed.
|
bos@40
|
513 \end{itemize}
|
bos@40
|
514
|
bos@40
|
515 See also: \hook{preoutgoing} (section~\ref{sec:hook:preoutgoing})
|
bos@40
|
516
|
bos@40
|
517 \subsection{The \hook{prechangegroup} hook}
|
bos@40
|
518 \label{sec:hook:prechangegroup}
|
bos@40
|
519
|
bos@40
|
520 This hook is not passed any parameters.
|
bos@40
|
521
|
bos@40
|
522 See also: \hook{changegroup} (section~\ref{sec:hook:changegroup}),
|
bos@40
|
523 \hook{incoming} (section~\ref{sec:hook:incoming}), ,
|
bos@40
|
524 \hook{pretxnchangegroup} (section~\ref{sec:hook:pretxnchangegroup})
|
bos@40
|
525
|
bos@40
|
526 \subsection{The \hook{precommit} hook}
|
bos@40
|
527 \label{sec:hook:precommit}
|
bos@40
|
528
|
bos@40
|
529 This hook is invoked before Mercurial has obtained any of the metadata
|
bos@40
|
530 for the commit, such as the commit message or date.
|
bos@40
|
531
|
bos@40
|
532 Parameters to this hook:
|
bos@40
|
533 \begin{itemize}
|
bos@40
|
534 \item[\texttt{parent1}] A changeset ID. The changeset ID of the first
|
bos@40
|
535 parent of the working directory.
|
bos@40
|
536 \item[\texttt{parent2}] A changeset ID. The changeset ID of the second
|
bos@40
|
537 parent of the working directory.
|
bos@40
|
538 \end{itemize}
|
bos@40
|
539 If the commit proceeds, the parents of the working directory will
|
bos@40
|
540 become the parents of the new changeset.
|
bos@40
|
541
|
bos@40
|
542 See also: \hook{commit} (section~\ref{sec:hook:commit}),
|
bos@40
|
543 \hook{pretxncommit} (section~\ref{sec:hook:pretxncommit})
|
bos@40
|
544
|
bos@40
|
545 \subsection{The \hook{preoutgoing} hook}
|
bos@40
|
546 \label{sec:hook:preoutgoing}
|
bos@40
|
547
|
bos@40
|
548 This hook is invoked before Mercurial knows the identities of the
|
bos@40
|
549 changesets to be transmitted.
|
bos@40
|
550
|
bos@40
|
551 Parameters to this hook:
|
bos@40
|
552 \begin{itemize}
|
bos@40
|
553 \item[\texttt{source}] A string. The source of the operation that is
|
bos@40
|
554 attempting to obtain changes from this repository. See the
|
bos@40
|
555 documentation for the \texttt{source} parameter to the
|
bos@40
|
556 \hook{outgoing} hook, in section~\ref{sec:hook:outgoing}, for
|
bos@40
|
557 possible values of this parameter..
|
bos@40
|
558 \end{itemize}
|
bos@40
|
559
|
bos@40
|
560 See also: \hook{outgoing} (section~\ref{sec:hook:outgoing})
|
bos@40
|
561
|
bos@40
|
562 \subsection{The \hook{pretag} hook}
|
bos@40
|
563 \label{sec:hook:pretag}
|
bos@40
|
564
|
bos@40
|
565 Parameters to this hook:
|
bos@40
|
566 \begin{itemize}
|
bos@40
|
567 \item[\texttt{local}] A boolean. Whether the tag is local to this
|
bos@40
|
568 repository instance (i.e.~stored in \sfilename{.hg/tags}) or managed
|
bos@40
|
569 by Mercurial (stored in \sfilename{.hgtags}).
|
bos@40
|
570 \item[\texttt{node}] A changeset ID. The ID of the changeset to be tagged.
|
bos@40
|
571 \item[\texttt{tag}] A string. The name of the tag to be created.
|
bos@40
|
572 \end{itemize}
|
bos@40
|
573
|
bos@40
|
574 If the tag to be created is revision-controlled, the \hook{precommit}
|
bos@40
|
575 and \hook{pretxncommit} hooks (sections~\ref{sec:hook:commit}
|
bos@40
|
576 and~\ref{sec:hook:pretxncommit}) will also be run.
|
bos@40
|
577
|
bos@40
|
578 See also: \hook{tag} (section~\ref{sec:hook:tag})
|
bos@40
|
579
|
bos@40
|
580 \subsection{The \hook{pretxnchangegroup} hook}
|
bos@40
|
581 \label{sec:hook:pretxnchangegroup}
|
bos@40
|
582
|
bos@40
|
583 Parameters to this hook are the same as for the \hook{changegroup}
|
bos@40
|
584 hook; see section~\ref{sec:hook:changegroup} for details.
|
bos@40
|
585
|
bos@40
|
586 See also: \hook{changegroup} (section~\ref{sec:hook:changegroup}),
|
bos@40
|
587 \hook{incoming} (section~\ref{sec:hook:incoming}),
|
bos@40
|
588 \hook{prechangegroup} (section~\ref{sec:hook:prechangegroup})
|
bos@40
|
589
|
bos@40
|
590 \subsection{The \hook{pretxncommit} hook}
|
bos@40
|
591 \label{sec:hook:pretxncommit}
|
bos@40
|
592
|
bos@40
|
593 Parameters to this hook are the same as for the \hook{commit} hook;
|
bos@40
|
594 see section~\ref{sec:hook:commit} for details.
|
bos@40
|
595
|
bos@40
|
596 See also: \hook{precommit} (section~\ref{sec:hook:precommit})
|
bos@40
|
597
|
bos@40
|
598 \subsection{The \hook{preupdate} hook}
|
bos@40
|
599 \label{sec:hook:preupdate}
|
bos@40
|
600
|
bos@40
|
601 Parameters to this hook:
|
bos@40
|
602 \begin{itemize}
|
bos@40
|
603 \item[\texttt{parent1}] A changeset ID. The ID of the parent that the
|
bos@40
|
604 working directory is to be updated to. If the working directory is
|
bos@40
|
605 being merged, it will not change this parent.
|
bos@40
|
606 \item[\texttt{parent2}] A changeset ID. Only set if the working
|
bos@40
|
607 directory is being merged. The ID of the revision that the working
|
bos@40
|
608 directory is being merged with.
|
bos@40
|
609 \end{itemize}
|
bos@40
|
610
|
bos@40
|
611 See also: \hook{update} (section~\ref{sec:hook:update})
|
bos@40
|
612
|
bos@40
|
613 \subsection{The \hook{tag} hook}
|
bos@40
|
614 \label{sec:hook:tag}
|
bos@40
|
615
|
bos@40
|
616 Parameters to this hook are the same as for the \hook{pretag} hook;
|
bos@40
|
617 see section~\ref{sec:hook:pretag} for details.
|
bos@40
|
618
|
bos@40
|
619 If the created tag is revision-controlled, the \hook{commit} hook
|
bos@40
|
620 (section~\ref{sec:hook:commit}) will also be run.
|
bos@40
|
621
|
bos@40
|
622 See also: \hook{pretag} (section~\ref{sec:hook:pretag})
|
bos@40
|
623
|
bos@40
|
624 \subsection{The \hook{update} hook}
|
bos@40
|
625 \label{sec:hook:update}
|
bos@40
|
626
|
bos@40
|
627 \begin{itemize}
|
bos@40
|
628 \item[\texttt{error}] A boolean. Indicates whether the update or
|
bos@40
|
629 merge completed successfully.
|
bos@40
|
630 \item[\texttt{parent1}] A changeset ID. The ID of the parent that the
|
bos@40
|
631 working directory was updated to. If the working directory was
|
bos@40
|
632 merged, it will not have changed this parent.
|
bos@40
|
633 \item[\texttt{parent2}] A changeset ID. Only set if the working
|
bos@40
|
634 directory was merged. The ID of the revision that the working
|
bos@40
|
635 directory was merged with.
|
bos@40
|
636 \end{itemize}
|
bos@40
|
637
|
bos@40
|
638 See also: \hook{preupdate} (section~\ref{sec:hook:preupdate})
|
bos@34
|
639
|
bos@34
|
640 %%% Local Variables:
|
bos@34
|
641 %%% mode: latex
|
bos@34
|
642 %%% TeX-master: "00book"
|
bos@34
|
643 %%% End:
|