doc/todo/Auto-setup_and_maintain_Mercurial_wrapper_hooks.mdwn

   1 Attempt to fix a `TODO` in `Automator.pm` in combination with the Mercurial backend.
   2
   3 1. To define hooks, Mercurial uses paths given in the config file `.hg/hgrc`. To enable Mercurial to call `ikiwiki-wrapper` automatically after blog/wiki setup, ikiwiki thus needs to create `hgrc`.
   4 2. To reflect changes in `$config{srcdir}` and/or `$config{mercurial_wrapper}`, relevant lines in `hgrc` need to be updated on wrapper creation.
   5
   6 ikiwiki can keep track of lines in `hgrc` for which it is responsible by adding a `.ikiwiki` suffix to its hooks. This is correct and recommended markup, Mercurial-wise.
   7
   8 Two ways follow below. I prefer the long one. --[[Daniel Andersson]]
   9
  10 > I comment myself: this can probably be solved without adding ad-hoc hooks and stuff (maybe not as "correct" as changing the config file only directly after wrappers have been generated, but good enough). I have a large rewrite of `mercurial.pm` ready, currently under local testing before I upload it for comments, trying to make it equal in function to `git.pm`. Comments below are of course welcome, but I will look into other ways of solving it later. Maybe `rcs_checkconfig` or `rcs_genwrapper` should host the `hgrc`-changing code. --[[Daniel Andersson]]
  11
  12 Compact way (addresses only point 1)
  13 ------------------------------------
  14 [This patch at pastebin](http://pastebin.com/by9f4dwX) ([raw version](http://pastebin.com/raw.php?i=by9f4dwX)).
  15
  16 Set default `ikiwiki-wrapper` path.
  17
  18         diff -r 8faf136ca94f Setup/Automator.pm
  19         --- a/Setup/Automator.pm        Tue Jul 19 21:04:13 2011 +0200
  20         +++ b/Setup/Automator.pm        Wed Jul 20 15:33:21 2011 +0200
  21         @@ -75,8 +75,7 @@
  22                                 print STDERR "warning: do not know how to set up the bzr_wrapper hook!\n";
  23                         }
  24                         elsif ($config{rcs} eq 'mercurial') {
  25         -                       # TODO
  26         -                       print STDERR "warning: do not know how to set up the mercurial_wrapper hook!\n";
  27         +                       $config{mercurial_wrapper}=$config{srcdir}."/.hg/ikiwiki-wrapper";
  28                         }
  29                         elsif ($config{rcs} eq 'tla') {
  30                                 # TODO
  31
  32 Create `$config{srcdir}/.hg/hgrc` with hook info during auto-installation script. Use relative paths to not require manual `hgrc` intervention if `$config{srcdir}` is changed. If `$config{mercurial_wrapper}` is changed, manual edit of `hgrc` is needed to catch the new wrapper path.
  33
  34 (Is there a security risk with relative paths?)
  35
  36         @@ -187,6 +186,22 @@
  37                         die "ikiwiki --wrappers --setup $config{dumpsetup} failed";
  38                 }
  39
  40         +       # Setup initial config file for Mercurial to hook up the wrapper.
  41         +       if ($config{rcs} eq 'mercurial' && exists $config{mercurial_wrapper}
  42         +               && length $config{mercurial_wrapper}) {
  43         +               # Use a relative path to avoid having to manually change the
  44         +               # autogenerated hgrc if the user changes $config{srcdir}.
  45         +               use File::Spec;
  46         +               my $mercurial_wrapper_relpath=File::Spec->abs2rel($config{mercurial_wrapper}, $config{srcdir});
  47         +               open (HGRC, '>', $config{srcdir}.'/.hg/hgrc');
  48         +               print HGRC <<EOF;
  49         +[hooks]
  50         +post-commit.ikiwiki = $mercurial_wrapper_relpath
  51         +incoming.ikiwiki = $mercurial_wrapper_relpath
  52         +EOF
  53         +               close (HGRC);
  54         +       }
  55         +
  56                 # Add it to the wikilist.
  57                 mkpath("$ENV{HOME}/.ikiwiki");
  58                 open (WIKILIST, ">>$ENV{HOME}/.ikiwiki/wikilist") || die "$ENV{HOME}/.ikiwiki/wikilist: $!";
  59
  60
  61 Less compact but more robust way (addresses point 1 and 2)
  62 ----------------------------------------------------------
  63 [This complete patch at pastebin](http://pastebin.com/AcDHjbK6) ([raw version](http://pastebin.com/raw.php?i=AcDHjbK6)).
  64
  65 This way leaks onto additional files and adds general functionality that may or may not be wanted. The main part of the extra code is contained within `mercurial.pm`, though.
  66
  67 Set default `ikiwiki-wrapper` path.
  68
  69         diff -r b08179653c00 IkiWiki/Setup/Automator.pm
  70         --- a/IkiWiki/Setup/Automator.pm        Wed Jul 20 16:56:09 2011 +0200
  71         +++ b/IkiWiki/Setup/Automator.pm        Wed Jul 20 19:28:21 2011 +0200
  72         @@ -75,8 +75,7 @@
  73                                 print STDERR "warning: do not know how to set up the bzr_wrapper hook!\n";
  74                         }
  75                         elsif ($config{rcs} eq 'mercurial') {
  76         -                       # TODO
  77         -                       print STDERR "warning: do not know how to set up the mercurial_wrapper hook!\n";
  78         +                       $config{mercurial_wrapper}=$config{srcdir}."/.hg/ikiwiki-wrapper";
  79                         }
  80                         elsif ($config{rcs} eq 'tla') {
  81                                 # TODO
  82
  83 Create `$config{srcdir}/.hg/hgrc` during auto-installation with hook info.
  84
  85         @@ -182,6 +181,19 @@
  86                         }
  87                 }
  88
  89         +       # Setup initial config file for Mercurial to hook up the wrapper. The
  90         +       # path to the wrapper will be automatically added when it is generated.
  91         +       if ($config{rcs} eq 'mercurial' && exists $config{mercurial_wrapper}
  92         +               && length $config{mercurial_wrapper}) {
  93         +               open (HGRC, '>', $config{srcdir}.'/.hg/hgrc');
  94         +               print HGRC <<EOF;
  95         +[hooks]
  96         +post-commit.ikiwiki =
  97         +incoming.ikiwiki =
  98         +EOF
  99         +               close (HGRC);
 100         +       }
 101         +
 102                 # Add wrappers, make live.
 103                 if (system("ikiwiki", "--wrappers", "--setup", $config{dumpsetup}) != 0) {
 104                         die "ikiwiki --wrappers --setup $config{dumpsetup} failed";
 105
 106 `hgrc` is setup initially. Below follows code to keep `hgrc` updated.
 107
 108 Add backend specific function `rcs_wrapper_postcall()` for later call in `Wrappers.pm`.
 109
 110         diff -r b08179653c00 IkiWiki/Plugin/mercurial.pm
 111         --- a/IkiWiki/Plugin/mercurial.pm       Wed Jul 20 16:56:09 2011 +0200
 112         +++ b/IkiWiki/Plugin/mercurial.pm       Wed Jul 20 19:28:21 2011 +0200
 113         @@ -21,6 +21,7 @@
 114                 hook(type => "rcs", id => "rcs_diff", call => \&rcs_diff);
 115                 hook(type => "rcs", id => "rcs_getctime", call => \&rcs_getctime);
 116                 hook(type => "rcs", id => "rcs_getmtime", call => \&rcs_getmtime);
 117         +       hook(type => "rcs", id => "rcs_wrapper_postcall", call => \&rcs_wrapper_postcall);
 118          }
 119
 120          sub checkconfig () {
 121
 122 Pass variable to `gen_wrapper()` to decide if `rcs_wrapper_postcall()` should run. Default is `1` to update `hgrc`, since it is done non-intrusive (won't create `hgrc` if it doesn't exist, won't overwrite anything unless it is set by ikiwiki itself).
 123
 124         @@ -28,6 +29,7 @@
 125                         push @{$config{wrappers}}, {
 126                                 wrapper => $config{mercurial_wrapper},
 127                                 wrappermode => (defined $config{mercurial_wrappermode} ? $config{mercurial_wrappermode} : "06755"),
 128         +                       wrapper_postcall => (defined $config{mercurial_wrapper_hgrc_update} ? $config{mercurial_wrapper_hgrc_update} : "1"),
 129                         };
 130                 }
 131          }
 132
 133 Include default configuration value and comment.
 134
 135         @@ -53,6 +55,13 @@
 136                                 safe => 0,
 137                                 rebuild => 0,
 138                         },
 139         +               mercurial_wrapper_hgrc_update => {
 140         +                       type => "string",
 141         +                       example => "1",
 142         +                       description => "updates existing hgrc to reflect path changes for mercurial_wrapper",
 143         +                       safe => 0,
 144         +                       rebuild => 0,
 145         +               },
 146                         historyurl => {
 147                                 type => "string",
 148                                 example => "http://example.com:8000/log/tip/\[[file]]",
 149
 150 `hgrc` should be updated to point to the new wrapper path. The regexp transforms lines as e.g.
 151
 152         post-commit.ikiwiki = /home/daniel/blog/.hg/ikiwiki-wrapper-oldpath
 153         incoming.ikiwiki = /home/daniel/blog/.hg/ikiwiki-wrapper-oldpath
 154
 155 to
 156
 157         post-commit.ikiwiki = $config{mercurial_wrapper}
 158         incoming.ikiwiki = $config{mercurial_wrapper}
 159
 160 with absolute paths.
 161
 162         @@ -402,4 +411,23 @@
 163                 return findtimes($file, 0);
 164          }
 165
 166         +sub rcs_wrapper_postcall($) {
 167         +       # Update hgrc if it exists. Change post-commit/incoming hooks with the
 168         +       # .ikiwiki suffix to point to the wrapper path given in the setup file.
 169         +       # Work with a tempfile to not delete hgrc if the loop is interrupted
 170         +       # midway.
 171         +       my $hgrc=$config{srcdir}.'/.hg/hgrc';
 172         +       my $backup_suffix='.ikiwiki.bak';
 173         +       if (-e $hgrc) {
 174         +               use File::Spec;
 175         +               my $mercurial_wrapper_abspath=File::Spec->rel2abs($config{mercurial_wrapper}, $config{srcdir});
 176         +               local ($^I, @ARGV)=($backup_suffix, $hgrc);
 177         +               while (<>) {
 178         +                       s/^(post-commit|incoming)(\.ikiwiki[ \t]*=[ \t]*).*$/$1$2$mercurial_wrapper_abspath/;
 179         +                       print;
 180         +               }
 181         +               unlink($hgrc.$backup_suffix);
 182         +       }
 183         +}
 184         +
 185          1
 186
 187 `rcs_wrapper_postcall` is made available.
 188
 189         diff -r b08179653c00 IkiWiki.pm
 190         --- a/IkiWiki.pm        Wed Jul 20 16:56:09 2011 +0200
 191         +++ b/IkiWiki.pm        Wed Jul 20 19:28:21 2011 +0200
 192         @@ -2059,6 +2059,10 @@
 193                 $hooks{rcs}{rcs_getmtime}{call}->(@_);
 194          }
 195
 196         +sub rcs_wrapper_postcall (@) {
 197         +       $hooks{rcs}{rcs_wrapper_postcall}{call}->(@_);
 198         +}
 199         +
 200          sub rcs_receive () {
 201                 $hooks{rcs}{rcs_receive}{call}->();
 202          }
 203
 204
 205 `rcs_wrapper_postcall` is called if $config{wrapper_postcall} is true, which it should only be for Mercurial at the moment.
 206
 207         diff -r b08179653c00 IkiWiki/Wrapper.pm
 208         --- a/IkiWiki/Wrapper.pm        Wed Jul 20 16:56:09 2011 +0200
 209         +++ b/IkiWiki/Wrapper.pm        Wed Jul 20 19:28:21 2011 +0200
 210         @@ -238,6 +238,10 @@
 211                 }
 212                 #translators: The parameter is a filename.
 213                 debug(sprintf(gettext("successfully generated %s"), $wrapper));
 214         +
 215         +       if (defined $config{wrapper_postcall} && $config{wrapper_postcall} ) {
 216         +               IkiWiki::rcs_wrapper_postcall();
 217         +       }
 218          }
 219
 220          1