MoinMoin stores all the pages as plain text files in a shared
directory with the name “pages”. Each page has a subdirectory whose name
is derived from the page’s name. In the “revisions” subsubdirectory, the
different revisions of a page are stored. The current version of
Moin2Tiki handles only the current revision. This means that different
revisions aren’t supported (yet). Moin2Tiki, in the current version,
doesn’t touch any other MoinMoin data than what’s in that
pages directory.
Tiki stores its pages in a MySQL/MariaDB database. This database is
accessed from the PHP scripts which constitute the Tiki engine. In order
to store pages in the database, Moin2Tiki uses a PHP script, called
moin-import.php, which calls the respective Tiki PHP
scripts, which access the database. This script must be placed in the
Tiki top directory, together with all the other top-level Tiki PHP
scripts.
Moin2Tiki reads the selected MoinMoin pages and parses them. Then,
for each page, it generates a Tiki page which recreates the
corresponding MoinMoin page. These pages, together with any attachments
of the original pages, are fed into the moin-import.php
script, which stores them in the Tiki database.
Attachments are imported to Tiki only, when there isn’t already an attachment with the same name. When there is, the two aren’t compared. It is assumed that you’re trying to import new pages to Tiki, not replace existing ones. But you can do that. When there already is a page with the same name, the imported one is saved as a new revision of that page.
The Moin2Tiki program, “moin2tiki”, is to be run as the
web server’s user. This is because it needs access to the Tiki
installation. The user usually has the name “www-data”. You should use
the command sudo -uwww-user /path/to/moin2tiki ... to call
Moin2Tiki. This means that the WWW user must have the permissions to
read and execute the moin-import.php script.
There are quite a few parameters, which the Moin2Tiki program takes -
see Invocation. You are encouraged to
write a script which calls it, which sets all the parameters. There’s
moin2tiki.sh as an example.
The moin2tiki program takes exactly one action when it
is called. The main action is migrate, which migrates
MoinMoin pages to Tiki. Other notable actions are
listmoin/listtiki, which will show you which
pages you have selected. And ignore for pages you don’t
want to migrate.
Run moin2tiki help for a list of all the actions and
other options.
Apart from an action, moin2tiki also requires some
pages, to be selected, to operate on. (Except for the help
and license actions).
See Invocation for more details.
The biggest limitation on Moin2Tiki is, for now, that only one user
is supported. See Limitations. You need
to create this user in Tiki. The name of that user must be specified to
the moin2tiki program. See Invocation.
Before calling moin-import.php, the
moin2tiki program creates an intermediate directory
structure, which contains the converted pages and symbolic links to the
attachments. The attachments are stored by MoinMoin in the pages
directory (inside subsubdirectories called “attachments”, for each
page). The moin-import.php script scans this intermediate
directory structure and uses it to feed the data into the Tiki database.
Since the moin-import.php script is run as the same user as
the main moin2tiki program, the WWW user must have read
permissions for the MoinMoin pages directory.
You normally don’t catch sight of this intermediate directory,
because it is be removed after a migration. If you want to see it
without doing any migration, you can create it with the
create action. It won’t be deleted like after a migration
run, then. But you need to delete it, or move it out of the way, before
the next time you do something.
The ignore list is a text file of MoinMoin page names, one per line, which are ignored by all Moin2Tiki actions. This list can be used to track which pages have already been migrated. You can also use it to specify that some pages should not be migrated, by using the “ignore” action. This way you don’t need to migrate all pages at once.
There are two options for the ignore list(s).
--ignore-list-read specifies the ignore list, which is to
be read before executing the selected action. The pages listed in it
will be ignored. The --ignore-list-write option specifies
an ignore list, to which the names of successfully migrated MoinMoin
pages will be appended. You can also explicitly add pages to the ignore
list with the ignore action. Then the selected pages will
just be added to the ignore list, without migrating them.
Both lists can be the same file.
It doesn’t hurt, however, to import the same pages several times. When a page is imported, Moin2Tiki compares its content with the last version of the page, which is already there (if any). When the two are identical, the page is skipped and not migrated again.
The moin-import.php script writes a list of all
successfully migrated Tiki pages, called the “success list”. This list
is then read by moin2tiki and converted backwards to a list
of successfully migrated MoinMoin pages. These MoinMoin page names are
appended to the ignore list (see above).
MoinMoin has the advantage that all characters, except for the slash, can be used in page names. The slash separates page name components for hierachical page names. Tiki doesn’t have as much flexibility. The following characters are called “problematic” in page names:
/ ? # [ ] @ $ & + ; = < > ”
Moin2Tiki rewrites the MoinMoin page names such that these characters don’t occur any longer. For this, a file called the “replacements file” is being used. It is meant for replacing “problematic” characters, or character sequences, in MoinMoin page names with allowed character sequences in the Tiki page names. But it can also be used for replacements of any character sequences.
The replacements file contains a list of rules for how to replace
sequences of characters, one per line. Each rule consists of a character
sequence to be replaced and one to replace it. The two sequences are
strings, enclosed in quotes and they are separated by
->.
Any problematic characters that aren’t replaced by the rules in the replacements file, get replaced with underscores.
What happens when two distinct MoinMoin page names are translated to the same Tiki page name? This is possible. In this case, the two are made unique by adding a number at the end.
Tiki has something similar to MoinMoin’s hierarchical page names. It’s called “namespaces”. Like the slash in MoinMoin, they have a separator of the page name components. Unlike MoinMoin, this separator can be a string, not just one character. And it isn’t unchangable, but can be configured (like most things in Tiki).
The separator can be chosen in the Tiki control panels. See Preparations. The default namespace
separator is :_:. This isn’t very pretty. ::
can be used as the separator, but this is already used for centering
text. Therefore there is the Tiki option to change the markup for
centering text to :::. This can’t be done retroactively.
When you already have Tiki pages, which use the old namespace separator,
then you’re stuck with it, since the pages won’t automatically be
rewritten to use a new separator.
You specify the namespace separator for Moin2Tiki with the
--pathsep option. When you use :: as it, then
Moin2Tiki also assumes that ::: is used for centering
text.
The slash can’t be used as the namespace separator.
MoinMoin pages can make use of the attachments in any page. The attachments don’t need to be in the same pages as the links to them. So we have two sorts of pages when migrating from MoinMoin to Tiki. First, we have the selected pages. They can have attachments. Second, we have references to attachements in other, non-selected pages. The pages in which those external attachments are stored, are called “extra pages” in Moin2Tiki.
When migrating from MoinMoin to Tiki, the regular pages as well as the extra pages must be considered. This means that you get your migrated pages and, additionally, the extra pages in Tiki. The latter are empty, only their attachments are in use.
When you later select extra pages to be migrated, they are created as regular pages. The empty page will be replaced by the new, migrated page, so you won’t get an empty first revision for extra pages.
Pages that are deleted in MoinMoin aren’t really dead. The page isn’t deleted, only the current revision is removed. When you create a new page with the same name, the rest of the revisions of the “deleted” page come back to life.
I call those not quite deleted pages “zombie pages”. They are ignored by Moin2Tiki. When you start moin2tiki for the first time, you get messages about the detected zombie pages. When you chose to add the processed pages to the ignore list, then the zombie pages will be added to the list of pages which are being ignored, and you won’t get the messages about zombie pages again. If this is all what you want, you can select no pages and use the “ignore” action.