24 Dec
2009
24 Dec
'09
10:43 a.m.
To be even more precise, with the algorithm I currently have the
following rules apply:
* An attachment name cannot contain a "@" (it has to be escaped)
* A page name cannot contain a "." (it has to be escaped)
* A space name cannot contain a ":" (it has to be escaped)
The general rule is that a given entity reference name cannot contain
the separator for separating from its parent entity reference (it has
to be escaped).
These are pretty simple rules IMO (and this is one reason why you
cannot "skip" an entity reference separator as in "wiki:page").
Thanks
-Vincent
On Dec 23, 2009, at 3:42 PM, Vincent Massol wrote:
Hi,
Since I'm writing the new Model part for Entity References (document
and attachment for now but we can imagine objects and object
properties later on). I'd like to propose 2 things:
* A syntax for escaping special characters in references
* Some changes to the supported reference syntax
Escapes
=======
I'd like to propose using the backslash (i.e. \ ) character.
For example: "a page name with \: some \. special \@ characters"
Rationale:
* it's a well known char for escapes, all devs know about it
* using "~" would be confusing with the wiki syntax
Known issue:
* when in the velocity macro you need to be careful to use a double
escape since \ is the velocity char for escaping. Ex:
{{velocity}}
[[label>>special\\@page-name]]
{{/velocity}}
Breakages
=========
Since we'll know have a generic factory/serializer for all entity
types we need to make the syntax more consistent. This means that
the following syntax will not work anymore:
* ex: "wiki:page". This would be interpreted as a document with a
page of "page" and a space of "wiki:"
* When using the "default" factory, only default values would be
used (right now it's a mix between current doc values and default
values). Suggested defaults: "xwiki" for Wiki, "XWiki" for space,
"WebHome" for page and "" for attachment name. Note that one idea is
to make these defaults configurable in the xwiki config file
* It's hard to know for sure but we certainly have various other
inconsistencies that exist now when using special reserved chars in
references
We have 2 options here:
* Make XE 2.2 not backward compatible for some references. Advertise
it in the release notes and explain to users how they should change
their names if they use "exotic" names
* Create an automatic converter, for example as a database migrator
that would read all documents in the wiki, call getLinks() on each
document, send the links to the old parser (would need to extract it
somewhere and ensure it behaves as now) and send the link to the new
parser and compare. If there's a difference, escape the char and
save. This would also need to be done for document parent
references, the backlink table and all object properties that allow
wiki syntax or velocity. Note that it wouldn't fix any generated
name (using velocity for ex).
The automatic converter option is really hard to do so I'm leaning
more towards the first solution. That would need to be properly
handled since it could potentially cause quite a few broken links.
WDYT?
Thanks
-Vincent