[ZCM] [ZC] 1095/ 4 Comment "ZPT error message with leading / in path"

[Collector: Zope Bugs, Features, and Patches ...]

Issue #1095 Update (Comment) "ZPT error message with leading / in path"
 Status Pending, Zope/bug medium
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  http://zope.org/Collectors/Zope/1095

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= Comment - Entry #4 by stevea on Oct 26, 2003 12:51 pm

I suggest the specification be amended to make a leading slash equivalent to "CONTEXTS/" at the start of an expression.

The CONTEXTS bound name is used when the name of a "context" such as "root", "here", "request" and so forth has been shadowed by a local definition. This seems to be very similar to an absolute path kind of thing.
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= Comment - Entry #3 by ianb on Oct 26, 2003 3:11 am

There's an analogy between URLs and path expressions -- an analogy that was deliberately encouraged by the use of "/".  This is a place where that analogy breaks down, even though it would be entirely reasonable if it actually worked (where /something was equivalent to root/something).  Where there's a potential inconsistency with reasonable programmer expectations, it's nice to give the programmer a hint of what they did wrong (which the current message does not do).
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= Comment - Entry #2 by ajung on Oct 26, 2003 2:57 am

If people would read the existing documentation then they would not 
get the idea to try "/template/title". So this is more a RTFM
issue and not  a requirement to change the code since path expresssions
are well defined and documented. 
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= Request - Entry #1 by ianb on Oct 25, 2003 11:34 pm

If you use a path with a leading slash, you get an error like:

TAL.TALDefs.TALError: Invalid variable name "" in expression '/template/title', at line 13, column 7

This is a very confusing error.  I would suggest a change in Expressions.py:119, that it test if base is empty, and if so then use a message that warns people that leading slashes are not allowed.  
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