[pmwiki-users] PTVs on multiple lines

[Petko Yotov]

On 2015-10-18 22:39, Hans Bracker wrote:
> Hello Petko,
> 
> Sunday, October 18, 2015, 7:57:44 PM, you wrote:
> 
>> (:hidden:
>> var1: value 1
>> var2: value 2
>> var3: value 3
>> etc:)
> 
>> As long as the {$:hidden} variable contains all text, this is not a 
>> bug.
> 
> Yes the hidden PTV contains all text, and is okay.
> 
> But see this as example addition at the top here (I put it with
> (:linebreaks:) to make the presentation clearer):
> http://www.pmwiki.org/wiki/Test/MultilinePTVs
> 
> (:linebreaks:)
> (:hidden:
> var1: value 1
> var2: value 2
> var3: value 3
> etc:)
> 
> {$:hidden}
> {$:var1}
> {$:var2}
> {$:var3}
> {$:etc}
> 
> renders as
> 
> var1: value 1
> var2: value 2
> var3: value 3
> etc
> value 1
> value 2
> value 3
> )
> 
> The hidden PTV contains not three text PTVs, but four. The last one
> renders as the closing ')' character. I think this last etc:)
> should not render as text PTV. I see this as a bug in the text PTV
> definition. Or a bug in th eprocess how the text is scanned for
> matches to the PTV patterns.

When something works exactly the way it was intended and designed to 
work, like here, I wouldn't call it a bug. :-)

If there is a potential case where a new unrequested "etc" variable will 
be created with the value ")", there is also a potential case where a 
required variable will start with ")". In the both cases I fail to see a 
problem with the current core; if we modify the core to ignore a 
variable starting with ")", I can imagine problems. I prefer not to 
change it at this point.

If I fear that a multiline hidden PTV at its last line can overwrite an 
earlier single-line PTV, I wouldn't write such PTVs in my pages. :-)

Moreover, if my page doesn't have name:value but only (:name:value:) 
variables, the last line of the variable cannot overwrite another 
variable:

(:test:single line test:)
(:test2:multi
line
test:)

In this case "{$:test}" is "single line test" and not ")". If there is a 
chance for overwriting, I'd only use one type of variables in my pages.

If I use a form processor and fear that a user may write such a value, I 
would select longer unique PTV names, less likely to be overwritten, eg. 
"text_1337" instead of "text". It's the processor that handles it, 
transparently for the user.

Or even, I can redefine $PageTextVarPatterns['(:var:...:)'] to use 
something different than colons, for example (=name=value=) or 
(;name;value;). That wouldn't interfere with the :name:value single line 
definitions. (Make sure you also update the 'textvar:' Markup() 
definition from stdmarkup.php.)

Petko

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