Update time stamps of different kind

Update time stamps of different kind

[Uwe Siart]

Dear all,

I have (add-hook 'before-save-hook 'time-stamp) in my site-start.el in
order to automatically update the time stamp before saving.

Is it also possible to instruct Emacs to update a line like

  <meta name="DC.date" content="2009-07-15" />

(Dublin Core meta data in XHTML) in the same way?

-- 
Uwe

Re: Update time stamps of different kind

[Peter Dyballa]

Am 15.07.2009 um 16:23 schrieb Uwe Siart:

> Is it also possible to instruct Emacs to update a line like
>
>   <meta name="DC.date" content="2009-07-15" />
>
> (Dublin Core meta data in XHTML) in the same way?

I presume only the date of the content clause needs updates…

For this a variable exists which you can customise:

	time-stamp-format is a variable defined in `time-stamp.el'.
	Its value is
	"%:y-%02m-%02d %02H:%02M:%02S %u"
	
	  This variable is safe as a file local variable if its value
	  satisfies the predicate `stringp'.

Making it a file local variable you can have as global setting  
something else. For you "%:y-%02m-%02d" might be right! The time  
stamp needs to be in the first few lines of a file.

--
Mit friedvollen Grüßen

   Pete

Atheism is a non prophet organization.

Re: Update time stamps of different kind

[Uwe Siart]

Peter Dyballa <Peter_Dyballa@Web.DE> writes:

> Making it a file local variable you can have as global setting
> something else. For you "%:y-%02m-%02d" might be right!

Thank you, Peter. From this I conclude that there's no easy way to get
both, the usual time stamp in its default format "%:y-%02m-%02d
%02H:%02M:%02S %u" plus the meta information updated?

> The time stamp needs to be in the first few lines of a file.

Is it possible to overcome this limitation? I mean to extend the
possible area from the first 8 lines to, say, the first 20 lines?

-- 
Uwe

RE: Update time stamps of different kind

[Drew Adams]

> > Making it a file local variable you can have as global setting
> > something else. For you "%:y-%02m-%02d" might be right!
> 
> Thank you, Peter. From this I conclude that there's no easy way to get
> both, the usual time stamp in its default format "%:y-%02m-%02d
> %02H:%02M:%02S %u" plus the meta information updated?
> 
> > The time stamp needs to be in the first few lines of a file.
> 
> Is it possible to overcome this limitation? I mean to extend the
> possible area from the first 8 lines to, say, the first 20 lines?

I don't have time to check exactly what you want to do and how to do it, but you
might want to take a look here:
http://www.emacswiki.org/emacs/AutomaticFileHeaders#header2
http://www.emacswiki.org/emacs/header2.el

That code uses a custom time stamp, with no limit on where you put it.

See also function `format-time-string'. You can use it to get a time stamp of
various forms - quite flexible.

Re: Update time stamps of different kind

[Peter Dyballa]

Am 15.07.2009 um 18:35 schrieb Uwe Siart:

> Thank you, Peter. From this I conclude that there's no easy way to get
> both, the usual time stamp in its default format "%:y-%02m-%02d
> %02H:%02M:%02S %u" plus the meta information updated?

It is my default value. I don't know what mean with "meta  
information" – is it that you want to see "<some text> <a date>?" IMO  
it should be possible to have a format like

	"<some funny text> %:y-%02m-%02d <even more funny text!>"

Look up the documentation for details! (C-h v when the text cursor is  
in the variable's name)

>
>> The time stamp needs to be in the first few lines of a file.
>
> Is it possible to overcome this limitation? I mean to extend the
> possible area from the first 8 lines to, say, the first 20 lines?

Sorry, I don't know (and I'm in a hurry). Could be time-stamp.el  
offers something.

--
Mit friedvollen Grüßen

   Pete       (:
         _    / __    -    -
       _/ \__/_/        -     -
      (´`)      (´`)   -    -
       `´        `´

Re: Update time stamps of different kind

[Uwe Siart]

Peter Dyballa <Peter_Dyballa@Web.DE> writes:

> I don't know what mean with "meta information" – is it that you want
> to see "<some text> <a date>?"

Sorry, this was not in proper context. With "meta information" in mean
the HTML meta tag I mentioned in my OP.

What I would like to reach is the following: In HTML files I have both
the full Emacs time stamp and an HTML meta tag that is read by index
bots. So what I want is that both lines

,----
| <!-- Time-stamp: "2009-07-08 09:19:15 siart" -->
|     <meta name="DC.date" content="2009-07-08" />
`----

are updated on save. But as I understand this difficult because
time-stamp-format can of course have just one value at a time.

I will check what I can do with header2.el.

-- 
Uwe

Re: Update time stamps of different kind

[Peter Dyballa]

Am 15.07.2009 um 19:44 schrieb Uwe Siart:

> ,----
> | <!-- Time-stamp: "2009-07-08 09:19:15 siart" -->
> |     <meta name="DC.date" content="2009-07-08" />
> `----


I found kind of a work-around, which does not work correctly! Maybe  
it gives you some hints…


I changed the two-liner to:

	 <meta name="DC.date" content="2009-07-15" />   <!-- "2009-07-13  
00:10:18 dunno" -->

and the file's tail to:

	</body>
	
	<!-- Local Variables: -->
	<!-- eval: (add-hook 'write-file-hooks 'time-stamp) -->
	<!-- eval: (add-hook 'write-file-hooks 'delete-trailing-whitespace) -->
	<!-- mode: html-helper -->
	<!-- fill-column: 99999 -->
	<!-- time-stamp-start: "    <meta name=\"DC.date\" content=\"" -->
	<!-- time-stamp-format: "%:y-%02m-%02d\" />   <!-- \"%:y-%02m-%02d % 
02H:%02M:%02S %u" -->
	<!-- End: -->
	
	</html>

If time-stamp is not in global write-file-hooks it's added here  
locally. Also the function delete-trailing-whitespace is added (which  
is not safe by default, you'll need to declare it as save by typing  
``!´´ when you're prompted). The mode line is not that meaningful,  
that with fill-column neither, just examples. The local variable time- 
stamp-start overrides the default "Timestamp" value. Here part of the  
standard header is defined as local substitute. Next comes the real  
time-stamp-format. Maybe it's possible to insert a newline there…

A final setting of time-stamp-end is also possible.


The HTML test file with these additions loads OK in GNU Emacs and  
displays OK in an HTML browser. When I save the file *Messages* shows:

	Saving file ....silly.html...
	timestamp delimiter start was not found

and the header now is something like this:

	    <meta name="DC.date" content="2009-07-16" />   <!-- "2009-07-16  
01:38:56 pete" />   <!-- "2009-07-16 01:38:56 pete" />   <!--  
"2009-07-13 00:10:18 dunno" -->

So repetition due to some malfunction/error exists! The `` -->´´ in  
the footer are not wrong or too much, they're needed. Maybe a block  
comment for the local variables section is better.

--
Mit friedvollen Grüßen

   Pete

Specifications are for the weak and timid!

Re: Update time stamps of different kind

[Uwe Siart]

Peter Dyballa <Peter_Dyballa@Web.DE> writes:

> Am 15.07.2009 um 19:44 schrieb Uwe Siart:
>
>> ,----
>> | <!-- Time-stamp: "2009-07-08 09:19:15 siart" -->
>> |     <meta name="DC.date" content="2009-07-08" />
>> `----
>
> I found kind of a work-around, which does not work correctly! Maybe it
> gives you some hints…
>
> [...]
>
> So repetition due to some malfunction/error exists! The `` -->´´ in
> the footer are not wrong or too much, they're needed. Maybe a block
> comment for the local variables section is better.

Many thanks for your efforts. I will take inspirations from your
suggestions which seem to be very close to what I need.

-- 
Uwe