Metatags in header file

Meta information of every page controlled by a single header file

[Antara]

I'm managing a particular website where the Meta information is located in one header.php file.
This practically retards the possibility of targeting each page with a separate set of metatags.
One of my developers suggested to write all the metatags in the header.php file by using session value.
Is that a feasible option? Would the search engine spiders in this case read them as separate metatags for each page ?
If not, is there any other possible option to manage this ?

Just thought to mention, the site is designed in Cake php.

[phranque]

the metatag value should be based on the content of the url being requested rather than the current session.

the search engine spiders will read the metatags that are served with the document they are requesting with that url.

[goodroi]

phranque is correct meta data should be based on page content & not session.

technically it is probably possible to use session value, but i wouldnt do it that way. i see alot of complications and many ways it can go wrong. i could see it worst case triggering the search engine spam filters and leading to a possible penalty.

[Propools]

Where is the header.php file usually located on a server?

[Antara]

Thanks for replying.
@Propools: In my case, this header.php file is located in the web root itself

@Goodroi, phranque: I understand...yes, it does show the spiders the metatags when that particular page is requested. I guess the Metatags would then have a bearing in the optimization process.
But is there any other way to do this ? I really wouldn't want to trigger the search engine spam filters. Sigh.