[TYPO3-dev] An idea to further process ' page not found ' 404 handling
Matt K - [SwagmanInternet]
typo3 at swagmaninternet.com
Wed Apr 30 04:12:16 CEST 2008
Hi All,
I thought i would add a link here for anyone wishing to compare the original
class.tslib_fe.php file with a copy of class.tslib_fe.php that has mods
included.
http://www.swagmaninternet.com/downloads/compare_class.tslib_fe.php.zip
regards,
Matt K
SwagmanInternet.com
SwagmanInternet wrote:
> Hi all,
>
> Background.
>
> On and off over the last 2-3 weeks I have been working to get my TYPO3
> installs to properly process ' page not found ' 404 handling. I have
> read the information on this page
> http://typo3.org/development/articles/improved-404-handling/ and note
> that requested pages and resources that do not exist are redirected
> to the websites home page and do not respond with correct 404 http
> headers.
> So I have come up with the below comments and suggestions from my
> research and testing. Just in case I missed something in setting up
> 404 handling in my T3 site(s) working I tested out the example
> incorrect URLs listed below on a few random TYPO3 websites online and
> saw similar redirections to the index page of those TYPO3 installs
> too.
> If the below code suggestions are plausable perhaps they could be
> considered for the core?
>
> Your thoughts and comments appreciated.
>
> Regards,
>
> Matt
> SwagmanInternet.co
>
> --------------------------------------------------------------------
>
> 404 handling report & code suggestions in detail:
>
>
> After following the set up guide mentioned here
> http://typo3.org/development/articles/improved-404-handling/ and
> when using default TYPO3 .htaccess file and with or without 'simulate
> static documents' it appears that 404 pagenotfound_handling works
> only for requested files:
> - that have .html as the file suffix
> - and the file being called is requested from the root of a
> typo3 site, i.e. www.domain.com.au/file.html
>
> If 'file.html' exists, page is shown
>
> If 'wrongfile.html' does not exist then correct 404 handling takes
> place correctly, due to function '$this->checkAndSetAlias()'
>
> Correct 404 page error handling appears to fail for the following
> requested resources;
>
> - www.domain.com.au/file.htm
> - www.domain.com.au/file.pdf
>
> - www.domain.com.au/folder/
> - www.domain.com.au/folder/file.html
> - www.domain.com.au/folder/file.pdf
>
> -
> www.domain.com.au/file.htm?&tx_yourextension_pi1[showUid]=171
> -
> www.domain.com.au/folder/file.html?&tx_yourextension_pi1[showUid]=171
>
> If any of the above requested resources fail then the browser is
> redirected to the home page of website, the root page, due to
> $this->id being 'false' and then $this->id is set to '0' in function
> 'setIDfromArgV()'
> --------------------------------------------------------------------
>
> Suggested short-term workaround that appears to work before potential
> patch to 'class.tslib_fe.php'
>
> in .htaccess, modify to suit:
>
> AFTER lines
>
> RewriteCond %{REQUEST_FILENAME} !-f
> RewriteCond %{REQUEST_FILENAME} !-d
> RewriteCond %{REQUEST_FILENAME} !-l
>
> COMMENT OUT
>
> # RewriteRule .* index.php [L]
>
> ADD/CHANGE TO
>
> # If any file/dir/symlink does not exist, set id=000 , this
> value not likely to exist in the databases page table
> RewriteRule .* index.php?id=000 [L]
>
> ------------------------
>
> What happens in 'class.tslib_fe.php' , (after above .htaccess hack
> applied), when TYPO3 processes the page requested when you force an
> 'id=000' in the .htaccess file
>
> - firstly, the argument '000' is set to type 'string'
> - now when $this->id is processed by function
> checkAndSetAlias(), $this->pageNotFound is set to 4
> the if condition inside function checkAndSetAlias(), " if
> ($this->id && !t3lib_div::testInt($this->id)) ", is false when
> id=000
> - now that the var $this->pageNotFound has a value the
> following function is called
> $this->pageNotFoundAndExit($pNotFoundMsg[$this->pageNotFound])
> which now now executes the function
> $this->pageNotFoundHandler() and causes script to exit
>
> - Noting: if the following file is requested,
> 'www.domain.com.au/file.html',
> - $this->id is changed from 000 to the alias value in
> variable $fI['file'] in function checkAlternativeIdMethods()
> therefore alias formed by simulate static documents are
> still checked if exists in databse
>
>
> Testing scenarios for the short-term workaround.
>
> - all the above requested resources URLs, (inc working &
> failed URLs), applied in browser to test using short term fix to
> .htaccess file
> - tested using typo3 src v4.1.5 and no simulate static
> documents, i.e. www.domain.com.au/index.php?id=000
> - tested using typo3 src v4.1.5 and using simulate static
> documents, config.simulateStaticDocuments = 1
>
> - have not tested with realurl extension installed
>
> - this workaround works on typo3 src v4.1.5, potentially
> will work on previous versions of TYPO3 source, though this will
> depend on what changes, if any, exist between versions of
> 'class.tslib_fe.php'
> -----------------------------------------------------------
>
> Long term suggested solution for fixing 404 pagenotfound_handling:
>
> After reviewing code mainly in file 'class.tslib_fe.php',
> I suggest the following 2 code fixes/modifications in file
> 'class.tslib_fe.php'.
>
> ------------------------
>
> NEW function call added inside function fetch_the_id(), and also a
> 5th key=> value added to array $pNotFoundMsg
>
>
> // Checks if $this->id is false &&
> pageNotFound_handling enabled, if yes, then set $this->pageNotFound =
> 5 $this->checkAndSetPageNotFound();
>
> if ($this->pageNotFound &&
> $this->TYPO3_CONF_VARS['FE']['pageNotFound_handling']) {
> $pNotFoundMsg = array(
> 1 => 'ID was not an
> accessible page',
> 2 => 'Subsection was
> found and not accessible',
> 3 => 'ID was outside
> the domain',
> 4 => 'The requested
> page alias does not exist',
> 5 => 'The requested
> page or file resource does not exist'
> );
>
> -----------------------------------------------------------
>
> ALSO NEW function, inserted possibly below function
> ADMCMD_preview_postInit($previewConfig)
>
>
> /**
> * Checks if $this->id is false && pageNotFound_handling
> enabled, if yes, then set $this->pageNotFound = 5
> * When $this->pageNotFound set 5 the TYPO3 correctly
> redirects pageNotFound requests to value set in config
> $TYPO3_CONF_VARS['FE']['pageNotFound_handling']
> * this should only run when a file/symlink/directory does
> not exist and page was Redirected to index.php in .htaccess file
> *
> * @return void
> * @access private // should this be
> set private?
> * @see fetch_the_id()
> */
> function checkAndSetPageNotFound() {
> if (!$this->id &&
> $this->TYPO3_CONF_VARS['FE']['pageNotFound_handling'] &&
> !$this->pageNotFound == 4) {
> $this->pageNotFound =
> 5; }
> }
>
> -----------------------------------------------------------
> -----------------------------------------------------------
>
> Note:
>
> Don't forget to set html tag '<base href=...>', in your main ts
> templates config; This should be set so that when/if a page is called
> with a folder in its path and also page does not exist the browser is
> redirected to your TYPO3 index page. If your file resources do not
> have html tag '<base href=...>' or absolute paths set then this could
> cause the page resources, i.e. css files & images, relative paths to
> break and cause additional browser redirects to your TYPO3 sites
> index page. Overall potentially causing an infinite loop. Now when
> you set 'config.baseURL' you should also set 'prefixLocalAnchors',
> this stops href anchors '#' from looking like www.domain.com.au/# and
> instead the anchor is prefixed with the 'page name' of the current
> requested page. The below ts code also demonstrates how to set
> 'config.baseURL' to work with https pages, i.e. when using extension
> 'https_enforcer'.
> Code to add to main ts template here, (inserted above 'page = PAGE'
> declaration).
> ------------------
>
> # turn on simulate static documents
> config.simulateStaticDocuments = 1
>
> ## Set <base href=...> , considers if website uses SSL/https pages
> ## remove single comments here when if website uses SSL/https pages
> #[globalVar = TSFE:page|tx_httpsenforcer_force_secure = 1]
> #config.baseURL = https://www.domain.com.au/
> #[else]
> config.baseURL = http://www.domain.com.au/
> #[global]
> config.prefixLocalAnchors = all
>
> page = PAGE
>
>
>
> -----------------------------------------------------------
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