I was wondering if there are any best practice web sites on using PHP on Google App Engine.
While working through installing the Joomla! CMS on GAE I've run into some weird oddities and initially have taken a rather brute force approach to work through them. Being unhappy with the brute force method[which requires modifying core files in the open source code in order to accommodate GAE] I have continued to cycle on it in the back burner and am trying an alternate approach right now. Specifically, in Joomla there are 3 main entree points to an application: http://mydomain.com/index.php http://mydomain.com/administrator/index.php http://mydomain.com/installation/index.php So far I've run into 2 issues: 1) Joomla uses XML files in order to define html form's. PHP is used to parse those files and then build the forms. GAE disables the ability to load /remote/ XML files in PHP by default. It is possible to allow this by add libxml_disable_entity_loader to the list of enabled functions and then to call libxml_disable_entity_loader(false); at some point in the code. For some reason, despite the fact that these are LOCAL xml files Jooma attempts to read, I still need to use this fix to allow Joomla to read the local files. 2) Joomla defaults to saving sessions in files, GAE defaults to saving sessions in memcache. Attempt to save session files using the default save_path does not work since the path does not exist. Making a small hack to make memcache the default does not work because Joomla checks for the existence of the Memcache extension[via extension_loaded()] which does not exist in GAE. A slightly more involved solution required me adding a new GaeMemcache class to override that check, and modifying a core class to force it to enable GaeMemcache. None of this is bad...it's just inelegant and messy. It strikes me that this was the wrong way to go about it. Because of the way GAE is configured through app.yaml to match URI patterns to individual php files - instead of changing the core code, I can instead provide a pre-loader to process the file. So my new file structure will be as follows: /gae/joomla-site.php /gae/joomla-install.php /gae/joomla-admin.php /gae/lib/gaememcache.php /gae/appl.yaml /joomla-cms : submodule git repository pointer for the Joomla-CMS repository With this layout, I can now define my 3 entree points so that instead of loading the various index.php files directly, I can proxy the call first by the /gae/joomla* php file. That gives me the ability to make any Google App Engine modifications needed[defining a special memcache handler for GAE, making my libxml_disable_entity_loader function call - etc. No core hacks needed - now I can just setup a special pre-processors to handle everything. The configuration ability of GAE is extremely fascinating.. In many ways it is overly cumbersome for simply usage due to the options available - but the options also allow for neat little workarounds[I also realized that instead of hacking the core file, I could have made a copy of the core file under my gae directory and used the upload path overrides to overwrite the core files only when uploaded/deployed to GAE] What I am somewhat curious about is if there are any best practices tutorials out there since this sort of situation seems like it should be common, and the various answers are intuitive once you start groking the GAE deployment system. -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-appengine+unsubscr...@googlegroups.com. To post to this group, send email to google-appengine@googlegroups.com. Visit this group at http://groups.google.com/group/google-appengine. For more options, visit https://groups.google.com/groups/opt_out.
