Sunday, June 16, 2019

APEX custom Theme Style performance

When you create an application in Oracle Application Express (APEX) using the Universal Theme, the application comes with a few default "Theme Styles" which are essentially various stylesheets that you can switch between to go from the default blue (called "Vita") to, for example, the dark grey style (called "Vita - Slate").

You can use the Theme Roller in Oracle Application Express (APEX) to customize the colors and other settings, and by saving these you create your own Theme Styles. In this video, Shakeeb from the Oracle APEX team demonstrates how to use the Theme Roller, and he also briefly mentions that the generated stylesheet for custom theme styles can be placed into the filesystem for better performance.

I recorded a video myself to discuss the details of how custom Theme Styles affect the performance of your APEX application, and how you can move the Theme Style generated stylesheets to a web server to maximize performance and minimize bandwidth consumption:

Another issue that I did not mention in the video is that when you pick an icon for your application, APEX creates an app-icon.svg file (for the logo itself) and app-icon.css (that references the svg file), and places both those files in your Static Application Files.

Now since these files (and all other Static Application Files) are stored in the database, they require a database hit to retrieve, instead of fetching them from (and caching them on) the web server filesystem.

So if you want to maximize performance, I suggest that you remove the reference to the logo CSS file from your application (and delete the files from the Static Application Files).

If you really want that logo icon, you could of course place the .svg and .css files on the web server and reference them from there instead.

Thursday, April 25, 2019

Thoth Gateway version 1.4.3 now available

I've updated the Thoth Gateway (a PL/SQL web gateway similar to mod_plsql and ORDS, but written in .NET that allows you to run APEX and PL/SQL Web Toolkit applications using Microsoft IIS web server).

The latest release is version 1.4.3. It fixes a few minor issues, but more importantly it is compiled against the latest ODP.NET Managed Driver.

Among other things, this version of the Managed Driver supports Oracle Advanced Security Option (ASO) encryption; without this certain operations such as APEX file uploads would cause "OracleInternal.Network.NetworkException: ORA-12537: Network Session: End of file" errors against an Oracle 18c database.

When upgrading to Thoth Gateway v1.4.3 or later, please make sure you also copy the Oracle.ManagedDataAccess.dll file in addition to the PLSQLGatewayModule.dll file to make sure you have the correct library.


Wednesday, January 30, 2019

APEX Plugin: Execute PL/SQL code and return content to page (updated)

Oracle APEX has a built-in Dynamic Action called "Execute PL/SQL Code" that executes a block of PL/SQL code on the server via an Ajax call (ie does not do a regular submit and reload of the whole page).

But what if you want to do something on the server AND also return some content back to the client? Back in 2012 I released an APEX Dynamic Action plugin called "Execute PL/SQL Code and Return Content" that allows you to do just that. Read the original blog post for more information.

Since then, the APEX framework has evolved and the old Ajax workhorse function called "htmldb_Get" has been deprecated and replaced with functions in the "apex.server" namespace. Hence I have updated my plugin to use the modern API.

You can find the updated version (1.1) of the plugin on my GitHub page for APEX plugins. Note that the new plugin has been exported from APEX 18.1 and therefore requires at least that version to import and use.

Enjoy! :-)