Friday, 26 September 2008

Web Cache Compression and MOD_GZIP

Some of my colleagues are working on a project where bandwidth is massively limited (64k). One suggestion to increase application response time was to use MOD_GZIP (an open source compressor extension to Apache) to compress the outbound HTTP traffic. The only drawback is that MOD_GZIP is not supported by Oracle.

Since we are using Oracle Application Server, Web Cache achieves exactly the same by simply adding a compression rule to Web Cache for the URL Regular Expression /pls/apex/.*$

We noticed that without any compression of the HTTP outbound traffic, our test page took 30 seconds to fully render on a 64k link. Turning on compression reduced the rendering time to 7 seconds. Very impressive.

Navigating through an application with compression turned on was noticeably quicker than one without compression.

To test if your outbound HTTP traffic is compressed, I would grab the Live HTTP Headers extension to Firefox and you are looking for a line like: Content-Encoding: gzip in the outbound response.

I configured both APEX and Discoverer Viewer to use compression by following the metalink article: 452837.1

Thursday, 24 July 2008

Reset the APEX internal password

I noticed in one of the comments of Dimitri Gielis articles that Jornica pointed out a script called apxXEpwd.sql

I ran this as the SYS user and sure enough, it allows you to reset the ADMIN password for the internal workspace.

This script can be found in the root apex directory that you download from OTN.

Very useful when you forget what that password is!

Monday, 14 July 2008

Import APEX application via SQL Developer

I will be honest and admit that I have not been SQL Developers biggest fan since it's release a few years ago. Having always used 3rd party products such as TOAD and PL/SQL Developer, I found certain things a little irritating and not overwhelmingly obvious when forced to use SQL Developer.

Recently however, I found an absolute god send of a feature in SQL Developer and that was the ability to import / export APEX applications. This means that the Web GUI for such actions is no longer required.

Very simply, you connect to your parsing schema's database account via SQL Developer, right click on the Application Express tree directory and select Import Application. This opens a simple wizard and off you go.

One other cool feature of this is that you can open the details window and see exactly what your import is doing, something that is not possible when using the web GUI.

Download SQL Developer from: OTN

Tuesday, 10 June 2008

APEX 3.1.1 Released

Just upgraded from APEX 3.1 to 3.1.1 on an Oracle Enterpise Linux 4 Update 4 platform.

Intall took: 5:39 and termintaed without error.

The patch can be downloaded from metalink (patch number 7032837)

All in all, a very simple upgrade and now onto the task of regression testing our current 3.1 apps

Tuesday, 29 April 2008

Hide Show Regions on an Apex Page

One of the really nice features of APEX is the ability to hide / show regions when editing item or page attributes. This is really useful if you have to update the same attribute for multiple items.

If you want to implement this type of approach on a page you simply need to:

Create a New Region Template

Either create a new region template (or copy an existing one) and add a DIV tag with the id="XXX#REGION_STATIC_ID#" around the Definition Template.

Don’t forget to close the DIV at the end of the template. In this example I copied our region called “Reports Region” and named it “Reports Region 680 Width (Static ID)”

Add the following JavaScript to your Page Header: view

Create several regions on your page and assign a unique Static ID i.e. REGION1, REGION2 etc. Set the Region Template to the one you created in the 1.

Create a button for each Region you defined in the previous stage and add the following JavaScript call as the URL target of each button:

javascript:hideDiv(‘XXXREGION1’); // For the button called Region 1
javascript:hideDiv(‘XXXREGION2’); // For the button called Region 2
javascript:hideDiv(‘ALL’); // For the button called Show All

Create a hidden item on the page called CURRENT_DIV

Finally edit the page attributes and place the following command in the “Page HTML Body Attributes” section:


And that’s it. The key thing to note here is that once a region is hidden, all form items are still active in the DOM and will be submitted along with all the visible form items. This is a great way to break out long, complex forms and enhance the user experience.

An exmaple can be seen here

Monday, 21 April 2008

Tab Order of Elements on an APEX Page

To set the TAB order of your form, you simply need to add the attribute: TABINDEX="1" to the "HTML Form Element Attributes" of your items replacing the number with the desired sequence.

This is a great way of enhancing the usability of your forms.

Saturday, 19 April 2008

JavaScript API Documentation

I have just been reading the Apex 3.1 API documentation and noticed that the JavaScript API that are commonly used in Apex are now documented:

There is some very useful stuff in there!!

Friday, 28 March 2008

Multiple Interactive Reports on One Page

If you have been using Interactive Reports since Apex 3.1 landed, you are probably as impressed with them as I am.

The other day I tried to create more than 1 IR on a page and the Wizard prevented me saying "Only 1 Interactive Report can be declared on this page"

I then tired to copy a region that contained an Interactive Report and sure enough I suddenly had 2 IR's on the one page!

Whilst this is probably not supported or suggested, my requirement meant that only 1 IR was to be shown at once (i.e. I had a conditional diaply on both IR)

So if you need to create multiple IR's on the one page but will only display one at run time, copy of a region appears to work!