Skip to main content

Reusable Module Components in APEX

When building a serious application you often need to repeat certain regions in a couple of pages, for instance customer or order information. In APEX you can ofcourse copy a region to another page, but that enhances your maintenance effort when changes are needed on this copied region. Another solution is to group all the pages that share this region in one application and define the region on the famous Page 0. But maybe there is a more elegant way to solve this....

As an example I use the 'My Favorite Tasks' region I described in the previous post. First we set the page alias to 'MYFAV', to circumvent a static reference to a page number. In the region header of 'My Favorite Tasks' we set a HTML tag '<snap>' and '</snap>' in the footer (this <snap> is just an example, it can be anything, as long as it isn't a regular HTML tag). Now define a new HTML region on the page where you need to 'reference' this 'My Favorite Tasks' region and set the region source to <div id='Favorites'></div>. Now we created a placeholder for future use...

Now let's fill this placeholder with the contents of the 'My Favorite Tasks' region.
Set the Page HMTL Body Attribute to : onload="ShowFavs();". This will fire a javascript function when the page is loaded. You probably have to set the value of 'Cursor Focus' to 'Do not focus cursor' otherwise you'll get a 'You may not declaratively set cursor focus' error. Next define the javascript function in the HTML Header section.

<script type="text/javascript">
function ShowFavs(){
var get = new htmldb_Get(null,$v('pFlowId'),null,'MYFAV');
gReturn = get.get(null,'<snap>','</snap>');
get = null;

This function will request the 'MYFAV' page. Then the page is 'stripped' so only the HTML between the tags is returned. And this HTML is rendered in the placeholder...

So with this simple and elegant solution you can define 'region building blocks' (even more meaningful than 'My Favorite Tasks') and assemble pages using this building blocks! So re usability increases and your maintenance effort decreases.

In a next post I will show how you even can put regions anywhere on a page without defining a placeholder at all...

Popular posts from this blog

Showing a success message after closing a modal dialog

APEX 5 comes with Modal Dialogs out of the box. Very neat. Especially for adding and changing data. And to minimise the number of time a user has to click, it could be useful to add a "Close Dialog" process after the actual data processing. When the data processing fails, the Dialog stays on top showing the error. When data processing runs fine, the Dialog is closed ... without any confirmation. And this might be scary for a shaky user.

So how can we provide the user some feedback? On Page 4 of the Sample Dialog Application you can see one solution: up on a Dialog Closed Event on the parent page it does a redirect to refresh the parent page appending the success message of the "Close Dialog" process. This has two drawbacks. First, it probably refreshes more than necessary. And second, if you're using multiple layers of dialogs (dialogs that open other dialogs) the message appears in the "parent dialog".
As an alternative you could follow these steps: 1…

APEX 5 New Static File Features

In APEX 4 you could upload files - like CSS files, JavaScript files, Images and whatever else you like - into the APEX Repository. When you navigate to Shared Components, there is a Files section that offers three different options:
CSS Files are always uploaded (and changed !) for the whole Workspace. For Images and Static Files (usually JavaScript) you could choose whether they should be available for the whole Workspace or for a specific Application only. And if you had a lot of files - e.g. a lot of images - then you had to go through the upload process one-by-one. But that's usually a one time only thing. If you make changes to the CSS and JavaScript files - and that's a continuous process in development - then you had to delete the existing file and upload the new one. Over and over again. And meanwhile fighting the cache of the webserver and your browser.  And another irritating issue: You couldn't use relative references in your CSS or JavaScript files as they just…

Using LDAP for Authentication and Authorization within APEX

One of my current customers would like to use their LDAP (Microsoft Active Directory) server for authentication and authorization of APEX applications. Of course we tried to set up a standard LDAP Authenication that's available within APEX. But we couldn't get that to work. Maybe it has to do with the fact that the client stored their Users within Groups within Groups within .... . Or maybe it doesn't do a full tree walk in the directory. Or maybe it is just because it is Microsoft - and not Oracle Internet Directory (OID). So we moved to a custom Authentication using the DBMS_LDAP functions (and some examples from the Pro Oracle Application Express book and Tim Hall - a.k.a. Oracle Base).

One of the issues we encountered that we wanted to use the user's login name, like "jdoe" and not his full name ("John Doe"). And the login name is stored in the "sAMAccountName" attribute. But authenticating using just "jdoe" didn't work. …