Some months ago I published an Oracle Apex plugin to restrict the left side shuttle choices. You can read the original post here.
On the demo page the On Change event was used to refresh the left side list. My friend Alex Nuijten made the remark this was not very intuitive. The user needs to navigate out of the selection item to see the change.
So I changed the demo page to provide instant feedback. The selection is now refreshed after each keystroke. As this process is completely executed on the client the response is very fast. Only for very long list the user might notice a slight delay.
No changes to the plugin were needed. It can still be downloaded at apex.world

Here is how is was done:

Selection item
Name : P400_SELECTION
Type: Text Field

Dynamic Action
Name: Select on keystroke
Event: Key Release
Selection Type : Item
Item(s): P400_SELECTION

True Action
Name: Perform Selection
Action: Restrict Shuttle Values [plug-in]
Search Item: P400_SELECTION
Selection Type: Item(s)
Item(s): P400_SHUTTLE
Fire on initialization: No

Happy Apexing

Source Article from http://dickdral.blogspot.com/2017/07/restricting-shuttle-choices-even-faster.html

A few weeks ago I wrote a post how to avoid multiple logins when using a link in an email. This solution however does not work in a batch process for two reasons:

  • the URL needs to be fully specified, so protocol, server, port and directory are also needed. These data are not available outside the Apex context
  • the function apex_util.prepare_url can only be called from within an Apex session

My first idea was to prepare the URL for every possible mail while being in an Apex session and store it in the database. The stored URL can be used when generating the email.
This would be technically  complex, because a new column would have to be created and the content of this column would have to be kept up to date all the time.

Another possibility would be to create a fake Apex session within the batch process. Then the rest of the code need not be changed. Martin Giffy d’Souza provides a way to create an Apex session in this blogpost. Although this is an 5 year old post I was able to create an Apex session and generate a valid link.

The last solution was chosen because of the simplicity and the absence of need for code change.

Happy Apexing!

Source Article from http://dickdral.blogspot.com/2017/06/avoiding-multiple-logins-from-external_28.html

Some Apex applications sends notifications emails to users when tasks are due. These emails contain a link to an Apex page. When the user clicks on the link he is taken to the page. When this page is not public – which usually is the case – he is directed to the login page of the application. Even when he is logged in for the same browser on another tab.
When users get a lot of these emails it is annoying they have to log in each time. Apex provides a way to avoid the login when a session exists in the same browser. This post describes how you can set it up using the Rejoin Sessions functionality.

Source Article from http://dickdral.blogspot.com/2017/06/avoiding-multiple-logins-from-external.html

For the Apex Dashboard Competition of the DOAG in 2016 I created a Apex dashboard. You can read about it in this post
One of the elements of this dashboard was a group of four infocards.

These cards display the key values for a country on a certain subject. Apart from the text the cards differ in color and the icon used.
These cards are created using a named report template. This is a special kind of report template. Using a normal report template the query columns and rows map to the columns and rows in a HTML table. A named report template consists of a HTML template in which the query columns are referenced by name. For the infocards the query and template below are combined:

select 'Population'  title
     , population    data
     , 'Number of inhabitants'  text
     , 'fa-users'   as  icon_class
     , 'db2_red'     as  container_class
from   cnt

Row Template 1 within the Report Template:

The substitution strings in the template are replaced with the corresponding values from the query.
As you can see the column values can also be used to define CSS classes as in the enclosing DIV element. The value of the column container_class defines the name of the class to applied. This class defines the color of the card. The class icon_class defines the Font Awesome icon to be used.

The cards are styled with the following CSS:

The color of the card can be defined by selecting the db2_color class as container_class in the query. 

The icon is positioned absolute relative to the card with the class db2_icon_container. Space is created for the icon container by defining  left:80px; for the main DIV containing the text.

The rest is quite straight forward CSS styling.


You can create your own Named Report Template:
– navigate to Shared Components > Templates
– press Create
– chose Report
– create the template From Scratch
– enter the name for your template and check Named Column (row template)
– then enter the HTML for the template

Named Report Templates provides us developers with more freedom to style the output. The downside is that the templates are more specific and less widely applicable. 

Happy Apexing

Source Article from http://dickdral.blogspot.com/2017/04/displaying-info-cards-using-oracle-apex.html

The Oracle Apex shuttle item is a neat way to select a number of values. It is however not so user friendly when the list of choices is very long. In this case it is useful to be able to limit the list of choices.
When you implement the limitation in the LOV-query of the item, the limitation will also be applied to the selected values. Usually this is not the desired behavior.
This behavior is avoided when the restricting of the left shuttle pane using JavaScript. I have created a Dynamic Action plug-in to do this. The choices in the left shuttle pane are evaluated case insensitive against the content of the search item. If the search item contains more than one string ( separated by spaces) all the strings should occur in the shuttle value. The search string ‘INVOICE 2013’ returns only values that contain ‘INVOICE’ (independent of case) and ‘2013’.

The plugin attributes are the shuttle item and the select item. The plugin needs to know the select item to disable submit when enter is pressed.

You can see the plug-in in action on:

http://www.speech2form.com/ords/f?p=OPFG:RESTRICT_SHUTTLE

As usually you can find the plugin on apex.world

Happy apexing

Source Article from http://dickdral.blogspot.com/2017/04/oracle-apex-plug-in-for-restricting.html

Working with Apex I regularly write Javascript. Most of the time these client-side code snippet are blazing fast, but in some cases they take a few seconds to execute.

In these cases I want to see which part of the code is slow. In this process I use two very simple JS functions which make life a lot easier for me:

var timing_start;

function start_timing( text) {
    timing_start = performance.now();
    if ( text) { console.log('Start timing:'+text); } 
}

function show_timing(text)
{ console.log('Timing:'+text+', milliseconds:'+ (performance.now()-timing_start) );  }

You can put this code on the page or include it in a general JS file.

 The use of these functions is really simple:

start_timing();
...
code to be timed 
...
show_timing('Data retrieved');

This will result in the following output in the browser’s console:

Timing:Data retrieved, milliseconds:784.2350000000001

The show timing calls display the elapsed time since the last call to start_timing.

Happy JavaScripting

Source Article from http://dickdral.blogspot.com/2017/04/finding-slow-javascript.html

One of the things that cost me a lot of time is the writing of log statements.
I do it a lot when I am working on complex PL/SQL or JavaScript routines. Just to understand what’s happening. Mostly these log statements have the form:

logger.log(‘varname1=’||varname1||’, varname2=’||varname2, etc… );


and most of the time the variable names are even longer :-(. 
So it is a lot of typing, especially for something that is deleted after a few hours. As I am into automating my job I decided to automate it. Here you can see it in action: 




The selection and generation is all written in JavaScript. You can see how fast it works ( it is recorded in real time ). The code is pasted in the textarea, variables are selected by clicking and then the log statement(s) can be generated. 


You can find the page here:


http://www.speech2form.com/ords/f?p=OPFG:GEN_LOG_STMT


The page supports PL/SQL and JavaScript. For PL/SQL the identifier naming rules are quite strict, so these are implemented. At the moment the same rules are also applied to JavaScript. 
NB As JavaScript rules are very free, some variables might not be recognized, for example when they contain diacritics.


For PL/SQL you can select logger or apex_debug, for JavaScript console.log statements are generated. 
There is an option to generate mulitple calls or combine all variables in one call. 


I have tested this with PL/SQL and JavaScript and I could run the generated code as is, no changes were needed. 


Happy Apexing and JavasScripting

Source Article from http://dickdral.blogspot.com/2017/02/generate-log-statements-in-seconds.html

As my demo site grows I am curious about my visitors. Based on the Apex activity log I have created a report which shows the origin of the visitors:

The location is determined from the IP address. This is done in a Dynamic Action that calls a web service at ipapi.co to retrieve the geographical location from the IP address and then stores the result into an Oracle table for subsequent usage.

NB The apex_activity_log is limited in size and the older entries are regularly deleted. Therefore the content of the log is daily copied to a another table. This table is used for the report and the map.

I like to see that the visitors come from all over the world, not only from Europe, North America and Asia, but also from Middle and South America and Africa.
It is good to see that Apex is used all over the globe!

But the list does not give me an overview of the geographical locations. So I looked for a way to visualize this data and came across the GeoHeatMap plugin by Jeffrey Kemp. It is very easy to implement and just requires a query retrieving latitude, longitude and weight.

The result is a very nice looking map:

You can get a clear view of where the visitors come from.

In the normal mode the light green color is hardly visible against the predominantly green color of the maps. By setting the plugin attribute Map Style to mostly gray, found at  https://snazzymaps.com/style/4183/mostly-grayscale, you get the quiet background with sufficient contrast.

You can see the result at:

http://www.speech2form.com/ords/f?p=141:HEATMAP

It is possible to see the geographical distribution per page by changing the Page select list. There is clear difference in distribution for the various pages of the application.

Happy apexing

Source Article from http://dickdral.blogspot.com/2017/02/using-heatmap-plugin-to-monitor-site.html

Starting in Apex I used bind variables to reference the input items.


select name from table where id = :P100_ID

Then I move the query to a package and I had to rewrite the bind variables to calls of the Apex v function.

select name from table where id = v(‘P100_ID’)

For some queries I preferred to pass the parameters as PL/SQL procedure parameters so I had to change the query to:

select name from table where id = p_id


And for defining a ref cursor I prefer to use substitution parameters:

select name from table where id = [id]


Now this is just a short query with just one parameter.
But it is a lot of work for queries with  20+ lines with 5+ parameters.

And then it takes time to convert the parameters. And I make mistakes, I forget to change a parameter or I make a typo. Most of the time I find the error quite fast but sometimes it is not so obvious.

Enough reasons for me to automate this process. And make the solution publicly available:

http://www.speech2form.com/ords/f?p=OPFG:QUERY_VARIABLES

On the page you can paste your query. If possible the source parameter type is recognized.
You can indicate to what type of parameters are the target of the conversion.
Further you need to specify the delimiters for the substitution variables or the prefixes for PL/SQL and Apex ( for bind variables and v-function).

Then hit Generate, clip the code and use it.
For me most of the time I can use the code without modification.

Happy apexing…

Source Article from http://dickdral.blogspot.com/2017/01/utility-for-rewriting-query-parameters.html