Skip to main content

5 Cool Things you can do with HTML5 (p4)

The fourth part of this series of posts will cover Notifications. When you are a user of GMail and using Chrome, you probably are familiar with those little boxes that popup when you've got new mail. Those type of notifications you can create in your APEX application as well - using HTML5!
Alas, at this moment, these type of notifications only work in Chrome. In Firefox you can add this extension so it'll work in that browser as well. The other ones will follow - sooner or later...
You can also use this plugin that mimics this feature - to be safe on every platform, but that one will appear in your browser, so that's not a desktop notification.
But how do you create a real desktop notification?
As usual with HTML5, you just need a few lines of code. The code below is executed in a Dynamic Action when a button is pressed:

function RequestPermission (callback) {
window.webkitNotifications.requestPermission(callback);
}
function showNotification(){
if (window.webkitNotifications){
  if (window.webkitNotifications.checkPermission() > 0) {
  RequestPermission(showNotification);
  }
  else {
  window.webkitNotifications.createNotification(
  "#APP_IMAGES#HTML5.jpg", //Put link to your icon here
  "Notification",
  "Now you are notified!").show();
  }
 }
else
{ alert('Sorry, you have to switch to another browser to use notifications - or use the other button ;-)');
}
}
//Run:
showNotification();


Just like geoLocations, the browser has to ask the user for permission to use Desktop Notifications (for a domain). Once the permission has been granted you can call the "show()" method, containing an image, the title and the actual message. Easy and cool, huh!

And you can even get completely wild by creating notifications that contain HTML or adding event listeners to your notifications - for instance doing something when the notification is closed. See this for some more examples.

See the working APEX example on : http://apex.oracle.com/pls/apex/f?p=22115:NOTIFICATIONS.

Comments

fateh.cis said…
Hello,
Can you please, make your app available for us to download for better understanding ...

Another thing, on the link you referenced - for more examples - there is plus sign on the right hand that we can use to scroll down to specific section on the page. How can we apply this on APEX to scroll down into specific region on the page..

Best Regards,
Fateh
fateh.cis said…
Thanks a lot for making your examples app available for us...
Can we use this notification to send a notification to a specific apex user ??

Best Regards,
Fateh
Roel said…
@Fateh: Using some creativity, you can...
Imagine you create a table with a TO_USER and MESSAGE column. Then you can conditionally load a region containing with the notification on Page 0 - so when the user refreshes or changes the page he gets the notification.
If you want to send a user a notification even without a refresh/pagechange, you should check out Websockets....

HTH
Roel

Popular posts from this blog

Fix Interactive Report headers issue when using a Region Display Selector

When you have multiple Interactive Reports (IR) on your page and use a Region Display Selector to mimic tabs, you might notice some weird behaviour in the IR headings if you switch tabs. The headings are not positioned correctly and you get an extra empty row under the headings. It just looks weird and ugly. But if you resize your browser window, it all looks fine again (until you switch to another tab..) So can we fix this by creating a Dynamic Action that mimics that "browser window resize" event? Yes we can! Create a Dynamic Action that fires on Click of the jQuery selector li.apex-rds-item a . That should fire a JavaScript snippet :  apex.event.trigger(this.triggeringElement, "apexwindowresized"); So now a click on a tab not only switches from one IR to another but also fires that event that will "autofix" the IR headers. A simple solution for an annoying problem. This applies to APEX 5.0, I assume it will be solved in 5.1.

How to create neatly formatted Excel documents using PL/SQL?

If there is a requirement to produce output from an application into Excel, you would probably create a CSV (Comma Separated File) with the data and start Excel to show the data - at least that's what I did...until now. The drawback of this solution is that you could only produce data and no nice layout. But Excel is also capable of opening HTML-files and using this you could create Excel files with data and magnificent layout! Let me give an example: 1. Create a procedure to show the data in formatted in an HTML table. CREATE OR REPLACE PROCEDURE display_emp_list IS v_emp_count NUMBER(5); v_empno NUMBER(8); v_ename VARCHAR2(50); v_job emp.job%TYPE; v_sal emp.sal%TYPE; v_bg_color VARCHAR2(10) := ''; CURSOR c_emp IS SELECT empno, initcap(ename), job, sal FROM emp ORDER BY ename; BEGIN SELECT COUNT(*) INTO v_emp_count FROM emp; owa_util.mime_header('application/ms-excel', FALSE); htp.p('Content...

Refresh selected row(s) in an Interactive Grid

In my previous post I blogged about pushing changed rows from the dabatase into an Interactive Grid . The use case I'll cover right here is probably more common - and therefore more useful! Until we had the IG, we showed the data in a report (Interactive or Classic). Changes to the data where made by popping up a form page, making changes, saving and refreshing the report upon closing the dialog. Or by clicking an icon / button / link in your report that makes some changes to the data (like changing a status) and ... refresh the report.  That all works fine, but the downsides are: The whole dataset is returned from the server to the client - again and again. And if your pagination size is large, that does lead to more and more network traffic, more interpretation by the browser and more waiting time for the end user. The "current record" might be out of focus after the refresh, especially by larger pagination sizes, as the first rows will be shown. Or (even wors...