Remove punctuation from string using Javascript

I’m a morning person, and my mind is usually sharpest on Monday or Tuesday mornings, so these are the best times for me to work on fiddly javascript stuff. Today was one of those mornings and here are the results, just in case I want to refer back to them later on.

I had many items dotted around an Apex application where the user is allowed to enter “Codes” – values that must be uppercase and contain no spaces or other punctuation characters – except underscores (_) were allowed.

To make things easier for the user, I wanted the page to automatically strip these characters out when they exit the field, instead of just giving validation errors (Note: I still included the validations, but the javascript just makes the process a bit smoother for the user doing the data entry).

My APEX application already has a global .js file that is loaded with each page, so all I had to do was add the following code to it:

function cleanCode (c) {
  return c.replace(/[^A-Za-z0-9_]/g,"");
}

$(document).ready(function() {

  //automatically remove non-code characters from
  //"edit_code" class
  $( document ).on('change', '.edit_code', function(){
    var i = "#"+$(this).attr("id");
    $(i).val( cleanCode($(i).val()) );
  });

});

EDIT: greatly simplified regexp based on the excellent contribution by Jacopo 🙂
EDIT #2: corrected, thanks to Sentinel

Finally, on each “Code” page item, I set the following attribute (or append, if other classes have already been added):

HTML Form Element CSS Classes = edit_code

For code items within a tabular form, I set the following column attribute:

Element CSS Classes = edit_code

Calculate Age in Javascript

I had a registration form in Apex which asks the applicant to enter their Date of Birth in a date item; I then needed to calculate how old they would be at the start of the event, which determines a number of rules, such as whether we need to obtain their parent’s permission.

In my first release I implemented this with a Dynamic Action which ran SQL something like this:

select round(months_between(start_date
                           ,to_date(:P1_DATE_OF_BIRTH,'DD-MON-YYYY'))
             / 12,1)
from events
where event_id = :P1_EVENT_ID;

This worked fine – it takes advantage of Oracle’s builtin support for date arithmetic. However, it was rather slow, because it needs to do a roundtrip to the database to run the query and return the result.

I wanted a pure javascript implementation to avoid the roundtrip, but my initial searches came up with a number of sub-par solutions involving extracting the year and month portions and applying simple arithmetic which did not take into account leap years.

Instead, I’ve gone with an easier solution taking advantage of the moments javascript package.

1. Add the path to moment.min.js in the File URLs attribute of the page. You could get your own local copy or point to the relevant file from a cdn: http://cdnjs.com/libraries/moment.js/
2. Add a function to the Function and Global Variable Declaration attribute of the page, which uses the moments object to convert the strings into date objects, and then call the diff method to get the number of years as a floating-point number, e.g.:

   function getAge() {
     var e = moment($v("P1_EVENT_DATE"),"YYYYMMDD")
        ,dob = moment($v("P1_DATE_OF_BIRTH"),"DD-MMM-YYYY");
     return e.diff(dob,'years',true).toFixed(1);
   }

3. Add a Dynamic Action to the Date of Birth item which calls getAge() and sets the value of the Age display item.

The result is a much quicker response and less load on the database. This is an intentionally simple example, you could do it in different ways to suit your situation (e.g. if you have multiple date items you need to handle on the same page, you might pass them as parameters to the function).

The moments javascript package has an impressive list of features, including pretty-formatting a duration (e.g. a client-side version of the SINCE format e.g. “3 years ago”) documented here.