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Internet Explorer oddity when referencing strings in Javascript

I came across an interesting quirk about Internet Explorer the other day.  A customer of ours said they were having trouble with a certain page of our application.  After some investigation, I narrowed it down to these lines of code:

var firstWhen = "09:12 PM"; // Added this beginning variable for simplicity
var timeParts = firstWhen.split(" ");
var amPm = timeParts[1];
var timePart = timeParts[0];
var hourAndMinute = timePart.split(":");
var hour = hourAndMinute[0];
if (hour[0] == "0")
hour = hour[1];
var minute = hourAndMinute[1];
if ( >= 0)
hour = parseInt(hour) + 12;
if (hour == 24)
hour = 12;
if (hour == 12)
hour = 0;

This snippet of code converts a string of time from standard 12-hour format to military or 24 hour format. Seems simple enough and it works on all non-IE browsers (Chrome, Firefox and Safari).

The problem here is actually two parts. First, the IF statement starting with if (hour[0] == "0") should look at the first character of “hour” and if its the char “0”, then set hour to just the second character. Basically strip the “0” if its there. I’m not sure if this is a proper way to reference a string as an array of characters (this is actually not my code, but a co-workers), but it works on all modern browsers. And it makes sense in my head. But, of course, Internet Explorer doesn’t like it. So IE7 and IE8 skip this line and always return hour as “09” (in this example).

Now on to the second offending bit of code. The line hour = parseInt(hour) + 12; works only if hour does NOT start with a zero. If it does start with a zero, parseInt() assumes an octal value. So when IE returns “09” in this example, parseInt(“09”) returns null (09 is not a whole octal number). And hour gets set to 12 instead of 21 breaking the conversion.

So I implemented two code fixes here. First replace the IF statement with:

if (hour.charAt(0) == "0")
hour = hour.charAt(1);

This gets rid of the IE oddity. The second part is to pass the radix value to parseInt() since I am always in base 10:

hour = parseInt(hour, 10) + 12;

The second part isn’t necessary to fix the IE part, but its a good safeguard. It also makes the code a bit more readable.

It took me half a day to find this offending code, so I thought I would jog it down.

NOTE: I’m new to WordPress and the standard code formatting is terrible. Hopefully I can find a nice add-on to help. So I apologize for the bad spacing for now…


Creating Java’s XMLGregorianCalendar in Coldfusion or Railo

Today I needed to access a web service method that required an XMLGregorianCalendar object.  And I found out it’s not as easy as it should have been.  I couldn’t find anything from a quick google search, which led me to start a blog.  Most of the time when I come across programming questions or roadblocks, a quick google search usually finds a solution.  But this time not so much.  I figured this was as good time as any to give a little back to the internet.

So the way that I consume the web services created for our GuestAssist application is by calling a Jar file created from a WSDL.  The reason we use this method is because Railo has a bug in which it won’t consume SOAP web services that return complex objects (kind of annoying).  Regardless, to call one of the web services functions, I needed to pass in a java XMLGregorianCalendar.  Here’s an example of how I was able to create the java variable in Coldfusion and pass it to the web service:

// Create a DTO object required to pass back to the web service
MyDTO = CreateObject("java", "");

// First save a java GregorianCalendar object
gc = CreateObject("java", "java.util.GregorianCalendar");

// Now create a java DatatypeFactory object
df = CreateObject("java", "javax.xml.datatype.DatatypeFactory");

// Instantiate the DataFactory object

// And finally call the java method newXMLGregorianCalendar and pass the GregorianCalendar object

// Finally set the required date on the DTO object