Asides

Comparing .NET values

When comparing .NET variables, including Enums, you cannot use C/AL comparison operators. To compare .NET variables, you must use the Equals method (of the System.Object type) that all .NET types implement or inherit. So, instead of IF var1 = var2, or IF var1 = var1.EnumValue (in case of an Enum), just write IF var1.Equals(var2), or IF var1.Equals(var1.EnumValue).

I see this mistake often being made or attempted by developers, even though it has been documented inside .NET Interoperability documentation since it was introduced with 2009 R2.

Careful with Microsoft.Dynamics.NAV JavaScript object

Make sure that you don’t access the Microsoft.Dynamics.NAV JavaScript object before the document ready event fires. If you do so, you might experience problems on Chrome when the user refreshes the browser (F5). It appears that on refresh Chrome loads (and runs) scripts in different order, and depending on how complex scripts included in your project are, your code might get executed before Microsoft’s script is loaded, and it will cause nasty script errors. This occurs only on Chrome on PC.

Formatting for XML

When you have to format C/AL variables (numbers, dates/times, booleans) for exchange with other apps, call FORMAT(variable,0,9) instead of simply FORMAT(variable). The format 9 formats the variable according to XML standards, and this value can then be interpreted correctly on any system with any regional settings. This is useful also when passing string-formatted values from C/AL to C# or JavaScript.

Do you have a value, Mr. BLOB?

To check if a BLOB field has a value, you call its HASVALUE function. For example: IF Item.Picture.HASVALUE THEN;

In older versions, earlier than NAV 2009, you had to call CALCFIELDS before you could check HASVALUE, which – if you think of it, did not make much sense. This was changed in NAV 2009, so ever since that version you can check HASVALUE before you decide to call CALCFIELDS first. It makes all the sense – you don’t need to pull up to 2GB of data over just to see if anything is inside.

If you are an old-school guy (or just old, as me), and you CALCFIELDS first, HASVALUE next, maybe it’s time for you to reconsider it.

Rembember – the pattern is: IF Field.HASVALUE THEN Rec.CALCFIELDS(Field);