topic Re: Expressions not defined in Talend Studio

Expressions not defined

Anonymous — Sat, 16 Nov 2024 13:09:42 GMT

I am trying to use some of the build-in functions in the expression builder. Several functions give an error saying that the method is not defined:
An example of this is the LEFT function:
The method LEFT(String, int) is undefined for the type TalendJavaSourceViewer31

In the Expression Builder (in a tMap), I have:
LEFT(row1.FirstName,50)

Re: Expressions not defined

Anonymous — Mon, 03 Jan 2011 03:14:36 GMT

You need to refer to the function as

StringHandling.LEFT(row1.FirstName, 50)

LEFT is a static method defined in the StringHandling class.
Regards,
Abhi

Re: Expressions not defined

Anonymous — Mon, 03 Jan 2011 16:37:50 GMT

Ok. Tried that, and still getting an error. The syntax is now correct in the tMap expression, but when I run the full job I get:
Exception in component tMap_1
java.lang.NullPointerException
at routines.StringHandling.LEFT(StringHandling.java:209)

The code in my tMap expression is:
StringHandling.LEFT(row1.FirstName,50)

Re: Expressions not defined

Anonymous — Mon, 03 Jan 2011 18:05:08 GMT

I think you are getting "null" value for row1.FirstName. While making a call to StringHandling.LEFT, we need to ensure that row1.FirstName is not null. The following expression will evalute to null if row1.FirstName is null, else it will return the first 50 characters of row1.FirstName (or row1.FirstName itself, if length of row1.FirstName is less than 50).

row1.FirstName != null ? StringHandling.LEFT(row1.FirstName, 50) :
null

Re: Expressions not defined

Anonymous — Mon, 03 Jan 2011 18:16:45 GMT

That was the answer. Thanks!

Re: Expressions not defined

alevy — Mon, 03 Jan 2011 23:48:31 GMT

All StringHandling methods will be null friendly in v4.0.4 and v4.1.2 (see https://community.talend.com/t5/Archive/resolved-tMysqlInput-1-NB-LINE/td-p/176131).