Merge Field Functions in Email Templates

This may help to get people thinking about how much can be accomplished with text and HTML email templates before diving into Visualforce templates.

Did you know that you can substitute in text for blank values? By using the {!sObject.FieldName, substitute text including spaces} convention, blank values can be automatically replaced with default values.

Furthermore, it looks like at the email templates recognize at least two Visualforce-esque functions, demonstrated in the following examples:

• {!NullValue(Lead.Name,"visitor")}, which is the same as the substitution described above
• {!If(Lead.Name="Barack Obama","President","Citizen")}
• {!If(IsPickVal(Lead.Status,"New"),"Super Important","Somewhat Important")}
  

Does anyone have any other information on what functions can be used in simple text or HTML email templates? Are all Visualforce functions available here, I wonder?

Bug (?) with ISNULL() Function in Validation Rules

I tried to setup a simple validation rule today in my sandbox to enforce the presence of a value in a Lookup field.

My first attempt for the error formula was:
ISNULL( Source_Program__c )

However, this turned out not to work at all. Whether a value was in the field or not, the formula never generated a validation error.

Then, I switched over to an even more basic formula:
Source_Program__c = null

This worked like a charm. Am I missing something here?

ISBLANK(String) Returning false When String.length() Returns 0

I discovered this with version 21.0 of the Salesforce API: When a String's length is 0, the ISBLANK(String) Visualforce function will actually return false instead of true.

Visualforce Developer's Guide, Version 21.0 describes the ISBLANK function as follows:

Determines if an expression has a value and returns TRUE if it does not. If it contains a value, this function returns FALSE.

A search for ISNULL in the documentation returned no real results, which makes me wonder if ISNULL has been unofficially deprecated in favor of ISBLANK.

So, it appears that the only way to know for sure whether a String input has been blanked out is to use the length method and compare it to 0.