Support for OGNL-expressions is currently under development for upcoming IDEA 11.
The goal is to support OGNL-expressions in S2-taglibs in the same way as for EL-expressions in JSPs.
not done yet
Basic syntax highlighting (identifiers, numbers, string literals, keywords, ..)
Escape sequences in strings
Highlight valid/invalid escape sequences
e.g. missing closing ")", missing expression
Highlight matching parentheses, brackets and braces
Color settings page
Settings->Editor->Colors & Fonts->OGNL
Customize the appearance (color, style) to your needs:
Auto-Insert closing quote/tick
Go To Declaration
Go To Code references
Navigate to Class/Method references.
Provide quick documentation on hovering over elements (type, name).
Expand selected part of expression semantically by repeatingly pressing CTRL-(Shift)-W:
Create your own OGNL-specific live templates (Context "OGNL") or use one of the predefined templates.
NOTE Expanding live templates in injected context does not seem to work currently, you have to open separate OGNL-fragment editor.
Complete expression, e.g. closing ")", "}"
Provide specific "Surround with.." functionality.
Provide basic whitespace-formatting settings, e.g. required space before/after operator.