Optional parameters for components

i don't think that's possible yet. sounds like a feature request

Tagging

It's already possible, but it's not yet exposed to the UI.

If I can't do it through the UI, can I use a hook or something to do it in a module? My plan is
to package my rule up with Features, so adding custom code isn't a big deal, once I know what I need to modify.

Just add the "optional => TRUE" flag to the variable in your rule / json export.

Would love to see it in the UI as well

Tried to export / import my rule adding the tag like that :

"USES VARIABLES" : {
"mission" : { "label" : "Mission", "type" : "text", "optional => TRUE" },

Got an error message saying that the pasted code cannot be analyzed.

Tried this instead :

"USES VARIABLES" : {
"mission" : { "label" : "Mission", "type" : "text", "optional" : "true" },

Import went well but the parameter does not seem to be considered as optional because I still get the message

2.559 ms The variable or parameter mission is empty.
3.458 ms Unable to evaluate action ...

What did I do wrong ?

Looks like if I add "allow null" and "default value" as suggested in this thread http://groups.drupal.org/node/233883

"USES VARIABLES" : {
"mission" : { "label" : "Mission", "type" : "text", "optional" : "true", "allow null" : "true", "default value" : "null" },

then it works. Now I have other errors but this seem to work

Switching back to feature request to have it in the UI

My modifications are gone as soon as I save the rule again from the UI... I should have expected it... definitely need it in the UI!

Duplicate of #1704282: Add "required" (allow null/empty) option to component parameters