Working with Drupal 7.58 and File Entity 2.19 and Rules 2.10
First I needed to fire a rule when saving a new file and I found a solution (here).
Now I would like to fire a rule when an user removes an image (file) from a content (Image field with multiple values).
I can not find any event to start working after an image is removed?
EDIT 1 :
Following @Pierre.Vriens "check list approach", I have tried to create a simple rule fired when an image is removed :
{ "rules_verify_pictures_removed" : {
"LABEL" : "Verify pictures removed",
"PLUGIN" : "reaction rule",
"OWNER" : "rules",
"TAGS" : [ "image" ],
"REQUIRES" : [ "rules_conditional", "rules" ],
"ON" : { "node_update--article" : { "bundle" : "article" } },
"DO" : [
{ "LOOP" : {
"USING" : { "list" : [ "node-unchanged:field-pictures" ] },
"ITEM" : { "list_item" : "Previous list item" },
"DO" : [
{ "CONDITIONAL" : [
{
"IF" : { "NOT list_contains" : { "list" : [ "node:field-pictures" ], "item" : [ "list-item" ] } },
"DO" : [
{ "drupal_message" : { "message" : "Picture has been removed.", "type" : "warning" } }
]
}
]
}
]
}
}
]
}
}
Unfortunately, condition is always False and I get the message even if no item has been removed (One message for each item, unchanged, added or removed)