Set the value of a metadata field.

Param1 $resource The ID of the resource.
Param2 $field The numeric ID or shortname of the field.
Param3 $value The value to set the field to.
Can be a comma separated list for fixed list option fields. Use double quotes to enclose strings and use backslash as the escape character.
NOTE If passing option (node) IDs ensure that the next parameter $nodevalues is set to TRUE
Param4 $nodevalues Set to TRUE if passing in values as a comma separated list of field option IDs retrieved via get_field_options().

Return values

The operation success (true/false).