4th December 2024 at 9:00am
| purpose | select one of each group of input titles by field |
|---|---|
| input | a selection of titles |
| suffix | optionally, list-item or value |
| parameter | F=the name of a field, defaulting to title |
| output | a selection containing the first input title encountered for each distinct value of field F |
Learn more about how to use Filters
Each input title is processed in turn. The value of field F in the corresponding tiddler is examined.
- each
- As long as the value of the field is unique (i.e. has not been encountered before), the title is appended to the output.
- each:list-item
- The value is treated as a title list. Each title in the list considered in turn. If it has not been encountered before, it is appended to the output.
- each:value
- As long as the title is unique it is appended to the output whether or not the corresponding tiddler exists.
Note that if a tiddler does not contain field F, it is treated as if the value of the field were empty. Thus, a filter expression such as [each[motovun]] will return one tiddler that doesn't have a motovun field, as well as one tiddler with each distinct value of that field, if any. To obtain just the tiddlers that have a non-blank value for the motovun field one can use [each[motovun]has[motovun]].