Searches through a list of filters and finds a specific predicate that should be appended at the top level of a search (i.e., has special requirements for combining with other predicates). Also verifies that the predicate is not combined in any invalid ways.

Combination Requirements:

  • Only ONE filter can have a predicate with the target field
  • Only ONE predicate with the target field can exist
  • The predicate can only be ANDed to other predicates
  • The predicate's field value MUST be a string or boolean (not string[] or IMatchOptions)

Example: Portal's bbox field cannot be conditionally searched. Any value provided will always be applied as a top-level filter.

  • Valid: ?bbox=1,2,3,4&filter=type:CSV
  • Invalid: `?filter=type:CSV OR (type:PDF AND bbox=1,2,3,4)


Parameter Type Default Notes
field Required string

the field of the desired predicate

filters Required IFilter[]

filters to be searched / validated


the predicate (if present and all requirements are met)

Property Type Notes

Function defined in common/src/search/_internal/commonHelpers/getTopLevelPredicate.ts:22