Search, Filtering & Faceting

Overview

OpenRegister provides a comprehensive, backend-agnostic search and filtering system for register objects. The system supports full-text search with relevance ranking, field-level filtering with comparison operators, faceted drill-down navigation, multi-field sorting, and cursor/offset pagination. A single unified API surface (ObjectService.searchObjectsPaginated()) operates transparently against PostgreSQL, Apache Solr, or Elasticsearch.

Tender demand: 78% of analyzed government tenders require advanced search and filtering capabilities.

Full-Text Search

Triggered via the _search query parameter:

• Searches across all type: string properties in the schema's dynamic table
• Always includes metadata fields: _name, _description, _summary
• Case-insensitive matching via ILIKE in the database backend
• String properties with format: date, format: date-time, or format: time are excluded from text search
• PostgreSQL pg_trgm extension enables fuzzy matching when installed
• Solr and Elasticsearch backends use their native query parsers

GET /api/objects/meldingen-register/meldingen?_search=geluidsoverlast

Field-Level Filtering

Any schema property can be used as a filter parameter with comparison operators:

Operator suffix	Description	Example
(none)	Exact match	?status=actief
[like]	Pattern match (SQL LIKE)	?title[like]=overlast%
[>=]	Greater than or equal	?prioriteit[>=]=3
[<=]	Less than or equal	?aanmaakdatum[<=]=2026-01-01
[>]	Greater than	?score[>]=7.5
[<]	Less than	?score[<]=3.0
[!=]	Not equal	?status[!=]=gesloten
[in]	In list (comma-separated)	?status[in]=nieuw,in_behandeling
[nin]	Not in list	?status[nin]=gesloten,afgehandeld
[exists]	Field exists/has value	?locatie[exists]=true

System metadata fields (_name, _uuid, _owner, _created, _updated, _deleted, _schema, _register) are always available as filter targets regardless of schema.

Faceting

Facets provide aggregated counts per distinct value — enabling "drill-down" navigation in UIs.

Enabling Facets

Facets are configured per schema property:

{
  "properties": {
    "status": {
      "type": "string",
      "facetable": true
    },
    "publicatiedatum": {
      "type": "string",
      "format": "date",
      "facetable": {
        "aggregated": false,
        "title": "Publication Date",
        "type": "date_histogram",
        "options": { "interval": "year" }
      }
    }
  }
}

Facet Types

Type	Description
terms	Distinct value counts (default for string/enum properties)
date_histogram	Bucketed counts by interval (day, month, quarter, year)
date_range	Pre-defined date range buckets
range	Numeric range buckets

Facet Computation

• Facets are computed on the full filtered dataset, independent of pagination — so facet counts always reflect the entire result set, not just the current page
• aggregated: true merges counts across schemas in a cross-schema query
• aggregated: false keeps facets per-schema (default for date histogram)
• Boolean facetable: true is backward-compatible shorthand for { "aggregated": true }
• Facet results are cached at multiple layers: in-memory, APCu/distributed, and database-persistent for sub-200ms response times on large datasets

Requesting Facets

GET /api/objects/meldingen-register/meldingen?_facets=status,publicatiedatum

Response includes both the paginated object list and a facets key with aggregation results.

Sorting

GET /api/objects/meldingen-register/meldingen?_order[aanmaakdatum]=desc&_order[titel]=asc

Multiple sort fields are supported. Metadata fields (_created, _updated, _name) are always sortable.

Pagination

Two pagination modes:

Mode	Parameter	Description
Offset	?_start=0&_limit=25	Classic page-based; efficient for small result sets
Cursor	?_after=<cursor>	Stable cursor for large result sets or infinite scroll

Default page size is 25. Maximum page size is configurable per register.

Search Backends

Backend	Full-Text	Fuzzy	Facets	Notes
PostgreSQL	ILIKE	pg_trgm (optional)	SQL GROUP BY	Default; no additional setup
Apache Solr	Native query parser	Trigram/phonetic	Native faceting	Higher performance for large datasets
Elasticsearch	Native query parser	Fuzzy queries	Aggregations	Best for complex faceting

The backend is selected per register via the Source configuration. The SearchBackendInterface ensures all backends expose the same query API.

Cross-Schema Search

Objects across all schemas in a register (or across all registers) can be searched in a single query:

GET /api/objects?_search=vergunning&_register=omgevingsdienst-register

Cross-schema facets with aggregated: true merge value counts across schemas.

Saved Views

Named saved searches can be stored as View objects, allowing frequently-used filter combinations to be bookmarked and shared:

POST /api/views
{
  "name": "Openstaande meldingen",
  "register": "meldingen-register",
  "schema": "meldingen",
  "filters": { "status": "nieuw", "_order[aanmaakdatum]": "desc" }
}

API

GET /api/objects/{register}/{schema}    Search objects with any combination of parameters
GET /api/objects/{register}             Cross-schema search within a register
GET /api/objects                        Cross-register search (global)
GET /api/views                          List saved views
POST /api/views                         Create a saved view
GET /api/views/{id}                     Execute a saved view

Related Features

• Registers & Schemas — facet configuration lives on schema properties
• Object Storage & Lifecycle — objects being searched
• Access Control (RBAC) — RBAC filters are applied transparently to all searches
• OpenAPI & GraphQL APIs — GraphQL queries support equivalent filtering