@comunica/mediator-number

Comunica Number Mediator

A mediator that can mediate over a single number field. It can either choose the actor with the maximum or with the minimum value.

This module is part of the Comunica framework, and should only be used by developers that want to build their own query engine.

Click here if you just want to query with Comunica.

Install

$ yarn add @comunica/mediator-number

Configure

After installing, this mediator can be instantiated as follows:

{
  "@context": [
    ...
    "https://linkedsoftwaredependencies.org/bundles/npm/@comunica/mediator-number/^1.0.0/components/context.jsonld"  
  ],
  "actors": [
    ...
    {
      "@type": "SomeActor",
      "someMediator": {
        "@id": "config-sets:sparql-queryoperators.json#mediatorQueryOperation",
        "@type": "MediatorNumberMin",
        "cmn:Mediator/Number/field": "httpRequests",
        "ignoreErrors": true,
        "cc:Mediator/bus": { "@id": "cbqo:Bus/QueryOperation" }
      }
    }
  ]
}

Instead of MediatorNumberMin, MediatorNumberMax could also be used to resolve to the maximum value.

Config Parameters

• cc:Mediator/bus: Identifier of the bus to mediate over.
• cmn:Mediator/Number/field: The field name to mediate over.
• cmn:Mediator/Number/ignoreErrors: Optional flag to indicate if actors that throw test errors should be ignored, defaults to false.

Changelog

v1.22.0 - 2021-08-30

Added

• Add support for SPARQL extension functions
• Allow custom fetch function to be provided via context
• Support AbortControllers in native http actor
• Report FILTER errors as warnings in the logger, Closes #767
• Add SPARQL endpoint-based hypermedia update actor
• Allow resource creation via HTTP PUT:
  • Add RDF update hypermedia actor for LDP PUT destinations
  • Configure RDF update hypermedia actor for LDP PUT destinations
  • Allow RDF dereference actors to return on non-200 responses
  • Add metadata extractor for HTTP Accept-Put header
  • Add metadata extractor for HTTP Allow header

Changed

• Refactor CLI arguments handling using yargs
• Optimize node-fetch HTTP actor and set as default
• Include response body in dereference errors
• Bump fetch-sparql-endpoint with improved error reporting for SPARQL endpoints
• Update dependency htmlparser2 to v7 (#851)
• Migrate to @rdfjs/types
• Bump to sparqlalgebrajs 3
• Notify downstream clients on worker timeout
• Bump fetch-sparql-endpoint with AbortControllers
• Make HTTP accept headers deterministic
• Add URL-based heuristic to determine SPARQL endpoints to top-level actor

Fixed

• Update to AsyncIterator 3.2.0 to fix memory issue
• Fix http proxy not working with immutable node-fetch response
• Fix invalid hash implementation for hash-join
• Fix node-fetch actor not supporting body.cancel
• Do not reset sparql.js blank-node counter (Closes #836)
• Fix SPARQL-based update actors not being able to handle quads

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