project-pan

A Clojure library for validating xAPI Profiles, according to the xAPI Profile specification.

Installation

Add the following to the :deps map in your deps.edn file:

com.yetanalytics/project-pan {:mvn/version "0.5.0"
                              :exclusions [org.clojure/clojure
                                           org.clojure/clojurescript]}

Usage

To use the library to validate a whole Profile, call validate-profile in the pan namespace. This method takes in an entire Profile as an EDN data structure and prints either a success message on success (obviously) or an error message on failure.

Similarly, to validate a collection of Profiles, call validate-profile-coll on them. Each Profile in the collection will be able to reference Concepts, Templates, and Patterns from the other Profiles.

Arguments may be supplied for different levels of validation strictness, which are listed as follows:

• :syntax? - Basic validation; check only the types of properties and simple syntax of all Profile objects. Default true.
• :ids? - Validate the correctness of all object and versioning IDs (the id and inScheme properties). Validate that all IDs are distinct and that all inScheme values correspond to valid Profile version IDs. If multiple Profiles are involved, all IDs are checked that they are distinct among all Profiles (not just the Profile it is a part of).*
• :multi-version? - A flag for the :ids? keyword arg; if false then ID validation will check that all objects have the same inScheme value. If true, then in addition to the usual ID checking, validation that Template and Pattern IDs change when their properties (other than inScheme, prefLabel, and scopeNote) change is active. Default false.
• :relations? - Validate that all relations between Profile objects are valid. These relations are given by IRIs and include the following:
  • the broader, narrower, related, broadMatch, narrowMatch, relatedMatch and exactMatch properties for Verbs, Activity Types and Attachment Usage Types.
  • the recommendedActivityTypes property for Activity Extensions
  • the recommendedVerbs property for Context and Result Extensions
  • Determining Properties, objectStatementRefTemplate property and the contextStatementRefTemplate properties for Statement Templates.
  • sequence, alternates, optional, oneOrMore and zeroOrMore properties for Patterns.
• :concept-rels?, :template-rels?, :pattern-rels? - Similar to :relations?, except that each only validates relations specific to Concept, Statement Template, and Pattern properties, respectively. Each are default false, and are overridden when :relations? are true.
• :contexts? - Validate that all instances of @context resolve to valid JSON-LD contexts and that they allow all properties to expand out to absolute IRIs during JSON-LD processing. The @context property is always found in the Profile metadata and in Activity Definitions, though they can also be found in Extensions for said Activity Definitions.

Other keyword arguments include:

• :external-profiles - Extra Profiles from which to reference Concepts, Statement Templates, and Patterns from. Unlike the Profiles passed into validate-profile-coll, these Profiles are not validated (though will be treated as part of the same scope in terms of ID distinctiveness validation).
• :external-contexts - Extra @context values (other than the xAPI Profile and Activity contexts) that @context IRIs in profile can reference during context validation. During multi-profile validation, all Profiles refer to the same global :external-contexts map. Default {}.
• :result - This value affects the format of the result type.
  • :print prints an Expound-generated error string to standard output.
  • :string returns the aforementioned error string (or a vector of them, in the case of validate-profile-coll).
  • :type-string returns a {:type string} map, where :type is a keyword and string is an error message specific to that type of error. :type can be one of the following:
    • :syntax-errors for basic validation errors
    • :id-errors for ID errors
    • :in-scheme-errors for inScheme errors
    • :concept-edge-errors for errors between Concept relations
    • :template-edge-errors for errors between Template relations
    • :pattern-edge-errors for errors between Pattern relations
    • :pattern-cycle-errors for cycles in the Pattern relation graph
    • :context-errors for errors relating to JSON-LD context
  • :type-path-string returns a {:type {path string}} map, where path is the assoc-in vector needed to retrieve the erroneous value, and string is an error message specific to that error location.
  • :spec-error-data - Return a {:type spec-error-data} map, with each value being the map generated by Clojure spec. Default.
• :error-msg-opts - Takes an opt map that affects how error messages are formed and printed. Currently only takes :print-objects?, which when true (default) displays the entire object in error messages, and if false only displays IDs.

Additional API Functions

The validate-object function is provided in order to provide a way to validate individual Concepts, Templates, and Patterns without having to go deeper than the top level API. The :type and :result keyword args are used to fix the expected spec and to affect the function result, respectively; more details can be found in the docstring.

The get-external-iris function is provided in the API in order to retrieve IRI values that refer to external objects, JSON-LD contexts, etc. (i.e. objects that do not exist in the Profile). This allows the user to more easily retrieve external Profiles and contexts in their application from the Internet or their data store.

The json-profile->edn function is provided in the API to provide for convenient coercion of JSON profile strings into an EDN format that Pan recognizes.

Besides validating whole Profiles, you can also use library methods and specs to validate parts of Profiles, such as individual Concepts, Templates and Patterns).

TODO

• Be able to access external links:
  • Non-inline schema values are given by IRIs that link out to external JSON Schemas.
  • Except for the two w3id contexts given by the Profile spec, any and all @context values need to be given by external links.
• Log errors to somewhere instead of printing them out.
• More graceful exception handling.
• Any bugs that need to be fixed (natch).

License

Copyright © 2019-2022 Yet Analytics, Inc.

Project Pan is licensed under the Apache License, Version 2.0. See LICENSE for the full license text