Deprecated

hjsonschema

JSON Schema library

https://github.com/seagreen/hjsonschema

Version on this page:0.10.0.2
LTS Haskell 11.22:1.7.2
Stackage Nightly 2018-03-12:1.7.2
Latest on Hackage:1.10.0@rev:1

See all snapshots hjsonschema appears in

MIT licensed by Ian Grant Jeffries
Maintained by [email protected]
This version can be pinned in stack with:hjsonschema-0.10.0.2@sha256:21e064089bc3ad9abbbfc9793bc12e8a18f4523f2992c226b99411fd735c7a7a,5042

Module documentation for 0.10.0.2

hjsonschema logo

A Haskell implementation of the current JSON Schema specification (Draft 4).

Hackage / GitHub / Travis CI

NOTE: You CANNOT use untrusted JSON data to make schemas. Schemas with circular references can cause infinite loops. See the issue list for more info.

Example

See here.

Tests

Run all tests:

stack test

Run only local tests:

stack test hjsonschema:local

Run remote tests (makes GETs to json-schema.org, also temporarily starts an HTTP server on port 1234):

stack test hjsonschema:remote

Details

Goals

  • Be a correct and fast implementation of the spec.

  • Be a useful reference for implementers in other languages. Haskell’s high level nature, expressive type system and referential transparency suit this purpose well.

Good Parts

  • Passes all the tests in the language agnostic test suite.

  • Very modular, which should make it easy to support future versions of the specification.

Bad Parts

  • Uses the pcre-heavy regular expression library for the “pattern” validator. It should use a library based on the ECMA 262 regex dialect, which the spec requires.

Notes

  • JSON-Schema-Test-Suite is vendored from commit # aabcb3427745ade7a0b4d49ff016ad7eda8b898b here.

  • src/draft4.json is from commit # cc8ec81ce0abe2385ebd6c2a6f2d6deb646f874a here.

Credits

TJ Weigel created the logo.

Tim Baumann wrote aeson-schema, on which hjsonschema’s test code and its implementation of SchemaGraph were based.

Julian Berman maintains the fantastic language agnostic test suite.

Changes

# 0.10.0.1

+ Fix .cabal file.

# 0.10

+ Rewrite fetching internals.
+ Fix reference resolution defects, add more tests.
+ Switch to a Perl style regex library, which is closer to ECMAScript regexes
than the previous Posix style one.
+ Add one-step validation functions ('fetchFilesystemAndValidate' and 'fetchHTTPAndValidate').
+ Alias the validation failure type exported by 'Data.JsonSchema.Draft4' to
'Invalid', change its field names.

# 0.9

+ Partial rewrite. The API of the library has changed, see the examples
folder for how to use the new one.

+ Users of the library can now write schemas in Haskell as well as JSON.

# 0.8

+ Improve scope updating and resolving.
+ Rename RawSchema's _rsObject field to _rsData.
+ Make RawSchema's _rsURI field a Maybe. This way schemas without a starting
URI can say so explicitly with Nothing instead of with "".
+ Rename Graph to SchemaGraph. Declare it with data instead of type. Give it a
field referencing the starting schema. This field is used to find the curent
schema if no URI is in scope and a self-referencing $ref is found (e.g. "#").
+ Change the order of the last two arguments to fetchReferencedSchemas.

# 0.7.1

+ Support GHC 7.8 again.

# 0.7

Change error type from Text to ValidationFailure.

Revert the 0.6 changes to validate. Also switch from Vector
to list. Validate is now:
Schema err -> Value -> [ValidationFailure err]

Add fetchReferencedSchemas', which lets the user provide their
own MonadIO function to be used when fetching schemas. This lets
them do things like only fetch schemas from particular domains.

# 0.6

Break the API so the library doesn't induce boolean blindness.

Change validate
was: Schema -> Value -> Vector ValErr
now: Schema -> Value -> Either (Vector ValErr) Value

Change Schema
was: type Schema = Vector Validator
now: newtype Schema = Schema { _unSchema :: [Validator] }

# 0.5.3

+ Switch from http-conduit to http-client.

# 0.5.2

+ Add convenience function for validating and compiling draft 4 schemas
simultaneously.

# 0.5.1

+ Switch from wreq to http-conduit; drop lens dependency.

# 0.5

+ Start changelog.
+ Rename Utils.hs to Helpers.hs.
+ Move all non-ValidatorGen functions in Validators.hs to Helpers.hs.
+ Various touchups.