Using RegEx in JSON Schema

Question

Trying to write a JSON schema that uses RegEx to validate a value of an item.

Have an item named progBinaryName whose value should adhrere to this RegEx string "^[A-Za-z0-9 -_]+_Prog\\.(exe|EXE)$".

Can not find any tutorials or examples that actually explain the use of RegEx in a JSON schema.

Any help/info would be GREATLY appreciated!

Thanks, D

JSON SCHEMA

{
    "name": "string",
    "properties": {
        "progName": {
            "type": "string",
            "description": "Program Name",
            "required": true
        },
        "ID": {
            "type": "string",
            "description": "Identifier",
            "required": true
        },
        "progVer": {
            "type": "string",
            "description": "Version number",
            "required": true
        },
        "progBinaryName": {
            "type": "string",
            "description": "Actual name of binary",
            "patternProperties": {
                "progBinaryName": "^[A-Za-z0-9 -_]+_Prog\\.(exe|EXE)$"
            },
            "required": true
        }
    }
}

ERRORS:

Warning! Better check your JSON.

Instance is not a required type - http://json-schema.org/draft-03/hyper-schema#

---

Schema is valid JSON, but not a valid schema.

---

Validation results: failure

[ {
    "level" : "warning",
    "schema" : {
        "loadingURI" : "#",
        "pointer" : ""
    },
    "domain" : "syntax",
    "message" : "unknown keyword(s) found; ignored",
    "ignored" : [ "name" ]
}, {
    "level" : "error",
    "domain" : "syntax",
    "schema" : {
        "loadingURI" : "#",
        "pointer" : "/properties/ID"
    },
    "keyword" : "required",
    "message" : "value has incorrect type",
    "expected" : [ "array" ],
    "found" : "boolean"
}, {
    "level" : "error",
    "domain" : "syntax",
    "schema" : {
        "loadingURI" : "#",
        "pointer" : "/properties/progBinaryName"
    },
    "keyword" : "required",
    "message" : "value has incorrect type",
    "expected" : [ "array" ],
    "found" : "boolean"
}, {
    "level" : "error",
    "schema" : {
        "loadingURI" : "#",
        "pointer" : "/properties/progBinaryName/patternProperties/progBinaryName"
    },
    "domain" : "syntax",
    "message" : "JSON value is not a JSON Schema: not an object",
    "found" : "string"
}, {
    "level" : "error",
    "domain" : "syntax",
    "schema" : {
        "loadingURI" : "#",
        "pointer" : "/properties/progName"
    },
    "keyword" : "required",
    "message" : "value has incorrect type",
    "expected" : [ "array" ],
    "found" : "boolean"
}, {
    "level" : "error",
    "domain" : "syntax",
    "schema" : {
        "loadingURI" : "#",
        "pointer" : "/properties/progVer"
    },
    "keyword" : "required",
    "message" : "value has incorrect type",
    "expected" : [ "array" ],
    "found" : "boolean"
} ]

---

Problem with schema#/properties/progBinaryName/patternProperties/progBinaryName : Instance is not a required type
Reported by http://json-schema.org/draft-03/hyper-schema#
Attribute "type" (["object"])

Solution 1

To test a string value (not a property name) against a RegEx, you should use the "pattern" keyword:

{
    "type": "object",
    "properties": {
        "progBinaryName": {
            "type": "string",
            "pattern": "^[A-Za-z0-9 -_]+_Prog\\.(exe|EXE)$"
        }
    }
}

P.S. - if you want the pattern to match the key for the property (not the value), then you should use "patternProperties" (it's like "properties", but the key is a RegEx).

Solution 2

Your JSON schema syntax is incorrect. Change

"patternProperties": {
    "progBinaryName": "^[A-Za-z0-9 -_]+_Prog\\.(exe|EXE)$"
    }

to

"patternProperties": {
    "^[A-Za-z0-9 -_]+_Prog\\.(exe|EXE)$": {}
    }

Comments

[Destroyer]

Thank you for providing an answer and not wasting my time. Much, much appreciated!

[cloudfeet]

Wasn't the question was about testing the value, not the property name?

[Ninja]

Is it possible to have case insensitive pattern matching?

[PsychoFish]

@Ninja it seems it can be done only via properly designed regular expression. Check json-schema.org/understanding-json-schema/reference/… - usage of flags is not within recommended RegExp syntax for JSON Schema due to interoperability reasons.

[rofrol]

@Ninja for cace insensitive look at stackoverflow.com/questions/41874810/…