JSON Schema 'Required' validation set/removed by checkbox - jsonschema

Question

I am designing a web application modelled using JSON Schema. I am attempting to create a page with a text area and a checkbox. The text area is to explain why I like pizza. If the user clicks the check box, they are confirming they don't like pizza. The text box is 'required' unless the checkbox is selected. The checkbox is effectively operating as a boolean, but the components being used cannot be altered (because a user researcher said so). At the moment, I'm using AJV to validate my schema, and it is configured to throw errorMessages.required when a property is required but no input is entered/selected.
Unfortunately I'm completely inexperienced when it comes to JSON schema. Below is my current attempt to get this to validate. This renders correctly, but it doesn't work as I want - In my dev environment it just validates anything, yet on jsonschemavalidator.net it wont validate unless the checkbox is checked. How can my desired function be achieved?
{
$schema: 'http://json-schema.org/draft-07/schema#',
type: 'object',
additionalProperties: false,
propertyNames: {
enum: [
'q-why-i-love-pizza',
'q-i-hate-pizza'
]
},
properties: {
'q-why-i-love-pizza': {
type: 'string',
title: 'If you love pizza, tell us why',
maxLength: 500,
errorMessages: {
required: "Please tell us why you love pizza, or select 'I hate pizza'"
}
},
'q-i-hate-pizza': {
type: 'array',
maxItems: 1,
uniqueItems: true,
items: {
anyOf: [
{
title: 'I hate pizza',
const: 'hate'
}
]
},
errorMessages: {
required: "Please tell us why you love pizza, or select 'I hate pizza'"
}
}
},
allOf: [
{
$ref: '#/definitions/if-not-checked-then-q-why-i-love-pizza-is-required'
}
],
definitions: {
'if-not-checked-then-q-why-i-love-pizza-is-required': {
if: {
not: {
properties: {
'q-i-hate-pizza': {
const: 'hate'
}
}
}
},
then: {
required: ['q-why-i-love-pizza'],
propertyNames: {
enum: [
'q-i-hate-pizza',
'q-why-i-love-pizza'
]
}
}
}
}
}
EDIT:
I expect the following:
{
'q-why-i-love-pizza' : '',
'q-i-hate-pizza' : ['']
}
This should FAIL validation as no values have been selected.
{
'q-why-i-love-pizza' : 'I love pizza because it's amazing',
'q-i-hate-pizza' : ['']
}
This should PASS because the user has entered why they love pizza, so clicking the check box was not necessary.
{
'q-why-i-love-pizza' : '',
'q-i-hate-pizza' : ['hate']
}
This should PASS because although the user has not told us why they love pizza, they have checked the box to indicate they hate pizza.
{
'q-why-i-love-pizza' : 'I am a user, so decided to tell you I hate pizza too',
'q-i-hate-pizza' : ['hate']
}
This should also PASS because I need to accept the possibility that a user will tick the box to say they hate Pizza, but proceed to tell me anyway.
Solution:
{
type: "object",
properties: {
'q-why-i-love-pizza': {
type: 'string',
title: 'If you love pizza, tell us why',
maxLength: 500,
errorMessages: {
required: "Please tell us why you love pizza, or select 'I hate pizza'"
}
},
'q-i-hate-pizza': {
type: 'array',
maxItems: 1,
uniqueItems: true,
items: {
anyOf: [
{
title: 'I hate pizza',
const: 'hate'
}
]
},
errorMessages: {
required: "Please tell us why you love pizza, or select 'I hate pizza'"
}
}
},
allOf: [
{ $ref: "#/definitions/if-not-checked-then-q-offender-contact-description-is-required" }
],
definitions: {
"if-not-checked-then-q-offender-contact-description-is-required": {
if: {
not: {
required: ["q-i-hate-pizza"]
}
},
then: {
required: ["q-why-i-love-pizza"]
}
}
}
}

Answer 1

I've simplified your schema, so this might not be perfect, but this general approach should work.
{
"type": "object",
"properties": {
"q-why-i-love-pizza": { "type": "string", "maxLength": 500 },
"q-i-hate-pizza": { "const": ["hate"] }
},
"allOf": [
{ "$ref": "#/definitions/if-hates-pizza-then-q-why-i-love-pizza-is-required" }
],
"definitions": {
"if-hates-pizza-then-q-why-i-love-pizza-is-required": {
"if": { "not": { "required": ["q-i-hate-pizza"] } },
"then": { "required": ["q-why-i-love-pizza"] }
}
}
}

Answer 2

You're most of the way there, but you've missed something you may not have expected.
Your schema for if-not-checked-then-q-why-i-love-pizza-is-required.
The const keyword is only applicable to the property, IF it exists.
You need to add a required constraint to the if schema.
Obviously this is at a guess, as you haven't provided your JSON instance data.