## Use `IF..Then..Else` [new in Draft-07][1] 




<pre><code>{
 "$schema": "http://json-schema.org/draft-07/schema#",
 "type": "array",
 "items": {
 "type": "object",
 "properties": {
 "controlType": {
 "type": "string",
 "enum": ["title", "dropdown", "button"]
 },
 "options:": {
 "type": "array",
 "items": {"type": "string"}
 }
 },
 
 "if": {
 "properties": {
 "controlType": {"const": "dropdown"}
 }
 },
 "then": {
 "required": ["options"]
 }
 }
}
</code></pre>


## Use [`oneOf`][6] or [`anyOf`][5]

This can be useful if you have a property that has a limited number of acceptable values (such as an enum), but each possible value needs to be individually mapped. 




<pre><code>{
 "$schema": "http://json-schema.org/draft-07/schema#",
 "type": "array",
 "items": {
 "type": "object",
 "properties": {
 "controlType": {
 "type": "string",
 "enum": ["title", "dropdown", "button"]
 },
 "options:": {
 "type": "array",
 "items": {"type": "string"}
 }
 }, 
 "anyOf": [
 {
 "properties": {
 "controlType": {"const": "dropdown"}
 },
 "required": ["controlType", "options"]
 },
 {
 "properties": {
 "controlType": {"const": "title"}
 },
 "required": ["controlType"]
 },
 {
 "properties": {
 "controlType": {"const": "button"}
 },
 "required": ["controlType"]
 }
 ]
 }
}
</code></pre>


### Further Reading

* [Conditionally require attribute][2]
* [Applying subschemas conditionally][3]
* [Combining schemas][4]





[1]: http://json-schema.org/draft-07/json-schema-release-notes.html
[2]: https://stackoverflow.com/a/38781027/1366033
[3]: https://json-schema.org/understanding-json-schema/reference/conditionals.html
[4]: https://json-schema.org/understanding-json-schema/reference/combining.html
[5]: https://json-schema.org/understanding-json-schema/reference/combining.html#anyof
[6]: https://json-schema.org/understanding-json-schema/reference/combining.html#oneof

I'm building a json schema definition which has a fixed set of controls that I've currently limited with an `enum`. However, not all properties are relevant for all controls.  

I only want to require an `options` property if the `controlType` = `dropdown`

```js
{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "type": "array",
  "items": {
    "type": "object",
    "properties": {
      "controlType": {
        "type": "string",
        "enum": ["title", "dropdown", "button"]
      },
      "options:": {
        "type": "array",
        "items": {"type": "string"}
      }
    }
  }
}
```

How can I conditionally include / require a field in a json schema?

Properties based on enum value in JSON Schema

In VS Code, there are several tags which trigger autocompletion and validation for local file path references. For example, when entering an img tag:


[![Path autocomplete][1]][1]


I have a json file which stores the metadata for an image grid, and I'd like to try to add a validation that the image path is typed in correctly. For example, here's an a json file that contains items with image paths and other metadata:

**images.json**

```js
[
 {
 "color": "red",
 "path": "./images/kitten.jpeg" /* identify value type as local path */
 },
 /* ... more items ...*/
]
```

And here's a [JSON Schema Definition][2] which has been [applied to the vs workplace settings][3]:


**.vscode/settings.json**

```js
{
 "json.schemas": [
 {
 "fileMatch": [
 "/images.json"
 ],
 "schema": {
 "$schema": "http://json-schema.org/draft-07/schema#",
 "type": "array",
 "items": [
 {
 "type": "object",
 "properties": {
 "color": {"type": "string", "enum": ["blue", "red", "green"]},
 "path": {"type": "string", /* what to put here */},
 }
 },
 ]
 }
 }
 ]
}
```

Is there any way to check local file paths using [JSON Schema Validation][4] or some alternative way to tell VS Code that a particular field is representing local file references?


 [1]: https://i.stack.imgur.com/HTBsA.png
 [2]: http://json-schema.org/draft-04/json-schema-core.html
 [3]: https://code.visualstudio.com/docs/languages/json#_json-schemas-and-settings
 [4]: https://json-schema.org/latest/json-schema-validation.html