How to select multiple items from a reference field dropdown in Sanity?

i tried this but didn't work{
title: 'Category',
name: 'categories,
type: 'array',
of: [
{
type: 'reference',
to: [
{type: 'category'},

]
}
]
},

This above works but when i do :inputComponent: conditionalFields,
            options:{

              condition: (document, parent) => parent.articleType != "shortStories"
             },
it does not work it gives blank can anyone help me.

Yes, I am using the conditionalField package to hide that field when articleType=="shortStories". When i use conditionalField i am getting this above error but when i remove the conditionalField it works perfect.

Yes, I am using the conditionalField package to hide that field when articleType=="shortStories". When i use conditionalField i am getting this above error but when i remove the conditionalField it works perfect.

I am using conditionalField file.import PropTypes from "prop-types";
import React from "react";
import * as PathUtils from '@sanity/util/paths'
import { FormBuilderInput, withDocument, withValuePath } from "part:@sanity/form-builder";


/**
* ConditionalField input component will wrap any regular input field configured
* with

options.condition

in the schema. *
*

option.condition

should be a function that accepts two parameters,

document

* and

parent

, and returns

true

if the wrapped field should be shown. *
* Inspired by the following code examples:
* -
https://sanity-io-land.slack.com/archives/C9Z7RC3V1/p1583362492389300?thread_ts=1583335061.341000&cid=C9Z7RC3V1 * -
https://github.com/sanity-io/sanity-recipes/blob/master/snippets/conditionalFieldsCustomInputComponent.js */

class ConditionalField extends React.Component {

// Declare shape of React properties
static propTypes = {
type: PropTypes.shape({
title: PropTypes.string,
options: PropTypes.shape({
condition: PropTypes.func.isRequired
}).isRequired
}).isRequired,
level: PropTypes.number,
focusPath: PropTypes.array,
onFocus: PropTypes.func.isRequired,
onChange: PropTypes.func.isRequired,
onBlur: PropTypes.func.isRequired
};

// Reference to input element
_inputElement = React.createRef();

// Called by the Sanity form-builder when this input should receive focus
focus() {
if (this._inputElement.current) {
this._inputElement.current.focus();
}
}

// Renders the form input if condition function returns true
render() {
const { document, getValuePath, value, level, focusPath, onFocus, onBlur, onChange } = this.props;

// Extract type without 'inputComponent' (self reference) to avoid infinite loop
const { inputComponent, ...type } = this.props.type;

// Find the active field's parent object in the document
const parentPath = getValuePath().slice(0, -1); // <- Remove current field from path
const parent = PathUtils.get(document, parentPath);

// Condition to evaluate if component should be shown, defaults to true
const defaultCondition = () => false;
const condition = (type.options && type.options.condition) || defaultCondition;

if (!condition(document, parent)) {

// Hide component
return null;

/**
* ----------------------------------------------------------------
* QUESTION
* How can we also delete the field value from the stored document?
* Running patch unset seems inefficient if it unsets the field
* every time the Studio UI is rendered, even though the stored
* document has not changed, but might be an acceptable solution.
* ----------------------------------------------------------------
*/

} else {

// Render component
return (
<div>
<FormBuilderInput
level={level}
ref={this._inputElement}
type={type}
value={value}
onChange={onChange}
path={[]}
// focusPath={focusPath}
onFocus={onFocus}
onBlur={onBlur}
/>
</div>
);

}

}

}

export default withValuePath(withDocument(ConditionalField));

When i use this in category it does not refer to category i guess so and adds empty item.

One thing that may help: we recently released conditional fields within out of the box Studios. If you upgrade your studio, you can take advantage of this and simplify your schema.

How to upgrade the studio how to use it

You can upgrade the studio using

sanity upgrade

and the link in the reply above will take you through the usage!

{ name: "articleType",
type: "string",
title: "Select Article Type",
initialValue:"Text",
options: {

list: [
{ title: "Text", value: "Text" },
{ title: "Audio", value: "audio" },
{ title: "Video", value: "video" },
{title:"Habit Cards", value:"cards"},
{title:"Short Stories", value:"shortStories"},
],
},
},
{
title: 'Categories',
name: 'categories',
type: 'array',
of: [
{
type: 'reference',
to: [
{type: 'category'},
]
}
],
hidden: ({ parent, value }) => parent.articleType==="shortStories",
},
I am doing this it does not display the category field in any condition can you please help.I want to hide when the articleType=="shortStories" how can i achieve that

It worked for me on restarting server! How can i restricted that selecting reference doesn't get duplicated? like same category name cannot be selected multiple times.

Also want to add on how can i do conditional validation like when this field is not hidden i want it to be required.

Also want to add on how can i do conditional validation like when this field is not hidden i want it to be required.