Use Ajax to fetch users for author control, or use Customize Object Selector

[westonruter]

If there are a lot of users on a site, the time to generate the full author list upon initial customizer load will not be insignificant. This data should be lazy-loaded once it is needed (i.e. once an author control is visible) or better we should use Customize Object Selector once xwp/wp-customize-object-selector#13 is implemented.

See relevant code:

wp-customize-posts/php/class-wp-customize-posts.php

Lines 461 to 485 in bf1941a

	/**
	* Get the author choices array.
	*
	* @return array
	*/
	public function get_author_choices() {
	$choices = array();
	$query_args = array(
	'orderby' => 'display_name',
	'who' => 'authors',
	'fields' => array( 'ID', 'user_login', 'display_name' ),
	);
	$users = get_users( $query_args );
	if ( ! empty( $users ) ) {
	foreach ( (array) $users as $user ) {
	$choices[] = array(
	'value' => (int) $user->ID,
	'text' => esc_html( sprintf( _x( '%1$s (%2$s)', 'user dropdown', 'customize-posts' ), $user->display_name, $user->user_login ) ),
	);
	}
	}
	return $choices;
	}

wp-customize-posts/js/customize-post-section.js

Lines 622 to 668 in bf1941a

	/**
	* Add post author control.
	*
	* @returns {wp.customize.Control} Added control.
	*/
	addAuthorControl: function() {
	var section = this, control, setting = api( section.id ), postTypeObj, previousValidate;
	postTypeObj = api.Posts.data.postTypes[ section.params.post_type ];
	control = new api.controlConstructor.dynamic( section.id + '[post_author]', {
	params: {
	section: section.id,
	priority: 70,
	label: postTypeObj.labels.author_field ? postTypeObj.labels.author_field : api.Posts.data.l10n.fieldAuthorLabel,
	active: true,
	settings: {
	'default': setting.id
	},
	field_type: 'select',
	setting_property: 'post_author',
	choices: api.Posts.data.authorChoices
	}
	} );
	// Ensure selected author is integer, and not a string of digits.
	previousValidate = setting.validate;
	setting.validate = function ensurePostAuthorInteger( inputData ) {
	var data = _.clone( inputData );
	data = previousValidate.call( this, data );
	data.post_author = parseInt( data.post_author, 10 );
	return data;
	};
	// Override preview trying to de-activate control not present in preview context. See WP Trac #37270.
	control.active.validate = function() {
	return true;
	};
	// Register.
	section.postFieldControls.post_author = control;
	api.control.add( control.id, control );
	if ( control.notifications ) {
	control.notifications.add = section.addPostFieldControlNotification;
	control.notifications.setting_property = control.params.setting_property;
	}
	return control;
	},