Source

File: wp-includes/pluggable.php

function get_avatar( $id_or_email, $size = 96, $default = '', $alt = '', $args = null ) {
		$defaults = array(
			// get_avatar_data() args.
			'size'          => 96,
			'height'        => null,
			'width'         => null,
			'default'       => get_option( 'avatar_default', 'mystery' ),
			'force_default' => false,
			'rating'        => get_option( 'avatar_rating' ),
			'scheme'        => null,
			'alt'           => '',
			'class'         => null,
			'force_display' => false,
			'loading'       => null,
			'extra_attr'    => '',
		);

		if ( wp_lazy_loading_enabled( 'img', 'get_avatar' ) ) {
			$defaults['loading'] = 'lazy';
		}

		if ( empty( $args ) ) {
			$args = array();
		}

		$args['size']    = (int) $size;
		$args['default'] = $default;
		$args['alt']     = $alt;

		$args = wp_parse_args( $args, $defaults );

		if ( empty( $args['height'] ) ) {
			$args['height'] = $args['size'];
		}
		if ( empty( $args['width'] ) ) {
			$args['width'] = $args['size'];
		}

		if ( is_object( $id_or_email ) && isset( $id_or_email->comment_ID ) ) {
			$id_or_email = get_comment( $id_or_email );
		}

		/**
		 * Allows the HTML for a user's avatar to be returned early.
		 *
		 * Passing a non-null value will effectively short-circuit get_avatar(), passing
		 * the value through the {@see 'get_avatar'} filter and returning early.
		 *
		 * @since 4.2.0
		 *
		 * @param string|null $avatar      HTML for the user's avatar. Default null.
		 * @param mixed       $id_or_email The avatar to retrieve. Accepts a user_id, Gravatar MD5 hash,
		 *                                 user email, WP_User object, WP_Post object, or WP_Comment object.
		 * @param array       $args        Arguments passed to get_avatar_url(), after processing.
		 */
		$avatar = apply_filters( 'pre_get_avatar', null, $id_or_email, $args );

		if ( ! is_null( $avatar ) ) {
			/** This filter is documented in wp-includes/pluggable.php */
			return apply_filters( 'get_avatar', $avatar, $id_or_email, $args['size'], $args['default'], $args['alt'], $args );
		}

		if ( ! $args['force_display'] && ! get_option( 'show_avatars' ) ) {
			return false;
		}

		$url2x = get_avatar_url( $id_or_email, array_merge( $args, array( 'size' => $args['size'] * 2 ) ) );

		$args = get_avatar_data( $id_or_email, $args );

		$url = $args['url'];

		if ( ! $url || is_wp_error( $url ) ) {
			return false;
		}

		$class = array( 'avatar', 'avatar-' . (int) $args['size'], 'photo' );

		if ( ! $args['found_avatar'] || $args['force_default'] ) {
			$class[] = 'avatar-default';
		}

		if ( $args['class'] ) {
			if ( is_array( $args['class'] ) ) {
				$class = array_merge( $class, $args['class'] );
			} else {
				$class[] = $args['class'];
			}
		}

		// Add `loading` attribute.
		$extra_attr = $args['extra_attr'];
		$loading    = $args['loading'];

		if ( in_array( $loading, array( 'lazy', 'eager' ), true ) && ! preg_match( '/\bloading\s*=/', $extra_attr ) ) {
			if ( ! empty( $extra_attr ) ) {
				$extra_attr .= ' ';
			}

			$extra_attr .= "loading='{$loading}'";
		}

		$avatar = sprintf(
			"<img alt='%s' src='%s' srcset='%s' class='%s' height='%d' width='%d' %s/>",
			esc_attr( $args['alt'] ),
			esc_url( $url ),
			esc_url( $url2x ) . ' 2x',
			esc_attr( join( ' ', $class ) ),
			(int) $args['height'],
			(int) $args['width'],
			$extra_attr
		);

		/**
		 * Filters the HTML for a user's avatar.
		 *
		 * @since 2.5.0
		 * @since 4.2.0 The `$args` parameter was added.
		 *
		 * @param string $avatar      HTML for the user's avatar.
		 * @param mixed  $id_or_email The avatar to retrieve. Accepts a user_id, Gravatar MD5 hash,
		 *                            user email, WP_User object, WP_Post object, or WP_Comment object.
		 * @param int    $size        Square avatar width and height in pixels to retrieve.
		 * @param string $default     URL for the default image or a default type. Accepts '404', 'retro', 'monsterid',
		 *                            'wavatar', 'indenticon', 'mystery', 'mm', 'mysteryman', 'blank', or 'gravatar_default'.
		 *                            Default is the value of the 'avatar_default' option, with a fallback of 'mystery'.
		 * @param string $alt         Alternative text to use in the avatar image tag. Default empty.
		 * @param array  $args        Arguments passed to get_avatar_data(), after processing.
		 */
		return apply_filters( 'get_avatar', $avatar, $id_or_email, $args['size'], $args['default'], $args['alt'], $args );
	}