[WordPress] A helper class to generate a HTML image string from a supplied image class, array or ID. Useful for dealing with images stored in custom fields.

cameronjonesweb-image-generator.php

<?php
// Helper class to generate responsive image HTML from an id or array
class cameronjonesweb_generate_image {

	public $output;

	function __construct( $image, $size = 'full' ) {

		if( is_array( $image ) ) {
			// It's an array
			if( isset( $image['ID'] ) ) {
				$this->output .= $this->compile_image( $image['ID'], $size );
			}
		} else if( is_object( $image ) ) {
			// It's a post object
			if( isset( $image->ID ) ) {
				$this->output .= $this->compile_image( $image->ID, $size );
			}
		} else {
			// We'll assume it's an ID
			$this->output .= $this->compile_image( $image, $size );
		} 

	}

	private function open_img() {
		return '<img ';
	}

	private function close_img() {
		return ' />';
	}

	private function get_src( $id, $size = 'full' ) {
		$src = wp_get_attachment_image_src( $id, $size );
		return ' src="' . $src[0] . '" width="' . $src[1] . '" height="' . $src[2] .'"';
	}

	private function get_alt( $id ) {
		$alt = get_post_meta( $id, '_wp_attachment_image_alt', true );
		$title = get_the_title( $id );
		return ' alt="' . ( !empty( $alt ) ? $alt : $title ) . '"';
	}

	private function get_class( $id ) {
		return ' class="wp-image-' . $id . '"';
	}

	private function compile_image( $id, $size ) {
		$id = intval( $id );
		return $id !== 0 ? wp_make_content_images_responsive( $this->open_img() . $this->get_src( $id, $size ) . $this->get_alt( $id ) . $this->get_class( $id ) . $this->close_img() ) : '';
	}

	public function return_image() {
		return !empty( $this->output ) ? $this->output : false;
	}

	public function display_image() {
		echo !empty( $this->output ) ? $this->output : false;
	}

}