WordPress As a Framework for Web Apps

In the past, WordPress has grown from a powerful blog system to a powerful CMS and, more recently, to a powerful framework for web applications. However, there are a lot of applications you shouldn’t build with WordPress. Using WordPress customization features and the WordPress API, there are not many applications you couldn’t make. Choosing which framework to use (or choose not to use one) is balancing between many pros and cons affecting architecture, performance, security, scalability, and so on.

WordPress is extremely useful as a base for medium-sized web apps without too much traffic. Building a small application, for example, a restaurant table booking system, from scratch or even with a framework like Rails or CakePHP would involve thinking about database schemes, controller structures, authentication, user interfaces, etc. WordPress is already doing a lot of this: you already have rough user management and a working admin interface, and you only have to think about how to map your data model to the existing WordPress database structure.

WordPress

Our use case: A recipe database

READ MORE :

I want to show you how to implement a simple recipe database with WordPress. Requirements are fundamental: Allows adding recipes and editing them just like ordinary posts or pages Allows categorizing recipes in hierarchical categories like Healthy -> Chicken -> Marinated Chicken Breasts Allows adding ingredients to a recipe and finding recipes by components Allows adding quantities to members of a formula, e.g., 500ml milk, 20g sugar, three tablespoons olive oil I will focus on how to customize WordPress to adjust it to your data model, mainly by showing you how to use the essentials to build every WordPress powered web app:

  • Custom post types
  • Custom taxonomies
  • Custom fields
  • Setup custom post type for recipes

In WordPress, the base of every content-holding entity is a post. The two post types you surely are familiar with are posts and pages. For our recipe database, we will create a new type: recipes.

  • register_post_type(‘recdb_recipe’,
  • array(
  • ‘labels’ => array(
  • ‘name’ => ‘Recipes’,
  • ),
  • ‘public’ => true,
  • ‘has_archive’ => true,
  • ‘supports’ => array(‘title’,’ editor’, ‘custom fields)
  • )
  • );

The new post type will appear in the admin interface, along with posts and pages. It supplies a field for the recipe title and an editor field for the recipe description part. We even added support for custom fields, which will be necessary later.

Setup custom taxonomies for recipe categories and ingredients

In WordPress, taxonomies are not for holding content, like posts; they are for organizing it. It would help if you used the two default taxonomies: categories (hierarchical) and tags (not hierarchical). However, like with post types, you can add your taxonomies. For our recipes database, you could use categories and tags, but they are meant to be used for posts really, so we create our recipe categories and link them to the recipe post type:

  • register_taxonomy(
  • ‘recdb_categories’,
  • array(‘recdb_recipe’),
  • array(
  • ‘label’ => ‘Recipe categories’,
  • ‘sort’ => true,
  • ‘rewrite’ => array(‘slug’ => ‘recipe categories),
  • ‘hierarchical’ => true,
  • ‘show_in_nav_menus’ => true
  • )
  • );

In the admin interface, they will show up under the recipes menu, and there will be a checkbox list on every recipe to sort it into categories. We want it with ingredients, but with a slight difference: they don’t have to be hierarchical because every recipe will have just a plain list of ingredients. Here is how to create an ingredients taxonomy that will work just like ordinary tags. You can manage it from your admin interface and add it to any recipe:

  • register_taxonomy(
  • ‘recdb_categories’,
  • array(‘recdb_recipe’),
  • array(
  • ‘label’ => ‘Recipe categories’,
  • ‘sort’ => true,
  • ‘rewrite’ => array(‘slug’ => ‘recipe categories),
  • ‘hierarchical’ => true,
  • ‘show_in_nav_menus’ => true
  • )
  • );
  • Setup custom fields for ingredient units

We can create new recipes, categorize them, and add ingredients for now. The last missing feature is to add some quantities to the elements because the information that you will need milk while cooking your dinner is useless if you don’t know how much. Here are custom fields coming into the picture. You have to add a custom field for all ingredient tags you are adding to a recipe. The field’s name is always a quantity that allows us to read them as an array later. The value has to be formatted like this: taxonomy-term-slug: string. Here are some concrete examples of the custom fields on our recipes:

  • quantities -> water:100ml
  • quantities -> milk:200ml
  • quantities -> sugar:20g
  • Embedding recipes in your theme

I assume you have a working theme and want to add special templates for recipes. Begin with adding recipe categories to your menus. Are you using custom menus? They will appear in the menu editor like ordinary categories (you might have to activate them in your screen options panel). Now, you should be able to navigate to the added recipe categories on your website. The containing recipes are displayed with your index.php or another matching template.

The next step is to build a custom loop for recipes. We will create quite an ordinary circle, including the title and the content template tags. Building the ingredients list is a bit special, though. For this, we must first get the quantities’ meta-value using get_post_meta. Then, we loop through the quantities, reading both the amount and the ingredient, and finally, we provide an ingredient link, which leads to a site listing recipes with the same element. Create a file called loop-recipes.php in your template directory and add the following loop:

  • <?php if (have_posts()): while (have_posts()): the_post();?>
  • <div class=”recipe”>
  • <h2><?php the_title();?></h2>
  • <ul class=’ingredients’>
  • <?php
  • if (is_single()):
  • $quantities = get_post_meta(get_the_ID(),’quantities’);
  • for each ($quantities as $quantity):
  • $quantity = explode(‘:’,$quantity);?>
  • <li>
  • <?php echo $quantity[1];?> <a href='<?php echo get_term_link($quantity[0],’recdb_ingredients’);?>’>
  • <?php echo $quantity[0];?>
  • </a>
  • </li><?php
  • the end for each;
  • endif;
  • ?>
  • </ul>
  • <?php
  • if (is_single()):
  • the_content();
  • Else:
  • the_excerpt();
  • ?><a href=”<?php the_permalink();?>”>Read recipe</a><?php
  • endif;?>
  • </div>
  • <?php endwhile; endif;?>

Now, it is only left to embed the loop in the template files for recdb_categories and recdb_ingredients and add a template to show a full recipe. Create three files in your template directory: taxonomy-recdb_categories.php, taxonomy-recdb_ingredients.php, and single-recdb_recipe.php. The following codes go into the category template:

  • <?php get_header();?>
  • <h1>Category: <?php single_cat_title();?></h1>
  • <p>List of recipes in category <?php single_cat_title();?></p>
  • <?php get_template_part(‘loop’,’recipes’);?>
  • <?php get_footer();?>
  • Here is the code for the ingredients template:
  • <?php get_header();?>
  • <h1><?php single_cat_title();?></h1>
  • <p>List of recipes, which use <?php single_cat_title();?></p>
  • <?php get_template_part(‘loop’,’recipes’);?>
  • <?php get_footer();?>
  • And finally, the single recipe template:
  • <?php get_header();?>
  • <?php get_template_part(‘loop’,’recipes’);?>
  • <?php get_footer();?>

Conclusion

Following all the steps, you should have a fundamental but working recipe database running. Of course, the way to add ingredients is horrifying from a user’s point of view, but this tutorial isn’t about usability. It is a starting point for one who wants to take WordPress as a base for web apps that aren’t blogs or ordinary websites. The vital energy, I think, is to understand the WordPress customization abilities and learn to map them to your use case.

Surely, there are some drawbacks to using WordPress for your web app, and you shouldn’t ignore them. However, once you have decided to go the WordPress way, you get many cool features to overcome the disadvantages.

Share

Alcohol scholar. Bacon fan. Internetaholic. Beer geek. Thinker. Coffee advocate. Reader. Have a strong interest in consulting about teddy bears in Nigeria. Spent 2001-2004 promoting glue in Pensacola, FL. My current pet project is testing the market for salsa in Las Vegas, NV. In 2008 I was getting to know birdhouses worldwide. Spent 2002-2008 buying and selling easy-bake-ovens in Bethesda, MD. Spent 2002-2009 marketing country music in the financial sector.