Post Types

About Post Types

The post type API lets you extend the types of content available in WordPress.

Each type of content, or “post type”, should have a single responsibility. For example, “Post” and “Page” are post types built into WordPress and have separate responsibilities. “Post” is singly responsible for blog posts and “Page” for standard web pages.

“Post” is responsible for only one thing; blog posts. If you want to add a “Book”, type of content, to WordPress you don’t want to cheat and add a category of “Books” to a blog post. This will break single responsibility. Books are not blog posts. You want to create a post type called “Book” for your books.

Getting Started

To get started with post types using TypeRocket read these docs.

  1. Post Types: Making
  2. Post Types: Theming
  3. Post Types: Secured

Adding a Post Type

For terminologies sake, you “register” a “post type” when you want to add a new type of content. With TypeRocket 3.0 you add post types without having to understand the inner-workings of WordPress.

To register a “Book” post type in WordPress you only need one line of code.


This one line of code adds the post type to the admin, sets all the correct labels in the navigation and applicable places, and implements the required WordPress hooks. This would normally take many many lines of code.

Note: you do not need to use any WordPress hook with TypeRocket here.

TypeRocket takes Post Types to the next level. When you create a post type with TypeRocket you are instancing a special PHP object that can do much more.

Let us assign the “Book” post type to a variable to see these features.

$book = tr_post_type('Book');

Custom plural form

In some cases, you will not want TypeRocket to manage the grammar for the post types plural form.

You can set your own by supplying it as the second argument when creating the post type.

tr_post_type('Book', 'Books');

For example when you have other ideas altogether.

tr_post_type('Person', 'Team');

Setting an Icon

To set a custom menu icon use the setIcon() method.


Note: Browse the “dev” TypeRocket plugin page in the admin under the "Icons" tab to see the list of options.

Title Placeholder Text

By default "Enter title here" is the placeholder text of every post type. You can change this with TypeRocket, without hooks, by using the setTitlePlaceholder() method.

$book->setTitlePlaceholder( 'Enter book title here' );

Forms and Fields

There are 4 place to add custom content within the <form> element for each post type. You can open up these sections with 4 different methods: setTitleForm() for after the title, setTopForm() for before the title, setBottomForm() for the very bottom and setEditorForm() for after the editor.

Take a look at opening up a content section after the title area.


When TR_DEBUG is set to true, as it is by default, TypeRocket shows you where the section was opened and suggests a function to be used to add content.

Note: this applies to all 4 methods.

setTitleForm Debug

Suggested function

By creating the suggested function you are able to start printing content to the screen.

function add_form_content_book_title() {
    echo "<h2>My Book Content</h2>";


Alternatively, when setting a form section you can supply an anonymous function as a callback to do the same.

Take a look at adding content after the editor using a callback.

$book->setEditorForm(function() {
    echo "<h2>My Book Content</h2>";


Adding fields to a post type can be done with the form content methods.

$book->setEditorForm(function() {
    $form = tr_form();
    echo $form->text('Custom Field Name');

Set Archive Slug

To set the slug for the custom post type and change the default use the method setSlug().


Any time you add a new post type or change the slug you need to flush the WordPress rewrite rules.

Note: Flush rewrites by clicking "Settings > Permalinks > Save Changes".

Setting Admin Only

Sometimes you don't want post types to have an archive or single pages. You can use the setAdminOnly() method to keep a post type out of the front-end.

Take a look at making a new post type that is admin only.

tr_post_type('Store Manager')->setAdminOnly();

Set Archive Page Limit (Core v3.0.13)

You can set the number of posts that appear on the post types archive page using the setArchivePostsPerPage() method.

The setArchivePostsPerPage() takes one aurgument:

  • limit - An integer -1 for all posts and any positive number for the specific limt.
$member = tr_post_type('Member');

Apply: Taxonomy and Meta Boxes

Adding Registrable (PostType, Taxonomy, MetaBox) object instances like a Taxonomy or MetaBox is extremely simple when using the TypeRocket post type object.

To add a Taxonomy to a post type instance a Taxonomy and then use the apply() method.

$publisher = tr_taxonomy('Publisher');

To add a MetaBox it is just as simple.

$bookDetails = tr_meta_box('Book Details');

Get Applied Registrable Objects

To see what objects have been applied use the getApplied() method.

$uses = $book->getApplied();

Advanced usage of apply

You can also apply as many Registrable objects as you like using each as a new parameter.

$publisher = tr_taxonomy('Publisher');
$bookDetails = tr_meta_box('Book Details');
$book->apply($bookDetails, $publisher);

Also, an array. You can decide.

$publisher = tr_taxonomy('Publisher');
$bookDetails = tr_meta_box('Book Details');
$book->apply( [$bookDetails, $publisher] );

Setting and Getting the ID

The ID is used to specify the name that WordPress associates with your post types. It is also registered under the ID. When you register "Book" with TypeRocket the id is set to "book".

You can change the ID using the setId() method.


Get the ID

$bookId = $book->getId();


There are 5 methods for dealing with arguments. Arguments are used when the post type is being registered. All arguments can be found in the WordPress codex.

These methods are: getArguments(), setArguments(), getArgument(), setArgument() and removeArgument().

  1. getArguments() returns the full array of arguments.
  2. setArguments() takes an array of arguments.
  3. getArgument() return an argument by its key.
  4. setArgument() sets an argument by a key.
  5. removeArgument() removes an argument by its key.

Take a look at using all the methods without affecting the already set values.

$args = $book->getArguments();
$args = array_merge( $args, [ 'public' => true ] );
$book->setArguments( $args );
$public = $book->getArgument( 'public' );
$book->removeArgument( 'public' );
$book->setArgument( 'public', $public );

Add Table Columns (Core v3.0.13)

You can add and remove columns from the admin post type index page table using TypeRocket. Here we will use a post type of person for our examples. Also, we will have one custom field so we can add it in a custom table column.

$person = tr_post_type('Person', 'People');
$person->setTitleForm(function() {
    $form = tr_form();
    echo $form->text('Job Title');
    echo $form->image('Photo');

Add Column

To add a column it needs to match the custom field's name.

$person->addColumn('Job Title');

If the custom field is grouped then you need to use the base group name.

The addColum() method takes up to 5 aurguments.

  1. field - The name of the field to add. You can use any string format but lowercase letters and _ (underscores) should be used for precision.
  2. sort - The column is sortable true or false.
  3. label - The tabled header column label.
  4. callback - The value to be displayed in the column.
  5. order_by - How the field should be ordered 'string' or 'number'.

Here is an advanced example:

$person->addColumn('photo', true, 'Photo', function($value) {
    echo wp_get_attachment_image($value, 'thumbnail');
}, 'number');

Remove Column

You can remove a column using the removeColumn() method. The removeColumn() method takes 1 string argument and it needs to match field's name.


REST API (Core v3.0.13)

You can also set the WordPres post types REST API resource location using the setRest() method.


Registration Hook: Action

WordPress gives you a hook when a post type is registered. This makes registering post types developer friendly. This hook exists to let plugin developers limit post type conflicts.

You can modify the registration if you need to from here.

add_action('registered_post_type', function($postType, $args) {}, 10, 2);