Options API for site-wide settings in Wordpress

Introduction

The Options API lets you save and get settings that apply to your whole WordPress site. It helps keep your site settings organized and easy to change.

You want to save a custom setting like a phone number or address for your site.

You need to store a theme or plugin setting that affects the whole site.

You want to let site admins change options from the WordPress dashboard.

You want to keep settings that don't belong to a specific post or user.

You want to retrieve site-wide settings quickly in your theme or plugin code.

Syntax

Wordpress

add_option( string $option_name, mixed $value, string $deprecated = '', string $autoload = 'yes' )

get_option( string $option_name, mixed $default = false )

update_option( string $option_name, mixed $value, string $autoload = null )

delete_option( string $option_name )

add_option saves a new option only if it does not exist yet.

get_option fetches the value of an option, or returns a default if not found.

Examples

Adds a new option named 'site_phone' with the phone number as its value.

Wordpress

add_option('site_phone', '123-456-7890');

Gets the 'site_phone' option value or returns 'No phone set' if it does not exist.

Wordpress

$phone = get_option('site_phone', 'No phone set');

Changes the 'site_phone' option to a new phone number.

Wordpress

update_option('site_phone', '987-654-3210');

Removes the 'site_phone' option from the database.

Wordpress

delete_option('site_phone');

Sample Program

This code shows how to add, get, update, and optionally delete a site-wide setting called 'support_email'. It prints the email before and after updating it.

Wordpress

<?php
// Add a site-wide setting for support email
add_option('support_email', '[e-mail]');

// Get and print the support email
$email = get_option('support_email', 'not set');
echo "Support Email: $email\n";

// Update the support email
update_option('support_email', '[e-mail]');

// Get and print the updated email
$email = get_option('support_email');
echo "Updated Support Email: $email\n";

// Delete the option
// delete_option('support_email');
?>

Important Notes

Options are stored in the WordPress database and loaded on every page load if autoload is 'yes'.

Use unique option names to avoid conflicts with other plugins or themes.

Deleting an option removes it completely from the database.

Summary

The Options API stores site-wide settings in WordPress.

Use add_option, get_option, update_option, and delete_option to manage these settings.

This helps keep your site settings organized and easy to change.

Practice

1. What is the main purpose of the WordPress Options API?

easy

A. To handle user login and authentication

B. To create new posts automatically

C. To store and manage site-wide settings easily

D. To style the website with CSS

Solution

1. Step 1: Understand the role of Options API

   The Options API is designed to store settings that affect the whole site, like site title or custom settings.

2. Step 2: Compare with other options

   Creating posts, user login, and styling are handled by other parts of WordPress, not the Options API.

3. Final Answer:

   To store and manage site-wide settings easily -> Option C

4. Quick Check:

   Options API = site-wide settings [OK]

Hint: Options API is for site settings, not content or style [OK]

Common Mistakes:

• Confusing Options API with post creation
• Thinking it manages user authentication
• Assuming it handles CSS styling

2. Which function is used to retrieve a stored option value in WordPress?

easy

A. add_option()

B. get_option()

C. update_option()

D. delete_option()

Solution

1. Step 1: Identify function purposes

   add_option() adds a new option, update_option() changes it, delete_option() removes it, and get_option() retrieves the value.

2. Step 2: Match retrieval action

   Since we want to get or read the stored value, get_option() is the correct function.

3. Final Answer:

   get_option() -> Option B

4. Quick Check:

   Retrieve option = get_option() [OK]

Hint: Get means retrieve, so get_option() fetches values [OK]

Common Mistakes:

• Using add_option() to get values
• Confusing update_option() with retrieval
• Trying to delete instead of get

3. What will be the output of this code snippet?

add_option('site_color', 'blue');
update_option('site_color', 'green');
echo get_option('site_color');

medium

A. blue

B. null

C. site_color

D. green

Solution

1. Step 1: Understand add_option and update_option

   add_option sets 'site_color' to 'blue'. Then update_option changes it to 'green'.

2. Step 2: Retrieve current value

   get_option('site_color') returns the latest value, which is 'green'.

3. Final Answer:

   green -> Option D

4. Quick Check:

   Updated option value = green [OK]

Hint: Update_option overwrites add_option value [OK]

Common Mistakes:

• Assuming add_option value stays after update
• Expecting null if updated
• Confusing option name with value

4. Identify the error in this code snippet:

update_option('header_text', 'Welcome!');
add_option('header_text', 'Hello!');
echo get_option('header_text');

medium

A. No error, code works fine

B. get_option cannot retrieve 'header_text'

C. update_option cannot update existing options

D. add_option should be called before update_option

Solution

1. Step 1: Understand function order

   add_option adds a new option only if it doesn't exist. update_option updates existing or adds if missing.

2. Step 2: Analyze code order

   Calling update_option first works fine because it adds or updates the option. add_option after will fail to add since the option exists, but this does not cause an error.

3. Step 3: Correct usage

   While add_option before update_option is typical, the code runs without error.

4. Final Answer:

   No error, code works fine -> Option A

5. Quick Check:

   update_option can add option; add_option after does nothing [OK]

Hint: update_option can add option; add_option after does nothing [OK]

Common Mistakes:

• Calling add_option after update_option
• Thinking update_option can't add new options
• Assuming get_option fails here

5. You want to store a site-wide setting that controls whether comments are enabled. Which approach correctly uses the Options API to toggle this setting on and then retrieve it?

hard

A. update_option('comments_enabled', true); echo get_option('comments_enabled');

B. add_option('comments_enabled', true); update_option('comments_enabled', false); echo get_option('comments_enabled');

C. add_option('comments_enabled', true); echo get_option('comments_enabled'); update_option('comments_enabled', false);

D. delete_option('comments_enabled'); add_option('comments_enabled', true); echo get_option('comments_enabled');

Solution

1. Step 1: Understand update_option behavior

   update_option adds the option if it doesn't exist, so calling it first with true sets the value.

2. Step 2: Retrieve current value

   Calling get_option right after returns true, showing comments enabled.

3. Step 3: Toggle setting

   To toggle off, you would call update_option('comments_enabled', false) later. update_option('comments_enabled', true); echo get_option('comments_enabled'); shows correct initial set and get.

4. Final Answer:

   update_option('comments_enabled', true); echo get_option('comments_enabled'); -> Option A

5. Quick Check:

   update_option adds or updates, then get_option reads [OK]

Hint: update_option can add new option; no need to add_option first [OK]

Common Mistakes:

• Calling add_option then update_option without retrieval
• Deleting option unnecessarily
• Expecting add_option to update existing option