Advanced Custom Fields plugin in Wordpress - Step-by-Step Execution

Concept Flow - Advanced Custom Fields plugin

Install ACF Plugin

↓

Create Field Group

↓

Add Custom Fields

↓

Assign Field Group to Post Types

↓

Edit Post/Page

↓

Fill Custom Fields

↓

Use get_field() in Theme

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Display Custom Data on Site

This flow shows how you install the plugin, create fields, assign them, fill data, and display it on your site.

Execution Sample

Wordpress

<?php
// Get and display a custom field value
$value = get_field('subtitle');
if ($value) {
  echo '<h2>' . esc_html($value) . '</h2>';
}
?>

This code fetches the 'subtitle' custom field and shows it inside an H2 tag if it exists.

Execution Table

Step	Action	Function Call	Field Key	Value Retrieved	Output
1	Load post edit screen	N/A	N/A	N/A	Custom fields appear for editing
2	User enters 'My Subtitle' in 'subtitle' field	N/A	subtitle	My Subtitle	Value saved in database
3	Theme calls get_field('subtitle')	get_field('subtitle')	subtitle	My Subtitle	Returns 'My Subtitle'
4	Check if value exists	if ($value)	subtitle	My Subtitle	Condition true, proceed
5	Echo value inside <h2>	echo '<h2>' . esc_html($value) . '</h2>';	subtitle	My Subtitle	<h2>My Subtitle</h2> rendered on page
6	End of script	N/A	N/A	N/A	Output displayed on site

💡 Script ends after displaying the custom field value if it exists.

Variable Tracker

Variable	Start	After Step 3	After Step 4	Final
$value	null	'My Subtitle'	'My Subtitle'	'My Subtitle'

Key Moments - 3 Insights

Why does get_field('subtitle') sometimes return null?

If the custom field 'subtitle' is empty or not assigned to the post, get_field returns null. See execution_table step 3 where the value is retrieved.

Why do we check if ($value) before echoing?

To avoid showing empty HTML tags or errors if the field is empty. This is shown in execution_table step 4 where the condition decides if output happens.

How does ACF know which fields to show on the post edit screen?

Because you assign field groups to post types or templates in the plugin settings, as shown in concept_flow step 'Assign Field Group to Post Types'.

Visual Quiz - 3 Questions

Look at the execution_table, what is the value of $value after step 3?

A null

B empty string

C 'My Subtitle'

D false

💡 Hint

Check the 'Value Retrieved' column at step 3 in the execution_table.

At which step does the script decide whether to display the subtitle or not?

A Step 4

B Step 2

C Step 5

D Step 6

💡 Hint

Look at the 'Action' column where the condition if ($value) is checked.

If the user leaves the 'subtitle' field empty, what will get_field('subtitle') return?

A 'My Subtitle'

B null

C 0

D An error

💡 Hint

Refer to key_moments where get_field returns null if no value is set.

Concept Snapshot

Advanced Custom Fields (ACF) plugin lets you add custom fields to posts.
Create field groups and assign them to post types.
Fill fields in post editor.
Use get_field('field_name') in theme to get values.
Check if value exists before displaying.
Escaping output is important for security.

Full Transcript

The Advanced Custom Fields plugin allows WordPress users to add extra fields to posts or pages easily. First, you install the plugin, then create a group of custom fields. You assign this group to certain post types so that when editing those posts, the fields appear. Users fill in these fields with data. In the theme code, you use the function get_field with the field name to retrieve the saved value. Before showing it on the site, you check if the value exists to avoid empty output. Finally, you display the value safely inside HTML tags. This process helps customize content without coding complex database queries.