What It Does

JCB allows each field to define PHP "hooks" that are triggered:

• onSave: when the field’s data is being saved
• onGet: when the field’s data is being retrieved for display or processing

These hooks are per-field, defined visually in the GUI, and are injected directly into the generated model or controller logic during compile. This provides pinpoint customization without breaking Joomla MVC conventions.

Types of Hooks

📝 onSave

Run logic right before the field is stored in the database:

• Sanitize or format input
• Combine multiple inputs into a single field
• Generate a slug or token
• Apply conditional business logic (e.g., if X, then modify Y)

📤 onGet

Run logic when data is fetched from the database before it's displayed or processed:

• Reformat values (e.g., date or currency display)
• Replace tokens or placeholders
• Inject dynamic data or perform lazy joins
• Translate stored codes into readable text

How to Configure in JCB

• Go to Field → Rules/Logic → “Custom Save Code” or “Custom Get Code”
• Use valid PHP inside the textarea (no PHP tags needed)
• Reference the current field value as $value
• Return the transformed value at the end

Example

For a field named alias:

On Save (slugify input):

$value = strtolower(preg_replace('/[^a-z0-9]+/', '-', $value));
return trim($value, '-');

On Get (wrap in badge for display):

return '<span class="uk-label">' . $value . '</span>';

Benefits

• ⚙️ Encapsulated logic per field: Keep save/get behavior tightly scoped to the data it affects.
• 🧱 Reduces controller/model overrides: No need for post-processing elsewhere — it happens inline.
• 🧪 Round-trip compatible: Hooks are stored in the database and regenerate during every compile.
• 🔁 Repeatable across components: Field types can carry these hooks by default to simplify reuse.

Conclusion

Save/Get hooks give you field-level logic injection with zero boilerplate. Whether you're transforming data, creating calculated values, or modifying output dynamically, these hooks make your fields smarter — right from the GUI.