fragments

Mendix Fragments Skill

When to Use This Skill

Use this skill when:

• Defining reusable widget groups with define fragment
• Inserting fragments into pages or snippets with use fragment
• Listing or inspecting fragments with show fragments / describe fragment
• Building multiple pages that share common widget patterns (footers, form fields, buttons)
• Avoiding copy-paste of repeated widget structures across pages

What Are Fragments?

Fragments are script-scoped, transient widget groups:

• Defined once, reused in multiple pages/snippets within the same script
• Not persisted in the MPR file — they exist only during script execution
• Widgets are deep-cloned on expansion (each USE gets independent copies)
• Optional prefix support to avoid name conflicts when using the same fragment multiple times

Syntax Reference

DEFINE FRAGMENT

define fragment SaveCancelFooter as {
  footer footer1 {
    actionbutton btnSave (caption: 'Save', action: save_changes, buttonstyle: primary)
    actionbutton btnCancel (caption: 'Cancel', action: cancel_changes)
  }
};

Multiple top-level widgets:

define fragment CustomerFields as {
  textbox txtName (label: 'Name', attribute: Name)
  textbox txtEmail (label: 'Email', attribute: Email)
  textbox txtPhone (label: 'Phone', attribute: Phone)
};

USE FRAGMENT

Inside a page or snippet body:

create page Module.CustomerEdit
(
  params: { $Customer: Module.Customer },
  title: 'Edit Customer',
  layout: Atlas_Core.PopupLayout
)
{
  dataview dvCustomer (datasource: $Customer) {
    use fragment CustomerFields
    use fragment SaveCancelFooter
  }
};

With prefix (avoids name conflicts):

use fragment SaveCancelFooter as order_
-- Creates: order_footer1, order_btnSave, order_btnCancel

Content Slots — wrap arbitrary content

A plain fragment substitutes a fixed widget group. A content slot lets a fragment wrap arbitrary caller-supplied content — a reusable shell (a card, panel, or section) whose body varies per use. Declare a slot where the caller's widgets should land, then fill it with the use fragment X { … } payload form: