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Business object

The heart of every Nuclos application: business objects define your data model – table, forms and API are generated automatically.

KONZEPT LOW-CODE UPDATED: JUL 2026 APPLIES TO NUCLOS 4.2026.X

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What is a business object?

In Nuclos all of your company's data is organised in business objects (BO). A business object corresponds to an entity in the data model – an abstraction of real things such as customer, article or order. From the BO, Nuclos automatically derives the database table, the forms and the REST/rule API.

BO and process

A business object may – but need not – have a status model. Use it to model processes, e.g. ordered → delivered → paid.

Menu: Configuration → Business object

1. Create, edit, delete a business object

The first page of the BO wizard lists the existing business objects (filterable and sortable).

Create: enter a name and choose a Nuclet. The name is the basis for the table name; the internal name may have at most 25 characters. Duplicate names are only allowed in different Nuclets.
Edit: select the BO and continue with Next.
Delete: removes metadata and the database table. Only possible once no other BO references it.

Caution

Deleting removes all data irreversibly. A deleted BO cannot be restored.

Step 1: overview and creation of business objects.

2. General properties

Label/window title, table name / internal BO name (basis of the method names in the BusinessRule API).
Editable? – if unchecked, the BO is read-only (e.g. interface data, fixed value lists).
Menu path (separate sub-folders with \), custom icon, keyboard shortcut.
Search form required/opened directly, split view, history.
Enable a status model (then it becomes mandatory) and an identifier prefix (e.g. KU0716-00001).
Mandator dependency incl. initial fill and uniqueness per mandator.
Technical variants: virtual BO (view), write proxy, thin BO (IDs only, more performance), proxy BO/interface, generic BO, object generator for cloning.

Step 2: general properties of the business object.

3.–4. Define and edit attributes

Attributes (fields) can be created manually or taken over from another BO or a database table. Set the order via arrow buttons or drag-and-drop; it is the default of the list view.

Step 4: maintain the business object's attributes.

Data types

Data type	Java type	DB type	Length	Note
Text	java.lang.String	varchar	255	Standard text field
Memo	java.lang.String	varchar	4000	Multi-line text
Text (Large Object)	java.lang.String	clob	2147483647	Very long text
Integer	java.lang.Integer	number	9	Whole number
Decimal (9,4)	java.lang.Double	number	9	Format via pattern, e.g. `#,##0.00`
Yes/No	java.lang.Boolean	number	1	Mandatory, no null values
Date	java.util.Date	date	–	Format via pattern, e.g. `dd.MM.yyyy`
Reference field	java.lang.String	varchar	255	Reference to another business object
Lookup field	java.lang.String	varchar	255	Pick from reference BO, only the text is stored
E-mail / PhoneNumber / Hyperlink	java.lang.String	varchar	255/1000	Special data components
Document / Image / Binary (LOB)	–	blob	–	Files and images
Auto number	java.lang.Integer	number	9	Automatically incremented
Encrypted text	–	varchar	255	Stored encrypted

Key attribute properties

Display name (label), description (tooltip), data type, min/max (numbers/dates), multilingual.
Field name (identifier in rules/layout), DB column name, attribute group (for status-dependent rights).
Mandatory, unique (possibly combined), indexed, default value.
Calculation expression (Groovy, live in the form, see client-side rules) vs. calculation rule (data source/database object on read) and calculate on request only.
Background colour (Groovy or data source), history, hidden, modifiable (overrides group/status rights).

Reference field / relation

A reference points to another business object or to an integration point. Options: cascade delete, search field (LOV) and a display pattern of concatenated attributes, e.g. ${kundennummer} - ${name}. A value list provider can be assigned across attributes.

Reference field/relation to other business objects.

5.–6. Actions, contexts and menu

With actions you design several layouts/processes for one BO (e.g. company vs. private customer). Contexts control which subform BOs the web client search includes. The menu path can be refined per action; with New? the input form opens directly.

Step 6: configure the menu.

7. Labelling and tree view

Title (window title/history/tree) and info (tooltip) are built from attributes + static text, e.g. ${kundenname} (${kundennummer}) - ${nuclosState}. In the tree view you embed referencing BOs as well as dynamic BOs and document attachments as child nodes (grouping, folders, reference fields).

Step 7: configure the tree view.

8.–10. Rights, translation and presentation

Rights & locking: maintain permissions per user group and enable the locking logic.
Translate: BO name, menu path, node/tooltip and actions (DE/EN).
Presentation: automatically generate/update a layout (overwrites any existing one!), grouping by attribute groups, subforms, editing fields, row background colour (Groovy).