Combined Values

The “Combined values” attribute combines values from multiple existing attributes into a new, stored text value. Typical use cases:

• Combining first and last name into “Last name, First name” for display or search

• Creating composite identifiers from multiple fields, e.g. for the attribute Single select or Multi-select

• Preparing output texts that should be stored as fixed combinations

The combination is done via a sprintf format string. All existing MetaModels attributes as well as system meta fields (ID, PID, sorting, etc.) can be selected as source fields.

See also

For multilingual MetaModels, the attribute Translated Combined Values is available.

Installation

The attribute is installed via the Contao Manager or Composer:

composer require metamodels/attribute_combinedvalues

Settings when Creating the Attribute

In addition to the general attribute settings (name, column name, description, unique values, override variants), the attribute offers the following specific options:

Option	Description
Format	sprintf format string that defines how the source values are combined. A placeholder %s must be present for each selected field value. Examples: %s, %s → “Smith, John” %s (%s) → “Product A (Category B)” %s-%s-%s → “2024-01-15” All placeholder variants of sprintf are possible (see https://www.php.net/sprintf).
Fields	Selection of the source attributes in the order in which they are inserted into the format. In addition to MetaModels attributes, system meta fields are also available: ID, PID, sorting, timestamp, variant group, variant base.
Force update	If this checkbox is active, the combined value is automatically regenerated every time one of the source attributes changes. The field is then displayed as read-only in the backend. Without this option, a once-generated value remains unchanged.

Settings in Render Settings

The “Combined values” attribute has no specific render settings. In the attribute list of a render setting, the usual options are available:

Option	Description
Template	Selection of a custom template for the output of the combined value. If no template is specified, the output is as plain text.
CSS class	Optional CSS class added to the output element.

Settings in the Input Form

When the attribute is added to an input form, the following options are available:

Display

Option	Description
Backend class	CSS classes for the display of the field in the backend form (e.g. long for full width).
Template for backend	Selection of a custom widget template for the backend form.
Template for frontend	Selection of a custom widget template for frontend editing (only available if the “Frontend Editing” extension is installed).

Functions

Option	Description
Required field	Makes the field a required field. If “Unique values” is enabled, this is set automatically.
Always save	The field is saved even if its value has not changed. Set automatically when “Force update” is active.

Overview (backend filter and search)

Option	Description
Filterable	The attribute is available in the backend as a filter criterion.
Searchable	The attribute is available in the backend as a search field.

Filter Rules

The “Combined values” attribute can be used with the following filter rules:

Filter rule	Note
Text search	Free text input for searching in the combined value.
Simple lookup	Filters by an exact or partial value via a URL parameter.
Single select	Selection of a value from a list of existing combined entries.
Multi-select	Multiple selection from a list of existing combined entries.
Register	Filters by initial letters of the combined value.
Levenshtein-based search	Similarity search with typo tolerance; requires the package attribute_levenshtein.
Loupe	Full-text index search; requires the package filter_loupe (from MM 2.4).

Special Functions

Uniqueness with automatic numbering

If “Unique values” is active, MetaModels checks after generation whether the combined value already exists. If a duplicate is found, a counter in parentheses is automatically appended: Smith, John (2), Smith, John (3), etc.

Behavior when copying a record

If “Force update” is active, no value is carried over when duplicating a record. The combined value is automatically regenerated when the new record is saved (doNotCopy behavior).

Format placeholders

All sprintf placeholders can be used, not just %s. For example, %05d formats a number with leading zeros to 5 digits. The number of placeholders must match the number of selected fields.

Database storage

The combined value is stored as text NULL. An empty value is stored as NULL (compatible with MySQL Strict Mode).