Business Logic screens

This page documents the Business Logic branch of the Explorer, apart from workflows (see Workflow Designer): Business Rules, Scripts, Expressions and Validations. Three of the other nodes, Approval Flows, Event Handlers, Scheduled Jobs and Notifications, are marked "coming soon" in the Explorer; scheduled work is covered in Jobs and scheduler and events in Events and automation.

Studio has three different kinds of "rule". They are easy to confuse:

Kind	Where it is authored	What it does
Business rule (the rule artifact)	Business Logic > Business Rules	Runs an action chain when an event matches, with a priority band. Documented below.
Form rule	A form's Rules tab in the Form Designer	Shows, hides, requires or locks fields and sections based on other fields. See Form Designer.
Entity rule	A plugin's metadata/rules files, or the API (erp plugin op rule-create)	Runs on the server before or after a record is created, updated or deleted. See Reference: entity rule definition.

Business Rules

Where to find it

Workspace > Business Logic > Business Rules. Page key rules. The list creates, edits, publishes and deletes rules; opening one opens the Rule Designer.

Key concepts

A rule is a named, versioned definition: an event pattern that says when it applies, an optional condition, optional watched fields, a scope that limits where it applies, a priority, and an action chain that runs when it matches. A rule has a draft and published versions like other artifacts, with autosave, crash recovery and a stale-draft guard.

Rule Designer, Properties

Field	Description
Rule name	Required and unique. A duplicate is reported as duplicate-rule.
Event pattern	A dotted pattern such as department.onChange or order.*, or a catalog event. An invalid pattern is reported as invalid-event-pattern.
Catalog event	A picker over the platform's event catalog. Choosing one sets the event pattern.
Watched fields	Comma separated. The rule fires only when one of them actually changed. Empty means always.
Enabled	Switches the rule on or off without unpublishing it.
Suppress self-trigger	Prevents the rule's own actions from re-triggering it. Without it the designer warns possible-self-trigger.
Priority band	See below.
Custom priority and Priority override (deliberate out-of-band)	A priority outside the four bands. A priority that is not a band value and is not marked as a deliberate override is reported as out-of-band-priority.
Metadata version	Required to publish (missing-marketplace-metadata). Used by the marketplace.

Priority bands

Rules run in priority order, lowest number first.

Band	Priority	When it runs
Security	1	Before commit. Can veto the operation.
Validation	5	Before commit. Can veto the operation.
Business rule	10	After validation.
Notification	100	Asynchronously, after commit.

Scope

The scope limits the rule to one block, form, page, workflow or role. Each dimension is a text field; a rule with no scope applies everywhere. A role scope matches when the acting user holds that role.

Condition

A condition builder works on event data. Bare names refer to the event's own data and are never flagged as unknown. Operators are the same as for workflow transitions.

Action chain

The chain is the list of steps the rule runs. Each step has a type, a configuration, and optional condition, retry and on-error settings. The step types and their fields are in How a screen is built. Steps can contain branches that are themselves chains. Plugin-provided action types appear with a raw JSON editor.

Typical step editors:

Step	Fields
Run integration	What to run (a connector, or a flow that runs in the background), Type, Name, and input values (${form.field} sends a form value).
Call API	Request URL (map form values with ${form.field}), Method, parameters.
Set value	Target field (bare names write to the form scope; prefix to target another, for example page.total), Value kind (text or expression, boolean), Value (a literal or a ${...} reference).
Validate	Check expression and Failure message (shown as ${error.message} in on-failure chains; empty uses a default).
Show field	Field and Visible.
Navigate, Open dialog, Close dialog	Route; Dialog id (blank closes the most recent overlay); Page id and Open in.

Problems panel

The panel shows the rule engine's own diagnostics. Errors block publishing; warnings do not.

Code	Meaning
missing-field, invalid-field	A required property is missing or has the wrong shape.
invalid-event-pattern	The event pattern is not valid.
invalid-condition	The condition is malformed.
invalid-watched-fields	Watched fields are not a list of field names.
invalid-actions	A step in the chain is invalid; the path points to the step (for example actions[0].config.url).
duplicate-rule	Another rule has the same name.
out-of-band-priority	Priority is not one of the bands and not marked as an override.
missing-marketplace-metadata	Metadata version is missing.
possible-self-trigger (warning)	The rule's actions may trigger the rule again.

History

The History tab lists versions with a domain-aware diff.

API and CLI

/api/v1/authoring/rules (draft, publish, versions). erp artifact list|get|create|update|publish --type rules.

Scripts

Where to find it

Workspace > Business Logic > Scripts. Page key actions.

What a script is here

The Scripts folder lists shared actions: single action steps stored as their own versioned artifact so rules, forms and pages can reuse them. A shared action is exactly one step of an action chain, with all of its settings.

Action Designer

Area	Description
Step editor	The same editor as the rule action chain: typed configuration for the built-in step types, a raw JSON fallback for plugin step types, the reliability settings (retry, onError strategies continue, stop, retry, compensate, rollback, ignore, custom), and nested branch chains.
Description	Free text.
Enabled	Switches the action on or off.
Metadata version	Required to publish.
Problems	Validation of the step against the real action registry. Publishing is blocked while errors exist.

Every edit is one undoable change. Shared actions are versioned like other artifacts.

API and CLI

/api/v1/authoring/actions. erp artifact ... --type actions. Schema: Reference: action.

Expressions

Where to find it

Workspace > Business Logic > Expressions. Page key expressions. The Expression Library lists named expressions.

What it holds

A named expression is a reusable formula that rules, forms and pages can refer to by name. Expressions are saved compiled. They do not have a draft and publish lifecycle: saving is an upsert by name, the version increases only when the source changes, and Recompile moves an expression to the current engine version.

Fields

Field	Description
Expression name	Saving under an existing name updates that expression.
Expression source	The formula.
Return type	Optional. Documentation, not enforcement.

The list shows Name, Returns, Version (v<n>) and Engine (compiled or not compiled).

Saving

Compile & save first validates the source with the engine's own validator, using the rule vocabulary. Compile diagnostics are shown verbatim and an expression that does not compile is not saved. A successful save shows the version and the engine version it compiled against. Recompile is audited and records the new engine version.

Validations

Where to find it

Workspace > Business Logic > Validations. Page key validations.

What it shows

A read-only, workspace-wide list of every validation, gathered from the forms. Nothing is stored separately: each row is read from a form definition, and selecting a row opens that form in the Form Designer.

Columns

Column	Description
Name	The field and rule, for example email required, or the rule id.
Type	Required, Pattern, Length, Min/Max Value, Unique for field constraints; Cross Field, Form or Field Rule for form-level validation rules.
Entity	The entity of the form.
Form	The form that defines it.
Status	Active or Inactive.

Where validations are authored

Field constraints are set in the field's properties in the Form Designer. Form-level validations (for example a cross-field rule) are authored on the form's Validations tab. Reusable named checks (pattern, range, cross-field expression) are covered in Workflows, rules and validations.

Related

Workflow Designer, Form Designer, Business Logic, How the pieces fit together.