Nodes¶
Nodes are the visual elements on the canvas that represent workflow components. Each node has a type, a label, and optional configuration.
Node types¶
Event nodes (start)¶
Event nodes are the entry points of a workflow. They define what triggers the workflow to execute.
- Visual style: Rounded rectangle with a distinct color.
- Examples: "Entity is created", "Cron runs", "Form is submitted".
- Behavior: A workflow can have multiple event nodes, creating separate flows on the same canvas.
Element nodes (actions)¶
Element nodes represent actions -- tasks that the workflow performs when executed.
- Visual style: Standard rectangle.
- Examples: "Send email", "Set field value", "Create entity".
- Behavior: Actions execute in the order defined by the edges connecting them.
Gateway nodes¶
Gateways are decision points that control how the workflow branches. They evaluate conditions and route execution accordingly.
- Visual style: Diamond shape.
- Behavior: Gateways can split a single flow into multiple paths or merge multiple paths back together.
Subprocess nodes¶
Subprocess nodes reference other workflow models, allowing you to reuse existing workflows as building blocks.
- Visual style: Double-bordered rectangle.
- Behavior: When execution reaches a subprocess node, the referenced workflow is invoked.
Placeholder nodes¶
Placeholder nodes are temporary nodes created during condition-first authoring. When you select a condition from a node's quick-add popup (instead of an action), the modeler creates a placeholder node connected by the condition edge.
- Visual style: Dashed amber border with a striped background and a pulsing "Select action..." button.
- Behavior: Placeholder nodes must be replaced with a real action or gateway before the model can be saved, tested, or closed. Click the "Select action..." button to choose the component that should replace it.
Warning
A model containing placeholder nodes cannot be saved. The Save, Test, and Close buttons will display an error message until all placeholders are resolved.
Common operations¶
Selecting a node¶
Click on a node to select it. The Property Panel opens with the node's configuration.
Moving a node¶
Click and drag a node to reposition it. Nodes snap to a 20px grid.
Configuring a node¶
With a node selected, use the Property Panel to:
- Edit the label (click the label text).
- Fill in the configuration form fields.
- Add an annotation note for documentation.
Deleting a node¶
Select a node and press Delete, or use the delete option in the Property
Panel. Deleting a node also removes all edges connected to it.
Quick-add successor¶
Hover over any node to reveal a + button. Click it to open a popup with components that can follow this node. The popup shows actions, gateways, and conditions:
- Actions and gateways: Selecting one creates a new node and connects it to the source node.
- Conditions (condition-first authoring): Selecting a condition creates a placeholder node as the successor, with the condition pre-attached to the connecting edge. The condition edge is automatically selected so you can configure it immediately. See Placeholder nodes above.
Type filter¶
The popup includes a collapsible Filter panel that lets you narrow the component list by type:
- All (default): Shows actions, conditions, and gateways.
- Actions: Shows only action components.
- Conditions: Shows only condition components.
- Gateways: Shows only gateway components.
Click the "Filter" toggle to expand or collapse the panel. An active filter is indicated by a badge on the toggle button.
Additional filtering¶
The quick-add popup also respects:
- Context filtering: Only shows components valid for the selected context.
- Dependency rules: Hides components that require predecessor types not present in the workflow.
- Search threshold: When fewer than 15 components are available, the search field is hidden for simplicity.