Component Designer

Design individual components (services, forms, entities, plugins) and document them.

Activation

Activate when you detect:

• "Design X component" or "Design the service"
• "Create spec for the form"
• Breaking down architecture into pieces
• Need detailed design for a single component

Workflow

1. Identify Component Type

Ask if unclear:

What type of component is this?
1. Service (business logic)
2. Form (user input)
3. Entity (data storage)
4. Plugin (extensible behavior)
5. Controller (routing)

2. Gather Component Details

Ask based on type:

For Services:

1. What operations does this service perform?
2. What other services does it need?
3. Should it dispatch events?

For Forms:

1. What type? (ConfigFormBase, FormBase, ConfirmFormBase)
2. What fields are needed?
3. What validation?
4. What happens on submit?

For Entities:

1. Content entity or config entity?
2. What fields/properties?
3. What relationships to other entities?
4. Access control needs?

For Plugins:

1. What plugin type?
2. What does each plugin variation do?
3. What configuration does it need?

3. Find Pattern Reference

Use core-pattern-finder skill to locate a reference implementation in core.

4. Create Component Document

Use Write tool to create {project_path}/architecture/{component_name}.md:

# Component: {ComponentName}

## Type
{Service | Form | Entity | Plugin | Controller}

## Purpose
{One paragraph from user input}

## Interface

### Public Methods
| Method | Parameters | Returns | Description |
|--------|------------|---------|-------------|
| methodName() | $param: Type | ReturnType | What it does |

### Events (if service)
| Event | When Dispatched |
|-------|-----------------|
| event.name | Condition |

## Dependencies

| Service | Purpose |
|---------|---------|
| entity_type.manager | {why needed} |

## Pattern Reference
Based on: `{path from core-pattern-finder}`

Apply from reference:
- {what to copy}

Adapt for our needs:
- {what to change}

## File Locations
- Class: `src/{Type}/{ComponentName}.php`
- Service definition: `my_module.services.yml`
- Routing: `my_module.routing.yml` (if controller)

## Acceptance Criteria
- [ ] {criterion 1}
- [ ] {criterion 2}
- [ ] {criterion 3}

5. Update Main Architecture

Use Edit tool to add component reference to architecture/main.md:

## Components

### {ComponentName}
Type: {type}
Purpose: {one line}
Design: See `architecture/{component_name}.md`

6. Confirm

Show user:

Component designed: {ComponentName}

Files created:
- architecture/{component_name}.md

Based on core pattern:
- {pattern_reference}

Ready for implementation in Phase 3.
Review the design? (yes/no)

Stop Points

STOP and wait for user:

• After asking component type
• After asking for details
• Before creating files
• After showing confirmation