## Overview

The Open Gantt Chart widget provides a button that opens a Gantt chart in a new browser tab. Rather than offering complete scheduling functionality inline, it acts as a visual entry point to the full Gantt chart experience, giving users immediate visual context while inviting them to explore the detailed view.

**Use when**: You need to show a timeline teaser on overview or summary pages that links to the detailed Gantt experience. Ideal for default layouts where users want a quick visual sense of the schedule without the overhead of a full Gantt interface.

**Alternatives**:
- **Multi-Gantt** - When displaying multiple schedules in an aggregated view
- **Schedule Tree Table** - When users need a tabular WBS structure with inline editing rather than a visual timeline

## Use Cases

### Schedule Overview Dashboard
On a schedule's default page, users often want to see the timeline at a glance without committing to the full Gantt interface. The Single Gantt Link provides this preview, letting users quickly assess timeline health before deciding to dive deeper.

### Project Summary Pages
When creating executive summaries or project portfolio views that show one schedule per project, this widget offers a lightweight way to include timeline information without the performance cost of rendering a full Gantt for each project.

### Navigation-Oriented Layouts
In layouts designed around progressive disclosure, the Single Gantt Link serves as the visual "hook" that draws users toward the detailed Gantt view. It answers "what does the timeline look like?" and invites the follow-up question "what are the details?"

### Read-Only Timeline Preview
For stakeholders who need to see the timeline but don't need editing capabilities, this widget provides appropriate visual information without exposing planning controls.

## Behavior and Capabilities

### Schedule Source Selection
The widget can obtain its schedule data through three mechanisms:
- **Embedding context**: Uses the current page as the schedule, ideal when the widget lives directly on a schedule page
- **Search-based selection**: Finds the appropriate schedule through search criteria, useful when embedding previews on related pages
- **Reference following**: Traverses a reference attribute to locate the schedule, enabling indirect relationships

### Timeline Rendering
The widget renders the schedule's task hierarchy as a Gantt timeline, displaying activities as bars and milestones as diamonds. The rendering is intentionally simplified compared to the full Gantt view, prioritizing quick comprehension over exhaustive detail.

### Dependency Visualization
Cross-links between tasks (dependency arrows) can be shown or hidden. Hiding them results in a cleaner, less cluttered preview that's easier to scan quickly.

### Navigation Behavior
The "Link" in the widget name reflects its primary interaction model: clicking the preview navigates users to the full Gantt view where they can perform detailed planning and editing.

## Design Considerations

### Preview vs. Full Experience Trade-off
This widget deliberately sacrifices functionality for simplicity. It answers "what does the timeline look like?" but not "how do I edit this task?" This separation of concerns keeps overview pages fast and focused while reserving the full feature set for dedicated planning views.

Consider hiding dependency arrows in preview contexts. While dependencies are crucial for planning, they add visual complexity that can overwhelm a quick preview. The full Gantt view remains available for users who need dependency information.

### Performance Implications
As a lightweight preview widget, Single Gantt Link is designed for fast loading. This makes it suitable for pages where users expect quick access to information, such as default layouts or dashboard contexts. Avoid overloading the same page with multiple heavyweight widgets if this preview is meant to stay snappy.

### Context Requirements
The widget requires schedule context to function. When placing it on non-schedule pages, you must configure how the widget should find its schedule (through search or reference). On schedule pages, the embedding context typically provides the needed information automatically.

### Plugin Dependency
This widget is part of the Project Planning plugin (cf.projektplanung namespace). It's only available in workspaces where this plugin is installed and will not function in generic cplace environments.

## Related Widgets

### Within the Gantt Widget Family

**Schedule Tree Table**: While Single Gantt Link provides a visual timeline preview, the Schedule Tree Table offers a tabular WBS view with inline editing capabilities. These widgets often coexist in different tabs or layouts, serving different interaction needs for the same schedule data.

**Multi-Gantt**: When you need to visualize multiple schedules together (such as a portfolio view across projects), the Multi-Gantt widget handles aggregation. Single Gantt Link is specifically scoped to one schedule, making it simpler but less flexible for cross-project views.

### Complementary Widgets

**Layout Tabs Widget**: Single Gantt Link works well alongside Layout Tabs, providing immediate timeline context on the overview while tabs offer navigation to the full Gantt, board view, or other specialized layouts. Users see the preview first and can expand or switch tabs as needed.

**Attribute Widgets**: Overview layouts typically pair the timeline preview with key attribute displays (status, dates, owner) to give users a complete picture without requiring navigation.

## Layout Context

The Single Gantt Link typically appears on schedule default layouts as a visual centerpiece, positioned after status information and summary attributes but before navigation elements like tabs. This placement supports a progressive disclosure pattern:

1. Quick facts (attributes, status indicators)
2. Visual timeline preview (this widget)
3. Navigation to detailed views (tabs, links)

This arrangement lets users get immediate visual context while making deeper exploration easily accessible.

## Data Model Context

The widget visualizes the task hierarchy within a schedule. Schedules contain activities (which can nest into sub-tasks) and milestones, all rendered as timeline elements. The hierarchical structure appears in the Gantt's vertical organization, while temporal relationships (start dates, durations, deadlines) drive the horizontal positioning.