Working with presentations
Viewer Variables
Viewer Variables are powerful tools that allow dynamic, context-driven content in PADS4 presentations. They are customizable variables assigned to each Viewer and automatically filled in during the display of presentations. These variables enable content personalization without the need to create multiple presentations for different locations or devices.
What Are Viewer Variables?
- Viewer-specific placeholders that can dynamically adjust content shown in presentations.
- Used in text, data providers, filters, rules, property bindings, and more.
- Identified in content using the format:
#<Viewer Variable name>#
(Example:#Store Name#)
Where to Define Viewer Variables?
1. System Management Application (Recommended)
- Add and manage Viewer Variables.
- Assign default values that apply to all Viewers.
- Ensures centralized control and prevents unauthorized creation or deletion via PADS4 Agent.
2. PADS4 Agent
- Adjust values for individual Viewers under the Server tab.
- Overwrites the default value assigned in System Management.
3. Viewer Options Window (on the Viewer device)
- Adjust Viewer Variables directly on the Viewer for local adjustments.
Example: Personalized Text with Viewer Variables
If you define a Viewer Variable #Store Name# with the default value “New York Health”, and use this text in a Text Element:
Welcome to the #Store Name#.
During playback, it will automatically display:
Welcome to the New York Health.
If you update the variable in PADS4 Agent or Viewer options (e.g., to “Chicago Health”), the content will adjust without changing the presentation.
Where Can Viewer Variables Be Used?
- Text fields in elements.
- Data Providers (queries, filters, expressions, sort, file paths).
- Rules for dynamic content behavior.
- Property bindings.
- Playlists for media sequences.
- File references (e.g., dynamically select images based on Viewer location).
Automation Examples Using Viewer Variables
| Use Case | Example |
|---|---|
| Personalized store information | Show specific store name and address per Viewer. |
| Product selection based on store size | Filter products based on Viewer Variable like #StoreSize#. |
| Region-specific data | Use #Country# or GPS-based Viewer Variables for localized content. |
| Dynamic map display | Show different maps depending on location variable. |
When Are Viewer Variables Transformed into Actual Values?
| Context | When Replaced |
|---|---|
| Inside data sources (SQL, XML, JSON, RSS) | When Viewer reads or receives data from the source. |
| In Data Providers (filter, sort, expressions) | At start of data retrieval. New variable values affect next retrieval. |
| Inside presentations (text, image, video) | At presentation start. |
| In rules (element, page, presentation rules) | At time the rule is checked (not auto-updated if variable changes). |
| Property bindings (with data provider) | On scheduled data read. |
| Playlists | Replaced when loaded. For alternated playlists, updated at next cycle. |
Playlist Handling with Viewer Variables
- Single-item, non-alternating playlist:
Viewer Variable is replaced at load time and remains static until next load. - Alternating playlist:
Viewer Variable is updated on each interval, allowing dynamic changes.
Important Notes
- Do NOT use Viewer Variables for constantly changing values.
Viewer Variables are not designed to function as high-frequency data sources (use Data Providers for that). - Changes in Viewer Variables do not automatically trigger re-evaluation of all rules or content refresh unless reloaded.
- Files outside Content Library referenced with Viewer Variables may not synchronize properly—keep files inside the Content Library.
Key Benefits
- Centralized content management with dynamic local personalization.
- Single presentation serving multiple Viewers with unique content.
- Easy to update and maintain—change the variable value, not the presentation.
- Enhances automation and targeted communication without complex redesign.