> ## Documentation Index
> Fetch the complete documentation index at: https://docs.pads4.com/llms.txt
> Use this file to discover all available pages before exploring further.

# 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.

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## **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#`)*

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## **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**.

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## **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**.

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## **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).

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## **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.                  |

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## **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. |

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## **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.

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## **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.

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## **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.