# Session Manipulation API – Java API Reference

The **Session Manipulation Java API** provides runtime‑level access to **session‑scoped business objects** during CRUD and process execution.

This API allows developers to **read, modify, and inject data into the session context** before data is persisted to the database or after data is retrieved, without directly modifying the database schema.

***

### ObjectManipulation Interface

The `ObjectManipulation` interface is the core entry point for interacting with session data at runtime.

```
public static final ObjectManipulation DEFAULT = new ObjectManipulationImpl();

public <T> T get(String expr);

public <T> void set(String expr, T newvalue);

public <T> void set(String expr, T newvalue, String processName);
```

#### Method Overview

| Method                                          | Description                                |
| ----------------------------------------------- | ------------------------------------------ |
| `get(String expr)`                              | Retrieves session data using an expression |
| `set(String expr, T value)`                     | Updates session data                       |
| `set(String expr, T value, String processName)` | Updates session data with process context  |

***

### Reading Session Data (get)

The `get()` method retrieves session‑scoped data using a **runtime expression**.

#### One‑to‑One Object Access

```
ObjectManipulation.DEFAULT.get("MD1161858889");
```

Output:

```
{SOFTWARE_ASSET_ID=216, IP_ADDRESS=null, URL=null}
```

Access a specific attribute:

```
ObjectManipulation.DEFAULT.get("MD1161858889.SOFTWARE_ASSET_ID");
```

Output:

```
216
```

***

### Writing Session Data (set)

The `set()` method updates session‑scoped data at runtime.

```
ObjectManipulation.DEFAULT.set(
    "MD1161858889.SOFTWARE_ASSET_ID",
    7777
);
```

This updates the value in the session context but **does not directly persist to the database** unless a subsequent save operation occurs.

***

### Handling One‑to‑Many Data Structures

For one‑to‑many relationships, session data is represented as a **list of maps**.

#### Retrieve All Records

```
ObjectManipulation.DEFAULT.get("MD1161833204");
```

Output:

```
[
  {SOFTWARE_ASSET_ID=216, ATTACHMENT_ID=208, FILE_PATH=null, KEY={...}},
  {SOFTWARE_ASSET_ID=216, ATTACHMENT_ID=209, FILE_PATH=null, KEY={...}},
  {SOFTWARE_ASSET_ID=216, ATTACHMENT_ID=210, FILE_PATH=null, KEY={...}}
]
```

***

#### Retrieve a Specific Index

```
ObjectManipulation.DEFAULT.get("MD1161833204[0]");
```

***

#### Retrieve Attribute Values Across All Records

```
ObjectManipulation.DEFAULT.get("MD1161833204.SOFTWARE_ASSET_ID");
```

Output:

```
[216, 216, 216]
```

***

#### Retrieve Attribute by Index

```
ObjectManipulation.DEFAULT.get("MD1161833204.SOFTWARE_ASSET_ID[0]");
```

Output:

```
216
```

***

### Updating One‑to‑Many Records

To update a specific record in a collection, pass a map representing the new values.

```
HashMap map = new HashMap() {{
  put("SOFTWARE_ASSET_ID", "9999");
  put("IP_ADDRESS", "/x/y/x.pdf");
  put("URL", null);
}};

ObjectManipulation.DEFAULT.set("MD1161833204[0]", map);
```

This replaces the session data for the selected record.

***

### Inserting a New Record into a Collection

To create a new record in a one‑to‑many relationship, specify the operation type:

```
ObjectManipulation.DEFAULT.set(
    "MD1161833204",
    map,
    "INSERT"
);
```

This creates a **new session record**, which can later be persisted during a save operation.

***

### Process‑Aware Session Updates

The overloaded `set()` method allows session updates to be scoped to a specific process.

```
ObjectManipulation.DEFAULT.set(
    "MD1161833204",
    map,
    "PROCESS_NAME"
);
```

This is especially useful when session manipulation occurs during **process execution**.

***

### Summary

The **Session Manipulation Java API** enables controlled, runtime‑level data handling within ONEWEB.

Key capabilities include:

* Reading and updating session‑scoped business objects
* Supporting one‑to‑one and one‑to‑many data structures
* Modifying runtime data without immediate database persistence
* Process‑aware session manipulation
* Safe integration with CRUD and Process Runtime APIs

This API plays a critical role in **complex runtime workflows**, **process‑driven logic**, and **dynamic data handling** in the ONEWEB platform.


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