# Web Service Task
The **Web Service Task** is used to invoke **external web services** from within a business process.\
It supports both **SOAP Web Services** and **REST APIs**, allowing seamless system‑to‑system integration.
It is represented by a **rectangular BPMN activity node**, as shown below.
***
### Purpose
The **Web Service Task** enables a process to:
* Call external systems
* Exchange data with third‑party services
* Integrate with enterprise and cloud APIs
It is commonly used for:
* Data synchronization
* Service orchestration
* External validation and enrichment
* Microservice integration
***
### Web Service Task Configuration Overview
The Web Service Task configuration panel contains **four main tabs**:
1. **General**
2. **Business Object**
3. **Web Service Parameter**
4. **Mapping Parameter**
Each tab controls a specific aspect of service invocation.
***
### General Tab
The **General** tab defines basic metadata for the Web Service Task, including:
* Task name
* Task ID
* Description
These properties help identify the task’s purpose within the process flow.
> **Important**\
> Always click **Save Panel** to persist configuration changes.
***
### Business Object Tab
The **Business Object** tab is used to configure and map:
* **Input parameters** sent to the web service
* **Output parameters** received from the web service
This mapping allows web service responses to be reused by downstream activities.
Business Object mapping is required whenever:
* Data is passed into the service
* Data returned from the service is used later in the process
***
### Web Service Parameter Tab
In this tab, users define **how the web service is called**.
#### Core Property
| Property | Mandatory | Default | Description |
| ---------------- | --------- | ------- | ---------------------------------- |
| Web Service Type | Yes | SOAP | Web service protocol: SOAP or REST |
Depending on the selected type, either the **SOAP** or **REST** configuration panel will be displayed.
***
### SOAP Web Service Configuration
When **SOAP** is selected, users must configure the SOAP service details.
#### SOAP Properties Overview
* **Source Type**: URL or File
* **Use Environment**: Use environment variables for WSDL, credentials
* **WSDL URL / File**: Location of WSDL definition
* **XSD File** (optional)
* **Operation**: SOAP method to be invoked
* **Endpoint**: Service endpoint URL
* **Authentication**: HTTP authentication (optional)
* **Username / Password**: Credentials (supports environment variables)
#### SOAP Utilities
* **Choose WSDL** – Upload WSDL file
* **Choose XSD** – Upload XSD file
* **Get Operation** – Discover available SOAP operations
* **Get Endpoint** – Retrieve endpoint from WSDL
***
### REST API Configuration
When **REST** is selected, users must configure REST API parameters.
#### REST Properties Overview
* **Use Environment** – Load REST URL from environment variable
* **REST URL** – API endpoint
* **HTTP Type** – GET, POST, PUT, DELETE, etc.
* **Accept Header** – Expected response media type
* **Content Type** – Request payload type
* **Authentication** – Basic or IAM2
* **Username / Password** – For Basic authentication
* **Header (Key / Value)** – Additional request headers
Use **Add Row** to add multiple headers.\
Use the **Trash icon**  to remove header rows.
***
### Mapping Parameters (SOAP & REST)
Both SOAP and REST support parameter mapping via **Open Mapping Parameter**.
Clicking this button opens the **Mapping Parameter screen**, where users can map:
* Process input → Web service input
* Web service output → Process output
***
### SOAP XPath Mapping Example
SOAP responses are mapped using **XPath expressions**.
Example WSDL structure:
XPath mapping example for field **title**:
**Method 1**
```
/Operation_in/book/title
```
**Method 2**
```
//book/title
```
**Method 3**
```
//title
```
All methods produce the same result, depending on XML structure.
***
### XPath Expression Reference
| Expression | Description |
| ---------------- | ---------------------------------- |
| nodename | Selects all nodes with that name |
| / | Selects from root node |
| // | Selects nodes anywhere in document |
| . | Selects current node |
| .. | Selects parent node |
| @ | Selects attributes |
| nodename\[index] | Selects element by index |
***
### Summary
The **Web Service Task** enables powerful external integrations within ONEWEB processes.
Key features:
* Supports SOAP and REST
* Environment‑based configuration support
* Full input/output data mapping
* XPath‑based SOAP response handling
* Header, authentication, and security options
It is a core component for **enterprise‑grade integration and service orchestration** within Process Designer.
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