tXMLRPCInput - 6.3

Talend Open Studio for Big Data Components Reference Guide

EnrichVersion
6.3
EnrichProdName
Talend Open Studio for Big Data
task
Data Governance
Data Quality and Preparation
Design and Development
EnrichPlatform
Talend Studio

Function

Calls the defined method from the invoked RPC service, and returns the class as defined, based on the given parameters.

Purpose

Invokes a Method through a Web service and for the described purpose

tXMLRPCInput Properties

Component family

Internet

 

Basic settings

Schema and Edit Schema

A schema is a row description, it defines the number of fields that will be processed and passed on to the next component. The schema is either Built-in or remote in the Repository.

Since version 5.6, both the Built-In mode and the Repository mode are available in any of the Talend solutions.

Click Edit schema to make changes to the schema. If the current schema is of the Repository type, three options are available:

  • View schema: choose this option to view the schema only.

  • Change to built-in property: choose this option to change the schema to Built-in for local changes.

  • Update repository connection: choose this option to change the schema stored in the repository and decide whether to propagate the changes to all the Jobs upon completion. If you just want to propagate the changes to the current Job, you can select No upon completion and choose this schema metadata again in the [Repository Content] window.

In the RPC context, the schema corresponds to the output parameters. If two parameters are meant to be returned, then the schema should contain two columns.

 

Server URL

URL of the RPC service to be accessed

 

Need authentication / Username and Password

Select this check box and fill in a username and password if required to access the service.

 

Method Name

Enter the exact name of the Method to be invoked.

The Method name MUST match the corresponding method described in the RPC Service. The Method name is also case-sensitive.

 

Return class

Select the type of data to be returned by the method. Make sure it fully matches the one defined in the method.

 

Parameters

Enter the parameters expected by the method as input parameters.

Global Variables

ERROR_MESSAGE: the error message generated by the component when an error occurs. This is an After variable and it returns a string. This variable functions only if the Die on error check box is cleared, if the component has this check box.

NB_LINE: the number of rows processed. This is an After variable and it returns an integer.

A Flow variable functions during the execution of a component while an After variable functions after the execution of the component.

To fill up a field or expression with a variable, press Ctrl + Space to access the variable list and choose the variable to use from it.

For further information about variables, see Talend Studio User Guide.

Usage

This component is generally used as a Start component. It requires to be linked to an output component.

Log4j

If you are using a subscription-based version of the Studio, the activity of this component can be logged using the log4j feature. For more information on this feature, see Talend Studio User Guide.

For more information on the log4j logging levels, see the Apache documentation at http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/Level.html.

Limitation

n/a

Scenario: Guessing the State name from an XMLRPC

This scenario describes a two-component Job aiming at using a RPC method and displaying the output on the console view.

  • Drop the tXMLRPCInput and a tLogRow components from the Palette to the design workspac.

  • Set the tXMLRPCInput basic settings.

  • Define the Schema type as Built-in for this use case.

  • Set a single-column schema as the expected output for the called method is only one parameter: StateName.

  • Then set the Server url. For this demo, use: http://phpxmlrpc.sourceforge.net/server.php

  • No authentication details are required in this use case.

  • The Method to be called is: examples.getStateName

  • The return class is not compulsory for this method but might be strictly required for another. Leave the default setting for this use case.

  • Then set the input Parameters required by the method called. The Name field is not used in the code but the value should follow the syntax expected by the method. In this example, the Name used is State Nr and the value randomly chosen is 42.

  • The class has not much impact using this demo method but could have with another method, so leave the default setting.

  • On the tLogRow component Component view, check the box: Print schema column name in front of each value.

  • Then save the Job and press F6 to execute it.

South Dakota is the state name found using the GetStateName RPC method and corresponds the 42nd State of the United States as defined as input parameter.