Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.
Comment: Migrated to Confluence 5.3

The data services feature supports scraping and extracting web information and presenting it as a service. To demonstrate the process of service-enabling a web resource, the following guide uses Yahoo Weather Forecasts to extract weather information.

First, create a configuration file with information regarding the web resource and the xslt file, which has information regarding the response. Given below are sample configuration and xslt files.

Sample Configuration File:

<?xml version="1.0" encoding="UTF-8"?>
Code Block
languagehtml/xml
<config>
 <var-def name='weatherInfo'>
  <xslt>
   <xml>
    <html-to-xml>
      <http method='get' url='http://weather.yahoo.com/'/>
    </html-to-xml>
   </xml>
   <stylesheet>
    <file path="/media/data/web/template.xsl"/>
   </stylesheet>
  </xslt>
 </var-def>
</config>

Sample XSLT File:

Code Block
languagehtml/xml
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" omit-xml-declaration="yes" indent="yes"/>
<xsl:template match="/">
  <WeatherInfo>
   <xsl:for-each select="//div[@id='myLocContainer']/ul/li">
     <Weather>
      <Region><xsl:value-of select="a/@title"/></Region>
      <Temp><xsl:value-of select="em"/></Temp>
     </Weather>
   </xsl:for-each>
  </WeatherInfo>
</xsl:template>
</xsl:stylesheet>

Follow the instructions below to create a data service. In this example we use Yahoo Weather Forecasts to extract weather information. 

1. Log on to the product's management console and select   "Data Service -> Create" under the "Main" menu.

Image RemovedImage Added

2. The "Create Data Service" page appears. Fill in the fields and click "Next" . The Data Service name is mandatory. Image Removed In this example, "Yahoo Weather Forecasts" is used to extract weather information.

Image Added

Info

Info:
For more information on Advanced Configurations in creating data servicesadvanced configurations, refer to section "   Advanced Data Service Management -> Transaction HandlingConfigurations."

3. The "Data Sources" page appears. Click on the "Add New Data Source" link and add your Data Source details. Select the data source type as "Web Data Source ".

Example 1:

You can either save the configuration to an xml and provide the file path, or can enter as an inline configuration. In example 1, we provide the sample configuration mentioned above as a file path.

Image RemovedImage Added

Example 2:

In example 2, we use an inline configuration.

Click "Save" . You have added a Data Source to your Web Service. Click "Next" to proceed.

4. The "Queries" page appears. Initially your service does not include any queries. Click on 'Add New Query' to add a new query, input/output mappings, events etc. to your Data Service. Enter query details according to the structure of the response you want.

...

In this example, we have used "Grouped By Element" , "Row Name" and "Row namespace" as follows.

Image RemovedImage Added

Click the "Add New Output Mapping" button as shown in the screenshot above to create how the output looks like. Once you have entered the output mapping details, click "Main Configuration" and then the "Save" button as follows:

Image RemovedImage Added

For information on adding validations to your input mappings in the query, if any, refer to section Input Validators.. Also, detailed information on writing queries can be found in section Data Service Queries. Once the query details are added click "Save ". You have added one query to your data service configuration. To continue, click "Next ".

5. The "Operations" page appear s. Click the "Add new operation" link to c reate an operation. Select a query to be executed when this operation is called and click Save once done. For example,

Image RemovedImage Added

6.  The Data Service configuration is done. Click "Finish" . ( You can continue to add resources by clicking the "Next" button if you like)

7. You will be navigated to the "Deployed services" page .

Image RemovedImage Added

From here, you can manage your data service. For instructions, refer to section " Service Management. " For a demonstration on service-enabling a web resources, refer to Web Resource Sample.

Excerpt
hiddentrue

Instructions to create data services using a Web resource (yahoo weather) in WSO2 products.