Connecting to a Web Service Using a JSON Data Adapter

Connecting to a Web Service Using a JSON Data Adapter

You can configure a data adapter to connect to a REST web service. This mechanism is supported by the JSON and XML data adapters and supports the PUT, POST, and GET verbs.

Web Services Configuration in the Data Adapter Dialog

In addition to the usual data adapter settings, you can configure the following for a JSON or XML adapter that connects to a web service:

Data URL – Base URI for the request.
Username and Password – Credentials for web services that require authentication.
Request method – The method to use for the data adapter. Supported methods are GET, POST, and PUT.
URL Parameters tab – Parameters to append to the URI.
POST/PUT Parameters tab – Parameters to send in the request body.
POST/PUT Body tab – Data to send in the request body.
Headers tab – Parameters to send in the HTTP header.

The Data Adapter Tab in the Dataset and Query Dialog

When you create a report using a data adapter that connects to a web service, you see the following Data Adapter tab in the Dataset and Query dialog:

Data Adapter tab

This tab lets you configure the following information for the data adapter:

Data URL – Base URI for the request.
Username and Password – Credentials for web services that require authentication.
Request method – The method to use for the data adapter. Supported methods are GET, POST, and PUT.
URL Parameters tab – Parameters to append to the URI.
POST/PUT Parameters tab – Parameters to send in the request body.
POST/PUT Body tab – Data to send in the request body.
Headers tab – Parameters to send in the HTTP header.
The following additional information is shown:
– The URL parameter in the data adapter has been associated with an HTTP parameter in the report. The name of the report parameter is shown to the right.
– The URL parameter in the data adapter has a default value.

Example of Connecting to a Web Service

The example in this section uses a GET request to retrieve information from the National Oceanic and Atmospheric Administration (NOAA) and display it in a report. The service shows weather from a location. An example query that you would enter in your browser would be:

https://www.ncdc.noaa.gov/cde-web/api/v2/data?datasetid=GHCND&locationid...

where [token] is the web services token you request in the first step below.

This example uses a public API from a third party to generate a report. This API is not controlled by TIBCO, Inc. and is subject to change without notice.

The overall steps are:

Create a data adapter that will construct the web services request. You can enter the following components of your request: a base URL, a header, and HTTP parameters.
Create a report that uses the data adapter and discover fields.
Add HTTP parameters to the report and connect them to the parameters in your adapter.

Request a web services token:

Before you can use this example, you must get a web services token from the NOAA at https://www.ncdc.noaa.gov/cdo-web/token. Follow the directions on this page to have a token sent to your email. If you do not receive your token, check your spam folder.

Create the data adapter:

1. Click on the main toolbar OR right-click a project in the Project Explorer and select New > Data Adapter.
2. In the DataAdapter File window, choose the project where you want to save the data adapter file. This should be the project that contains the report(s) you want to use with your data adapter.
3. Enter a name for your adapter, for example NOAA adapter, and click Next.

The Data Adapters Wizard is displayed.

4. Select the data adapter type that corresponds to the type of information the web service provides. This example uses JSON.
5. Click Next.
6. Enter a name for your adapter. This name is used when you select an adapter for a report.
7. In the File/URL field, enter the base web services request for your data. You want this request to be general enough that you can use it for multiple datasets and reports, but you also want it to contain as much reusable information as possible. For example, for NOAA, you might enter this request:

https://www.ncdc.noaa.gov/cdo-web/api/v2/data?datasetid=GHCND

8. Select Use the report JSON expression when filling report.
9. Click Options to open the Http Connection Options dialog to configure additional request parameters. You can later configure these parameters in your report.

HTTP Connection Options

The following parameters are available:

     Username and Password (optional) – The username and password to use if your location requires authentication. For this example, leave them blank.
     Request Type – For this example, select GET to retrieve data from the web service.
     To add a parameter to the request URL, click Add in the URL Parameters tab. Enter the name and value of your parameter in the Parameter dialog and click OK.These parameters are added to the request URL. Use the parameter names required by your web service. Later, when you create a report using this data adapter, you can connect the web services parameter to a parameter in the report. In this case, the Value field is overridden by the parameter configuration in the report. For multiple parameters, add each parameter separately.

For this example, set the following parameters:

locationid: Set Name to the NOAA parameter locationid and Value to a default location in NOAA format, for example ZIP:.
startdate: Set Name to startdate and Value to the current date. (Note: The NOAA parameter startdate is optional and defaults to the current date.)
enddate: Set Name to enddate and Value to the current date. (Note: The NOAA parameter enddate is optional and defaults to the current date.)
     Click on the Http Headers tab to add headers to the HTTP request. To do this, click Add, enter the name and value of your parameter in the Parameter dialog and click OK. For this example, add the NOAA token you requested:
token: Set Name to the NOAA parameter token and Value to the NOAA key you requested previously.
10. Click OK.
11. Click Test Connection to verify the data can be received.

Using the Data Adapter in a Report

1. Create a report using a blank template and the data adapter you just created.
2. In the Dataset and Query dialog, select JSON as the language.

The right-hand side is populated with nested object names for each individual result.

Fields for JSON data

3. Enter the objects you want to use in your dataset. For this example, enter results. If you only wanted to get the datatype values for each record, you could enter results.datatype.
4. Click Read Fields to load the list of fields in the dataset.
5. To optionally preview a subset of the data, select the Data preview tab, then click Refresh Preview Data.

Data preview for JSON data

6. Click OK.

Lay out the report:

1. Select Design view.
2. For this simple report, select all the fields and drag them to the Detail band.
3. You can preview the report to see the data.

Adding HTTP Parameters to the Report

Normally, you do not want your parameters to be fixed values. You may want to use an expression or to prompt for user input. You can add HTTP input parameters in three ways:

Using the Parameters tab in the Dataset and Query dialog
Using the Outline and Properties views
Using the Data Adapter tab in the Dataset and Query dialog, with additional configuration on the Parameters tab

This section shows how to create parameters that override the parameters from the data adapter and prompt the user for data.

Configuring a Parameter using the Parameters tab in the Dataset and Query dialog

1. Right-click the root node of your report and select Dataset and Query….
2. In the Dataset and Query dialog, click the Parameters tab.
3. Click to hide the system parameters.
4. Click Add to create a new parameter.
5. Select the parameter you just created, click Editand enter the following, then click OK:
     Parameter Name – Location
     Is For Prompttrue (default)
     Class Typejava.lang.String (default)
     Default Value Expression"ZIP:94111"
6. Click to display parameter properties.
7. Select your parameter and click Add Property. A dialog displays a list of properties available for a web services data adapter.

Properties for an HTTP Parameter

8. Select URL Parameter and click OK.
9. Select the property you just created and click Edit.
10. Enter locationid to map this parameter to the locationid URL parameter in your request and click OK.
11. If you click on the Data Adapters tab, you see that the value for locationid has been set to Location.
12. Click OK to exit the Dataset and Query dialog.
13. Preview the report.
14. You are now prompted to enter a value for the location, for example, ZIP:99501. For more information about location formats, see the NOAA API documentation.
15. Click to run the report.

Configuring a Parameter Using the Data Adapter Tab in the Dataset and Query Dialog

The names and default values you set for the URL parameters in your data adapter are shown on the Data Adapter tab in the Dataset and Query dialog. You can use this tab to associate your HTTP parameter directly to a parameter in the report.

1. Display your report in design view.
1. Right-click the root node of your report and select Dataset and Query….
2. In the Dataset and Query dialog, click the Parameters tab.
3. Click Add to create a new parameter. A new parameter is created with a name such as Parameter1.
4. Click the Data Adapter tab.

For this example, you see three data adapter parameters, one of which has been mapped to the Location parameter in your report, shown with an icon .

5. Double-click the value field after enddate and click the icon that appears.
6. Select Parameter1 from the drop-down. This associates Parameter1 in the report with the enddate URL parameter in the data adapter.
7. On the Parameters tab, select Parameter1 and click Edit. You see that the evaluation time and properties have been set automatically. Enter the following and click OK:
     Parameter Name – End Date
     Default Value Expression – 2017-07-30
8. Click OK to exit the Dataset and Query dialog.
9. If you wish, you can preview the report. You are now prompted to enter a value for the end date as well as the location. Make sure the end date you enter is after the default start date you entered when you created the data adapter.
10. Click to run the report.

Configuring a Parameter Using the Outline and Properties Views

1. Display your report in design view.
2. In the outline, right-click Parameters and select Create Parameter.

A parameter is created with a generic name, such as Parameter1.

3. Right-click the parameter you just created and select Properties, or simply locate the properties view.
4. Enter the following on the Object tab:
     Name – Start Date
     Class – java.lang.String (default)
     Default Value Expression – 2017-07-15
     Is For Prompting – Selected
     Evaluation Time – Early
5. Click the Advanced tab in properties view, click Properties, then click .
6. The Properties dialog is displayed, showing options specific to a web services data source.
7. In the URL parameter field, enter the name of the URL parameter you wish to use for input, in this case, startdate.
8. Click Finish.
9. If you wish, you can preview the report. You are now prompted to enter a value for the start date as well as location and end date. Make sure the start date you enter is before the end date.
10. Click to run the report.

 

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