IBM Worklight's HTTP adapter provides access to HTTP- and HTTPS-based enterprise services and is used to invoke RESTful services and SOAP-based services using the GET, POST, PUT, and DELETE methods into the request. For the response, data can be received in the XML, JSON, and HTML formats, with the content type defined in the request.

To cover the HTTP adapter example, we will use a real-time scenario by utilizing a Flickr feed RESTful service and loading data from the live server. Later on, we will manipulate this response data to utilize and create a sample demo app for Flickr in http://www.flickr.com/services/feeds/.

To create a HTTP adapter in the Worklight project, please perform the following steps:

In the preceding code listing, var filckrFeedUrl holds the URL to call the Flickr feed from the live site and bind it with the domain that we defined in the FlickrFeedAdapter.xml file. The complete URL look like this:

http://api.flickr.com/services/feeds/photos_public.gne?id=47906772@N05&lang=en-us&format=json

Please use following link to understand the feed's URL with all the parameter definitions in detail:

http://www.flickr.com/services/feeds/docs/photos_public/

The WL.Server.invokeHttp(input) function provided in Worklight Server API is responsible for the request/response in calling services. Now that we have done our first procedure declaration and definition, it's time to test and verify the adapter's result.

Before moving on to test the adapter's result, we need to deploy our adapter to the Worklight Sever. To do that, we also need to build our adapter to make sure that the error-free code will deploy itself into Worklight Server. In order to do that, Worklight Studio provides the Deploy Worklight Adapter the option to complete this procedure with a single click. Right-click on the FlickrFeedAdapter folder under the adapter folder and navigate to Run As | Deploy Worklight Adapter, as shown in the following screenshot:

This will deploy the adapter on Worklight Server or check the console window for the deployment status in the Worklight Console section. Now our adapter is ready to invoke. Right-click on the FlickrFeedAdapter folder and navigate to Run As | Invoke Worklight Procedure. Clicking on it will open the pop-up Edit Configuration and Launch window and to invoke this, you have to select Project name, Adapter name, Procedure name, and Parameters and then click on the Run button.

After clicking on the Run button, the Invoke Procedure Result explorer window will open in the IDE to display the results. If all the steps have been followed correctly so far, then the response that the JSON data fetched from Flickr will be displayed in the explorer window, as shown in the following screenshot:

If you have followed the steps correctly, you will have an output that is similar to the preceding screenshot, which shows successful results from the Flickr feeds with your own created adapter.

IBM Worklight SQL adapter is designed to interact with any SQL data source and is used to execute plain parameterized SQL queries and stored procedures to retrieve and update data in the databases. Currently, Worklight SQL adapter supports the following databases:

The JDBC connector driver for a specific database type can be downloaded from the MySQL, DB2, and Oracle websites. The developer will have to add a specific driver jar into the server | lib folder under Worklight project directory structure to make it available to the app.

To get a clearer idea about the SQL adapter, we will include an exercise for you to authenticate a user by matching the user credentials from the database. Through this exercise, you will learn two basic things that include database connection and performing a SQL using the SQL adapter. Creating a SQL adapter's steps is very much similar to an HTTP adapter.

Before diving into the creation of a SQL adapter, we would like you to have an in-depth understanding of the SQL adapter, regarding its files and configuration elements. A SQL adapter mainly has two important files—one is the .xml file that is used to configure the data source and declare the procedures, and another is the JavaScript for the definition of the declared procedures. The .xml file has the <connectionPolicy> element under <connectivity>, which is used to configure the connection type for an adapter. For a SQL adapter, a mandatory attribute xsi:type must be set to a sql:SQLConnectionPolicy value.

The <connnectionPolicy> element provides you with two choices to connect with the database. One is the <datasourceDefinition> subelement that is used to define the data source and the other is the <dataSourceJNDIName> subelement that is used for the JNDI Name of the data source provided by the application server.

To use the <dataSourceDefinition> subelement, the following elements must be defined:

The following code listing shows us the structure of the preceding elements with their configuration:

<connectivity>
<connectionPolicyxsi:type="sql:SQLConnectionPolicy">
<dataSourceDefinition>
  <driverClass>com.mysql.jdbc.Driver</driverClass>
  <url>jdbc:mysql://localhost:3306/dbName</url>
  <user>myPassword</user>
<password>myPassword</password>
  </dataSourceDefinition>
</connectionPolicy>
<loadConstraints maxConcurrentConnectionsPerNode="5"/>
</connectivity>

Declaring the procedure in a SQL adapter is same as an HTTP adapter, where a .js file is used to define the SQL statement that executes under a procedure/function. To create a SQL statement, Worklight Server API has a WL.Server.createSQLStatement method and to invoke this SQL statement, the same Server API has the WL.Server.invokeSQLStatement function.

Later in this chapter, we will discuss both the functions in detail and implement the creation of the SQL adapter's steps.

We will assume that you already have a database setup in your machine and to use Worklight SQL adapter, we need to have a schema ready to test and run it. The following code is a SQL script for the database and table that we have used in our example:

CREATE SCHEMA `FlickrDemo`;

CREATE TABLE `FlickrDemo`. `Authentication` (
  `username` VARCHAR (50) NOT NULL,
  `password` VARCHAR (50) NOT NULL ,
`first_name` VARCHAR (45) NULL,
  `last_name` VARCHAR (45) NULL,
  UNIQUE INDEX `username_UNIQUE` (`username` ASC));

For the table data, use the following queries to prepare the record for the table that will be created:

INSERT INTO `FlickrDemo`. `authentication` (`username`,`password`,`first_name`,`last_name`)VALUES('talhaH','123456','Talha', 'Haroon' );

INSERT INTO `FlickrDemo`. `authentication` (`username`,`password`,`first_name`,`last_name`)VALUES  ('saifo', '123456','Muhammad', 'Saifuddin'),

Let's use the following steps to create a SQL adapter:

Congratulations! You have successfully created the SQL adapter. The result is retrieved as a JSON object where it is a property named isSuccessful, as shown in the preceding screenshot, pointing out that the invocation was successful and resultSet is an array of returned database records.