Using the Advanced HTTP Application

The Advanced HTTP Application provides a way to call web services directly from the touchatag Application Correlation Service (ACS), instead of from the end user’s browser. For example, it could be used to log events to a web server, such for tracking when a mobile worker visits a specific station.

Compare with Weblink App

There is a significant difference between the Advanced HTTP Application and touchatag’s popular Web Link Application.

The Web Link Application calls a URL by opening the end user’s browser, using the following workflow:

1. The end user touches a tag to his or her reader, which calls on the ACS to correlate a tag action.
2. The ACS determines that the tag is associated to a Web Link Application, and sends back the URL to the end user's system.
3. The end user's browser opens the URL sent by the ACS.

The Advanced HTTP Application calls a URL directly from the ACS, without opening the end user’s browser:

1. The end user touches a tag to his or her reader, which calls on the ACS to correlate a tag action.
2. The ACS determines that the tag is associated to an Advanced HTTP Application, and calls the URL according to how the Advanced HTTP Application has been configured.

Benefits & Limitations

The Advanced HTTP Application is better suited for security uses than the standard Web Link Application. Because the URL call is performed by the ACS rather than the end user's system, the tag holder does not know what action is being performed by the touchatag system. The standard Web Link Application opens the target site in a browser, so the end user can easily copy the URL and use it from any other system.

One limitation to the Advanced HTTP Application is that it provides little client-side feedback to the end user, such as opening a system tray message or web page to confirm the tag transaction. However, you can use touchatag to create more complex feedback scenarios such as these using touchatag developer tools and interfaces. (See Touchatag Developer Network, for more information.)

Implementation

As the name implies, the Advanced HTTP Application is intended for advanced users who are more familiar with using Internet services & protocols.

Supported HTTP Methods

The Advanced HTTP Application can assign the ACS to call any Internet-accessible URL, using either the HTTP GET or POST method. The template also allows you to provide any parameters that are required in the URL.

Implementation Steps

1. Enter a name and description for your Application configuration.
2. Select the HTTP Method required by target the web service.
3. Enter the URL of the target the web service.
4. Enter whatever key/value Parameters are required by target the web service.
   • You do not need to HTML-encode special characters (such as spaces) in the parameters.
   • Key/value pairs left blank will be removed from the application after each re-configuration.
5. Click use this app to complete Step 1 of the configurator.

Relationship to the ACS Block System

The Touchatag Technical Whitepaper introduces you to the ACS Block System. To handle Advanced HTTP Applications, the ACS uses a block called the ACS HTTP Client block. The touchatag API allows 3rd party developers to use the ACS HTTP Client block in their own custom applications. (See ACS Block System, for more information.)