Pushing Web Content to BlackBerry Wireless Devices

            

            Deploying and enabling a web-based application on a BlackBerry wireless device allows for reduced development time by not creating a BlackBerry application. A Browser Push differs from a BlackBerry client push application as there is no requirement to develop a client to reside on the device. There are four types of Browser Push that can be sent to the BlackBerry wireless device.

1. Browser Channel Push
2. Browser Channel Delete Push
3. Browser Content Cache Push
4. Browser Message Push

Browser Channel Push

A Browser Channel Push sends a web page and two icons to the BlackBerry wireless device. The web page is stored in the cache of the BlackBerry Browser, and an icon is shown on the home screen of the device. An unread icon can be specified so that when a new Browser Channel Push arrives to the device, it will display the unread icon. After the user has opened and visited the page, the read icon is shown. This provides the user with a visual indication as to when a page has been updated. It's useful for a news service so that users are aware of when new data has arrived. The icons can even change with every push allowing an application to continually push different icons. This would be useful for a weather application updating the current weather conditions.

Browser Channel Delete Push

A Browser Channel Delete works in a similar, but opposite fashion of the Browser Channel Push. It will remove an icon on the BlackBerry Home screen that has been sent via a Browser Channel Push. Icons initiating from a Browser Channel Push can also be removed from the device itself.

Browser Content Cache Push

Browser Content Cache Push is the most discreet type of Browser Push. A Browser Content Push will push a web page to the BlackBerry wireless device and store it in the BlackBerry Browser's cache. The user is not informed in any way when this push takes place, or when the page has been updated.

Browser Message Push

Instead of creating an icon on the home screen of the BlackBerry wireless device, a Browser Message Push will arrive in the Inbox on the device. When the user opens the message, the default browser on the device is launched then opens the page. Unlike the Browser Channel Push or Browser Content Push, the web page is stored as a browser message instead of in the BlackBerry Browser's cache. This means that the page will be available until the message is deleted. It will not be removed from the BlackBerry Browser cache when other events (browsing, cache clear) take place. The message created from a Browser Message Push is not sent to, and will not appear in, a user's Inbox on their desktop. It is sent directly to the device.

How to push

Push applications can be created using any development language that is able to initiate a network connection and perform an HTTP post. A post to the BlackBerry MDS Server handles the delivery of the push to a BlackBerry wireless device. The post is made up of the standard html request headers, a few unique Browser Push headers and the web page being pushed (it is not required to send the web page when performing a Browser Channel Delete Push). The following additional http request headers are required for a Browser Push to take place.

 

Required

X-RIM-Push-Title
X-RIM-Push-Type

Optional

X-RIM-Push-Channel-ID
X-RIM-Push-UnRead-Icon-URL
X-RIM-Push-Read-Icon-URL

"The X-Rim-Push-Title" header holds the title that will appear on the home screen of the device for a Browser Channel Push, or in the subject of the message of a Browser Message Push. The "X-RIM-Push-Type" header holds the value that represents the type of push being sent. Possible values are:

• Browser-Channel
• Browser-Message
• Browser-Content
• Browser-Channel-Delete
  

The "X- RIM-Push-Channel-ID" header contains the URL of the page to be pushed to the device. This is not required when performing a Browser Message or Browser Content push. The "X-RIM-Push-UnRead-Icon-URL" and "X-RIM-Push-Read-Icon-URL" are optional headers that specify the URL of the icons to be used for a Browser Channel Push. If these are not specified then the default Browser Channel Push icons are used. These two headers are not required for Browser Message, Browser Content or Browser Channel Delete Push and may be omitted.
The page that is to be pushed is submitted once the headers are sent. It is recommended that this page resides on a web server, although it is not required. If it is not located on a web server, a user would be unable to refresh the page. If the page has been removed from the BlackBerry Browser cache (if a Browser Channel or Browser Content Push was used) they would be unable to view it. It is not required to send the actual page when performing a Browser Channel Delete.

Sample Java Push Application

           A sample Java based push application is included and documented with the BlackBerry JDE. The BlackBerry JDE is available in the JDE installation path: “$JDE_HOME$\samples\com\rim\samples\server\httppushdemo”

Sample Php Push Application

A sample php push application can be downloaded from this URL http://na.blackberry.com/eng/devjournals/resources/journals/jan_2005/phpPush.zip