
This document describes how users interact with Active Channels for Microsoft® Internet Explorer 4.0. Details are provided on how users add and remove channels from their desktop, as well as how channel subscriptions are managed.
Introduction to Active Channels
Adding an Active Channel to the Desktop
Managing an Active Channel Subscription
An Active Channel is a Web site described by a Channel Definition Format (CDF) file. The information contained in the CDF includes the hierarchy of the Web pages and resources available for that channel, as well as a schedule recommended by the Web publisher for updating the information in the channel. This document describes the user interface associated with Active Channels, including how users can manage their channels. CDF elements corresponding to a specific feature or user interface element are indicated where applicable. For demonstration purposes, the Internet Client SDK channel is used throughout this document. This channel is available by navigating to http://www.microsoft.com/msdn/sdk/inetsdk/help/default.htm with Internet Explorer 4.0 and clicking on the Add Active Channel button. Note that some of the images and text shown for this channel are subject to change.
Note Additional information on channels and CDF files is available in Content Delivery Mechanisms, Creating Active Channels, and the CDF Reference for Active Channels.
Internet Explorer 4.0 includes a special Active Desktop item called the desktop Channel Bar. This item contains the 32W x 80H logos for all channels currently available on the user's computer. The desktop Channel Bar appears on the right side of the desktop by default and is only visible when the Active Desktop is enabled. The user can enable the Active Desktop by right-clicking the desktop and selecting the View as Web Page option from the Active Desktop menu. The desktop Channel Bar is pre-populated with channels and category folders containing groups of channels on related topics. The channel guide appearing in the desktop Channel Bar contains a list of Active Channels and is maintained by Microsoft.
Desktop Channel Bar
As the user moves the cursor onto a LOGO image in the desktop Channel Bar, the image is presented as a 3-D button and displays the channel's ABSTRACT description in a tooltip, if one is specified in the CDF file.
Users will be able to add channels from three sourcesa publisher's Web page, the Channel Guide, and pre-installed channels in the desktop Channel Bar. While browsing a Web site or a category in the Channel Guide, the user will encounter a link or image button that can be clicked to add the Active Channel to the desktop Channel Bar and optionally subscribe to the channel. Information on how to place an Add Active Channel logo button is available in the Creating Active Channels documentation.
The Add Active Channel Button
Immediately after users click the Add Active Channel button, the Add Channel dialog box is displayed. This gives users three options for how the channel will be setup on their computer, as follows:
This option simply adds the channel to the desktop Channel Bar. When the user clicks on the channel logo, the browser launches into full screen view and loads the URL specified by the CHANNEL element in the CDF file. Adding a channel with this option is similar to creating a favorite. The user can view the channel while he or she is online, but no content is available for offline viewing and the content is not updated on the user's computer. Therefore, users are not notified when changes occur on this site.
This option updates the channel's CDF file according to a schedule set by the publisher with the SCHEDULE element in the CDF file, unless overridden by the user with a custom schedule. The user is notified that content has been updated with a "gleam" placed over the logo in the desktop Channel Bar and on the icons representing the individual content items. A user can optionally be notified of changes through e-mail. With this option, the channel's navigable hierarchy, or sitemap, is available for offline viewing, if one exists. However, clicking on any of the channel's content requires a connection to the Internet because the content wasn't previously downloaded into the cache.
A channel with this option set will place the channel's sitemap (if one exists) and the actual content of the channel in the user's cache. Similar to the second option, this type of subscription is updated according to the publisher's schedule unless the user overrides it. Therefore, the user can browse through the entire channel at any time, even when not connected to the Internet, and view the latest information since the last channel update. However, some content may not be available for offline viewing if the publisher has specified the PRECACHE="No" attribute on one or more items.
Add Channel Dialog
If a channel subscription is selected, the user can press the Customize button to run the Channel Subscription Wizard. This allows the user to modify the settings for the channel subscription. The first dialog box allows the user to specify whether the entire contents referenced in the CDF file should be downloaded, or just the main channel page. If the user chooses the latter, then clicking any item exposed in the sitemap other than the main channel page would require a connection to the Internet, as the resources will not be available in the local cache.
Channel Subscription Wizard Content Selection
Next, the user can select how content update notifications will be handled. By default, Internet Explorer uses the visual "gleams" to indicate new content. However, e-mail notification can also be sent to the user when the content is updated.
Channel Subscription Wizard Notifications
The final property set in the channel customization wizard is the update schedule for the CDF file and/or content, depending on the type of subscription selected. The user can select either daily, weekly, monthly, or the publisher's recommended update schedule option. If no recommended schedule exists in the CDF file, the default schedule is "Daily."
Channel Subscription Wizard Schedule
If the user connects to the Internet through a modem, the user must check the "Dial as needed..." box to enable the automatically scheduled updates when the user is offline. Modem users who don't enable the "Dial as needed..." option will only receive channel updates if the update occurs while they are online. Channels can be manually updated at any time by performing one of the following actions:
At this point, the user will return to the original Add Channel dialog box presented after the initial Add Active Channel button was pressed. Once the user clicks the OK button, the channel subscription is updated, if one exists, and the browser opens the channel in full screen view, as shown below.
Full Screen View with Channels Pane
The full screen view of the browser includes a toolbar at the top of the screen with a smaller set of navigational controls and a status bar. The auto-hiding Channels Explorer Bar is displayed on the left side of the screen when the channel is initially loaded and whenever the user places the cursor at the left edge of the screen. On screens 1024 x 768 and larger, the Channels Explorer Bar is continuously displayed by default. This behavior can be achieved on smaller screens by clicking on the "pin" icon in the right-hand side of the bar. This disables the autohide feature until the pin is clicked again. Note that when viewing a channel in a normal browser window without full screen view enabled, the Channels Explorer Bar does not autohide. The tooltip shown in the picture below is specified in the channel's CDF file using the ABSTRACT element, and it is displayed when the user pauses the mouse over that item.
Channel Hierarchy
Notice that the hierarchy of the channel just added is now expanded to show the first level of subchannels and items. Clicking on a subchannel further expands the current channel hierarchy displayed in the sitemap to show its contents. The user can select any of these exposed items to navigate to the associated Web page, similar to using the Favorites menu. When the user selects a different channel, the previously selected channel hierarchy contracts in the channel pane, and the newly selected one expands to show any items and subchannels it contains. The Channels Explorer Bar also replaces the previous channel's logo with the title of the channel in plain text, and it now displays the logo of the newly selected channel. The examples below show the user switching to the News and Technology category folder and then back to the Internet Client SDK channel.
Switching to a Category Folder
Switching Back to the Internet Client SDK Channel
Although the full screen view shown above is the default viewing mode for Active Channels, users can navigate through a channel in a normal browser window. To toggle the full screen view on or off, users can either click on the Full Screen button located on the standard button toolbar or select Full Screen on the View menu.
Channel in Normal View
Channel publishers can designate Web pages as screen saver pages in CDF files by setting the VALUE="ScreenSaver" attribute on the USAGE element. These pages rotate through the Internet Explorer screen saver with equal display times while the computer is idle. By default, the screen saver page from each channel is shown for 30 seconds before moving on to the next channel.
Active Channel Screen Saver
The user can move the mouse without closing the Channel Screen Saver page. This allows users to navigate to a URL by clicking on HTML links displayed on the screen saver page. Web publishers can use the Channel Screen Saver page to provide users with all the latest information because the screen saver is a URL that is downloaded to users' computers on a regular basis. To close the Channel Screen Saver, the user can press any key or click the "x" appearing in the autohide toolbar in the upper-right hand corner of the screen. This toolbar also allows users to change the screen saver properties shown below.
Active Channel Screen Saver Properties
Note If the Channel Screen Saver is not enabled when subscribing to a channel containing a screen saver page, users will be asked if they would like to enable it.
Now that the channel has been added to the user's computer, a logo image representing a shortcut to the Internet Client SDK channel has been placed just below the channel guide in the desktop Channel Bar.
Desktop Channel Bar
When the user clicks the Internet Client SDK logo button, the browser launches the channel's associated URL into Internet Explorer's full screen view. Channels can also be accessed by clicking the "View Channels" icon in the quick-link launch bar located in the task bar next to the Start button. Clicking this icon opens the browser in full screen view and loads the most recently viewed channel.
To remove a channel, the user simply right-clicks on an icon or logo image representing the channel and selects Delete from the context menu. Items representing a channel can be found in the following places:
This will remove the logo images from the desktop Channel Bar and the Channels Explorer bar, as well as remove the channel's subscription (if any) from the \WINDOWS\Subscriptions folder.
Channel subscriptions provide a way for users to automatically receive updated information about a channel. Users can choose to subscribe to just the hierarchy of the channel or to have the content delivered as well. The Subscription tab provides a summary of the channel subscription information and offers the option of unsubscribing from the channel. If the user chooses to unsubscribe, the channel remains in the desktop Channel Bar as a link to the main channel page, but no content is updated in the local cache with a CDF file. This is equivalent to selecting the first option, "just add to my channel bar", when adding a channel.
To view or modify a channel subscription, hold down the right mouse button on an icon or logo image representing a channel and select Properties from the context menu. Channel icons can be accessed by selecting the "Manage Subscriptions..." option from the Favorites menu, and logos can be accessed from the desktop Channel Bar or Channels Explorer Bar.
Subscription Properties
The Receiving tab on the subscription properties allows users to modify the type of subscription (with or without content), e-mail notifications, and login information for the associated Active Channel.
Receiving Properties
When channels with full subscriptions are actually updated, the default behavior is to download all content specified in a channel to the local cache, along with designated screen saver files specified in the CDF. The type of content downloaded by default includes the HTML page (or URL) indicated in the ITEM element of the CDF file and any image files it displays. However, users can manage the amount and type of data being sent to their computer by selecting the "Advanced..." button on the Receiving tab. The Advanced Download Options dialog box allows users to enable and disable whether images, sounds, video, Java applets, and ActiveX Controls used in an HTML page automatically get downloaded to their local cache.
Advanced Download Options
Web publishers can require files to be downloaded as part of the channel by specifying each one in an ITEM element, regardless of the Advanced Download Option settings. If the required resource is not intended to be exposed in the hierarchy displayed in the Channels Explorer Bar, the USAGE element should be included as a child element of the item with its value set to "None."
The Schedule tab allows users to modify the schedule on which the channel's CDF file and content (for full subscriptions) is updated. Besides the publisher's recommended schedule, users can select a standard daily, weekly, or monthly schedule. The "New..." and "Edit..." buttons are provided for creating custom schedules.
Schedule Properties
Note Modem users must check the "Dial as needed..." check box to use the publisher's recommended schedule.
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