Using the Objects to Store Content Data

The following example demonstrates the rudimentary use of the Active Channel Server COM objects to store channel information.  This example demonstrates

• creating a Project object
  
  
• adding Item objects  to the top level Channel object
  
  
• adding logos to the project
  
  
• listing URL and bibliographic information about the items and channels
  
  
• Generating the CDF string defined by the hierarchy of objects and their properties

As a starting point, assume the CDF listed below is the desired CDF output.  This CDF defines a "Color" channel that has most of the standard elements, including <LOGO>, <SCHEDULE>, <CHANNEL>, and <ITEM>.  A VBScript script is listed next that would create the object-model representation of this information.  Once created, the information is saved, and the CDF is then generated.

Sample "Color" Channel CDF Text

<?XML version="1.0"?>

<CHANNEL HREF="http://www.mysite.com/Channel/homepage.htm"
    BASE="http://www.mysite.com/Channel/">
   <TITLE>Sample "Color" Channel</TITLE>
   <ABSTRACT>The sample color channel contains a red, green, and blue page for viewing.</ABSTRACT>
   <LOGO HREF="logo_big.gif" STYLE="IMAGE-WIDE"/>
   <LOGO HREF="logo_med.gif" STYLE="IMAGE"/>
   <SCHEDULE STARTDATE="1997-09-23">
      <INTERVALTIME DAY="1" />
      <EARLIESTTIME HOUR="2" />
      <LATESTTIME HOUR="6" />
   </SCHEDULE>
      <ITEM HREF="page1.htm">
      <LOGO HREF="red.gif" STYLE="ICON"/>
      <TITLE>The Red Page</TITLE>
      <ABSTRACT>This is the abstract description for the red page.</ABSTRACT>
   </ITEM>
   <ITEM HREF="page2.htm">
      <LOGO HREF="green.gif" STYLE="ICON"/>
       <TITLE>The Green Page</TITLE>
      <ABSTRACT>This is the abstract description for the green page.</ABSTRACT>
      </ITEM>
   <ITEM HREF="page3.htm">
      <LOGO HREF="blue.gif" STYLE="ICON"/>
      <TITLE>The Blue Page</TITLE>
      <ABSTRACT>This is the abstract description for the blue page.</ABSTRACT>
   </ITEM>
   <ITEM HREF="scrnsave.htm">
      <USAGE VALUE="ScreenSaver"></USAGE>
   </ITEM>

</CHANNEL>

VBScript Example That Builds a Representation of the CDF Above.

The example that follows creates a Project object and all the necessary secondary objects to represent the CDF information above.

' Using VBScript and Windows Scripting Host Runtime Env
Dim Project

Set Project = CreateObject("Push.Project")
Project.Name="ColorChannel"

' Add the logos to the project 

call Project.AddLogo("Top-Big","logo_big.gif", "IMAGE-WIDE")
call Project.AddLogo( "Top-Med","logo_med.gif", "IAMGE")
call Project.AddLogo( "Red"    , "red.gif",     "ICON")
call Project.AddLogo( "Green"  , "green.gif",   "ICON")
call Project.AddLogo( "Blue"   , "blue.gif",    "ICON")

' set up the channel

Project.Channel.HREF="http://www.mysite.com/Channel/homepage.htm"
Project.Channel.BASE="http://www.mysite.com/Channel/"
Project.Channel.Title="Sample "Color" Channel"
Project.Channel.Abstract="The sample color channel contains a red, green, and blue page for viewing."

' attach the logos to the channel itself
Project.Channel.LogoRefs.Add "Top-Big"
Project.Channel.LogoRefs.Add "Top-Med"

' set up the schedule element
Project.Channel.Schedule.Startdate=#1997-09-23#
Project.Channel.Schedule.Intervaltime=1
Project.Channel.Schedule.Earliesttime=2
Project.Channel.Schedule.Latesttime=6

' now add the items
Dim Item

' Red item
Set Item = Project.Channel.AddItem
Item.HREF="page1.htm"
Item.Title="The Red Page"
Item.Abstract="This is the abstract description for the red page."
Item.LogoRefs.Add "Red" 

' Green item
Set Item = Project.Channel.AddItem()
Item.HREF="page2.htm"
Item.Title="The Green Page"
Item.Abstract="This is the abstract description for the green page."
Item.LogoRefs.Add "Green" 

' Blue item
Set Item = Project.Channel.AddItem()
Item.HREF="page3.htm"
Item.Title="The Blue Page"
Item.Abstract="This is the abstract description for the blue page."
Item.LogoRefs.Add "Blue"

' Screensaver item

Set Item = Project.Channel.AddItem()
Item.HREF="scrnsave.htm"
Item.AddUsage "ScreenSaver" 


' Save the project  (very important!)
Call Project.Save "ColorChannels"

' write the CDF file to disk
Call Project.WriteCDFFile("c:\channels\color\color.cdf")

This example, although not very interesting, does illustrate the core features of the = Active Channel Server Objects. A more interesting use of these objects is in an Active Channel Agent script that performs a routine refresh cycle, searching the system for content that meets certain conditions for inclusion and when found, automatically updates the project with the information.