What is a Dispatcher Application?

A Dispatcher application is written to run under the components of the Application Dispatcher. Each application consists of two parts:

an input component (HTML portion)

The input component is the HTML-based user interface to the Dispatcher application. It provides the mechanism for a user to submit a processing request. This mechanism can be an HTML form that the user completes and submits, a hypertext link, or an inline image. Regardless of the mechanism used, it must minimally send the following information to the Broker (the CGI program):

• the ID for the service that should be used to process the request (passed in the _SERVICE field)
• the name of the program that the Application Server should execute (passed in the _PROGRAM field).

a program

The Application Server runs the program to fulfill the request. This program must be designed to accept information from the Broker. This is done through the pairing of names and values that are embedded in the HTML code. See Understanding Name/Value Pairs. The program can be any of the following, but must reside in a location defined as an application library:

• a SAS program (an external file with a .sas extension)
• a source entry (a catalog entry with a .source extension)
• a compiled SCL entry (a catalog entry with a .scl extension)
• a compiled macro (a catalog entry with a .macro extension).

The Sample Applications

The download packages include sample applications to help you understand how to create your own applications. You can also use these applications to ensure that you installed and configured the Application Dispatcher correctly. The input component for each sample application is contained in the Broker package, and the program component is packaged with the Application Server.

The following table lists the samples provided:

Title	Files	Description
Hello World	hello.sas, hello.html	This sample displays "Hello World" in the user's browser. It is a simple program and makes a good installation test.
Display a Data Set	dataset1.sas, dataset1.html	This sample formats a SAS data set as an HTML table. The program uses the HTML Data Set Formatter to format the data set.
Display a Data Set with Where Clause and Sum Variables	dataset2.sas, dataset2.html	This sample formats a SAS data set as an HTML table and provides subsetting and sum features. The program uses the HTML Data Set Formatter to format the data set. This sample requires Release 6.12 of SAS software.
Frequency Procedure	freq.sas, freq.html	This sample formats SAS Frequency procedure output. The program uses the HTML Output Formatter.
Animated GIF	gifanim.sas, gifanim.html	This sample produces an animated GIF graphic. This requires Release 6.12 of SAS/GRAPH software and the SAS GIF animation driver.
Pie Chart	grphics.sas, grphics.html	This sample creates a static pie chart from the data in a SAS data set. This requires Release 6.12 of SAS/GRAPH software.
Print of Data Set	output.sas, output.html	This sample prints the values in a SAS data set. It requires the HTML Output Formatter.
List of Macro Variables Using HTML Output Formatter	showvars.sas, vartable.sas, showvars.html	This sample creates a list of the macro variables generated by name/value pair data using PROC SQL. This sample uses one of two programs based on the user's selection. The output from one program is PROC SQL output marked up by the HTML Output Formatter. The output from the other program is an HTML table produced by the HTML Data Set Formatter.
SAS Explorer	websamp catalog, xplore.html, xptext.html	This sample uses HTML frames so it requires two HTML files as input. Point your browser at xplore.html to start this application. This sample application provides an explorer interface to SAS libraries and their contents. Use it to browse data sets, catalogs, catalog entries, perform drill-down on PROC SUMMARY data sets, and even download data sets as comma-separated value files directly into your spread sheet program!
Tabulate Procedure	tabulate.html, sample.tabulate.sas	This sample illustrates the unique data analysis capabilities of the Application Dispatcher. The HTML form provides options that perform different tabulations of the same set of data.

The source code for each of the samples above has been provided to you. This should assist you in learning more about the Application Dispatcher and designing your own applications.

All the sample application HTML files use FORM tags with the ACTION= attribute set to /cgi-bin/broker (UNIX) or /cgi-bin/broker.exe (Windows). If you did not install the Application Broker CGI program in the Web server's /cgi-bin directory or had to rename the Broker, you must edit the .html files and supply the correct value for your site before they will work.