Table Of ContentPraise from the Experts
“While building SAS/IntrNet applications, I would like nothing better than to have someone with
the skills of Don Henderson looking over my shoulder. Other than some SAS-L posts and a few
personal e-mail messages, this desire went unrealized. That was until I read Don’s book, Building
Web Applications with SAS/IntrNet®: A Guide to the Application Dispatcher.
“This book picks up where SAS documentation leaves off. It shows how to increase the
functionality of the SAS/IntrNet Application Dispatcher to solve problems commonly
encountered when building Web-based SAS applications. This book also supplies a host of ‘best
practices’ that can help keep one from creating future difficulties.
“An example of the gems that Don has unearthed is the INVSESS option. This option allows
developers to implement friendlier responses to failed attempts to reconnect to a session. Along
with techniques to refresh long-running requests, this book shows how to partially overcome the
problem of user sessions that time-out from user inattention.
“One of the most helpful chapters is Chapter 11, “Tools and Techniques for Debugging.” One
especially useful tip is to seed programs under development with %testPrint macros to
conditionally print intermediate results. This chapter also provides good guidance on how to run
Application Dispatcher programs in a stand-alone mode.
“In my opinion, this is a must-have book if one is responsible for creating or maintaining Web-
based SAS applications.”
Michael Davis
“At long last we have a comprehensive book on the intricacies of SAS/IntrNet programming! Don
Henderson has written the definitive, authoritative book on how to develop SAS/IntrNet
applications so that you can easily host your SAS programs on the Web. There is so much
information packed into this book that you will find something that you did not know in every
chapter. Though I have been working with SAS/IntrNet for many years, I was amazed at the
volume of information that I was not aware of.
“There are several chapters of this book that will allow you to recoup the book’s purchase price,
almost immediately. Chapter 7, “Various Techniques to Generate HTML,” is a case in point. It
takes you through increasingly advanced material, moving from using simple PUT/FILE
statements, to extending the Output Delivery System to the Web, to using SCL submit blocks, to
including HTML from external sources, to using SAS Server pages, and finally to using design-
time controls. All of these techniques have great merit; and this chapter explains how and when to
use them while providing great examples. This chapter will save you hours of research and
development time.
“Another chapter that would have saved my staff at least a week’s worth of work is Chapter 19,
“Handling On-Demand Long-Running Requests.” Many organizations face the unenviable
prospect of having to offer Web-based reports or analysis against large, complicated data sources
that end up as long-running SAS jobs. In doing so, one cannot expect Web users to sit idly by,
wondering when their output will arrive as the minutes tick by. This chapter provides two specific
techniques for spawning asynchronous SAS batch jobs, behind the scenes, to produce result sets.
The first technique launches the batch job, and then e-mails the result set to the user when the
batch job completes. The second technique provides the user with a status page in their browser
that is continuously updated as each batch job step completes, and then overlays the status page
with the final output when it becomes available. Both techniques are clearly described and include
easy-to-follow examples.
“Singling out specific chapters for comment is hard, because all of the chapters in this book have
significant tips, insights, and well-explained examples. It is obvious to me that there will not be
another book published about SAS/IntrNet software, because Don has covered everything there is
to say about the topic in this one great publication. But, then again, one would expect no less from
one of the original creators of SAS/IntrNet software!”
Michael A. Raithel
Westat
“The Paris Herald Tribune once published a satirical column by Art Buchwald describing a
mythical American tourist who visited Paris and ran a ‘four-minute Louvre.’ The tourist touched
all the must-see bases—the Venus de Milo, the Mona Lisa, and the Winged Victory of
Samothrace—making excellent time Buchwald wrote, ‘under perfect conditions, with a smooth
floor, excellent lighting, and no wind.’
“Superficial involvement with substance is something one can poke fun at, but it has no place in
serious matters. There is no way one could race through Don Henderson’s new book about how to
use the Application Dispatcher in SAS/IntrNet. This is material that demands close, patient, and
studious attention.
“This book reveals two characteristics of the author himself. First, he is a person who willingly
gives away his own know-how, sharing highly valuable insights with anyone who cares to listen.
Second, he is someone who is able to master advanced coding techniques easily and apply that
mastery to solving complex coding problems. Any programmer who works with SAS/IntrNet will
feel a sense of indebtedness to Don for making life easier.
“This book, which could have been subtitled Making the Most of SAS/IntrNet, makes it easy to
realize that the software has tremendous depth and is up to the job of dealing with practical coding
requirements. This shouldn’t astonish us. After all, SAS software in general has continued to
evolve and take on enhanced capabilities. Thus, to understand the Application Dispatcher, one
must make the same kind of effort that is involved in learning ODS or SAS/GRAPH, for example.
Don challenges the reader to do just that. There is no fluff here, only solid meat. Each paragraph,
each example, contains important information that a reader must digest slowly and carefully.
“This text is so educational that it really ought to become material for a new course offered by
SAS. Each chapter contains examples that could be converted easily into exercises. In any form,
Don’s masterful work will help SAS programmers to become better and stronger.”
Jim Sattler, President
Satmari Software Systems, Inc.
Building Web
Applications
SAS/IntrNet
with ®
A Guide to the
Application Dispatcher
Don Henderson
The correct bibliographic citation for this manual is as follows: Henderson, Don. 2007. Building Web Applications
with SAS/IntrNet®: A Guide to the Application Dispatcher. Cary, NC: SAS Institute Inc.
Building Web Applications with SAS/IntrNet®: A Guide to the Application Dispatcher
Copyright © 2007, SAS Institute Inc., Cary, NC, USA
ISBN 978-1-59994-189-9
All rights reserved. Produced in the United States of America.
For a hard-copy book: No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in
any form or by any means, electronic, mechanical, photocopying, or otherwise, without the prior written permission
of the publisher, SAS Institute Inc.
For a Web download or e-book: Your use of this publication shall be governed by the terms established by the
vendor at the time you acquire this publication.
U.S. Government Restricted Rights Notice: Use, duplication, or disclosure of this software and related
documentation by the U.S. government is subject to the Agreement with SAS Institute and the restrictions set forth in
FAR 52.227-19, Commercial Computer Software-Restricted Rights (June 1987).
SAS Institute Inc., SAS Campus Drive, Cary, North Carolina 27513.
1st printing, March 2007
SAS® Publishing provides a complete selection of books and electronic products to help customers use SAS software
to its fullest potential. For more information about our e-books, e-learning products, CDs, and hard-copy books, visit
the SAS Publishing Web site at support.sas.com/pubs or call 1-800-727-3228.
SAS® and all other SAS Institute Inc. product or service names are registered trademarks or trademarks of SAS
Institute Inc. in the USA and other countries. ® indicates USA registration.
Other brand and product names are registered trademarks or trademarks of their respective companies.
Contents
Preface xi
Acknowledgments xiii
Part 1 An Introduction to SAS/IntrNet
Software
Chapter 1 Overview of SAS/IntrNet and Related
Technologies 3
1.1 Is the Application Dispatcher a Good Fit? 4
1.2 Components of SAS/IntrNet Software 5
1.2.1 The Application Dispatcher 5
1.2.2 SAS Design-Time Controls 5
1.2.3 Xplore Sample Web Application 6
1.2.4 htmSQL 6
1.2.5 SAS/CONNECT Driver for Java 6
1.2.6 SAS/SHARE Driver for JDBC 6
1.2.7 Tunnel Feature 7
1.3 Other SAS Web Components and Technologies 7
1.3.1 The Output Delivery System 7
1.3.2 The Web Publishing Tools and Related Macro Tools 8
1.3.3 SAS AppDev Studio, a SAS Applications Development
Environment 9
1.3.4 SAS®9 Business Intelligence Platform 9
1.4 Industry Components 12
1.4.1 Scripting Languages 12
1.4.2 Dynamic HTML 15
1.4.3 Web Services 16
1.5 Component-Based Architectures 16
1.6 Terminology 18
iv Contents
Part 2 How the SAS/IntrNet Application
Dispatcher Works
Chapter 2 Overview of the Application Dispatcher
Process Flow 23
2.1 Introduction 23
2.2 Application Broker—Application Server Process Flow 24
2.3 Process Flow Including the Load Manager 25
2.4 Performance Benefits of Using the Load Manager 27
Chapter 3 The Application Broker and the Load
Manager 31
3.1 Introduction 31
3.2 Specifying Additional HTML Output 33
3.3 Defining the Load Manager 34
3.3.1 The Load Manager Command 34
3.4 Defining the SAS Application Servers 35
3.4.1 Socket Servers 35
3.4.2 Pool Servers 37
3.4.3 Launch Servers 39
3.5 Application Broker Process Flow 40
3.5.1 Load Manager Administrative Functions 46
Chapter 4 The Application Server 47
4.1 Introduction 47
4.2 SAS Application Server Executives 49
4.3 Application Server Sessions 50
4.3.1 ODS and Sessions 50
4.4 PROC APPSRV 51
4.4.1 TCP/IP Port 51
4.4.2 Assigning Libraries 51
4.4.3 Initiating and Terminating Requests 54
4.5 Application Server Process Flow 55
4.5.1 Application Server Functions Available to the Executing
Program 60
4.5.2 Application Server Clean-Up Processing 60
Contents v
Chapter 5 Communicating with the Application
Dispatcher 63
5.1 Introduction 63
5.2 Name/Value Pairs Defined by the User’s Request 64
5.2.1 _program: The SAS Program to Execute 64
5.2.2 _service: The Application Server to Process the Request 65
5.2.3 _debug: The Output to Display 65
5.2.4 Program-Specific HTML Name/Value Pairs 68
5.3 Name/Value Pairs Defined by the Application Broker 72
5.3.1 Application Broker Administrative Fields 72
5.3.2 Environment Variables 73
5.3.3 Installation Dependent Fields 74
5.4 Name/Value Pairs Defined by the Application Server 76
Part 3 Developing Application
Dispatcher Programs
Chapter 6 Methods You Can Use to Access and
Reference Input Parameters 81
6.1 Introduction 81
6.2 Accessing Parameters as Macro Variables 82
6.2.1 Using and Referencing the Multiple Values for a Single
Parameter (the Suffix Variables) 85
6.2.2 Using the APPSRV_UNSAFE Function 87
6.3 Accessing Parameters in SCL Programs 91
Chapter 7 Various Techniques to Generate HTML 94
7.1 Introduction 94
7.1.1 The Problem with Generating Valid HTML 95
7.2 Simple PUT and FILE Statements 96
7.2.1 The generateFormTag and generateInputTag Sample
Macros 101
7.3 Extending the Output Delivery System 102
7.3.1 FORM Tags Via TITLE and FOOTNOTE Statements 102
7.3.2 Character Variables with HTML Form Text 105
7.4 SCL Submit Blocks 107
7.5 Including Static HTML from External Sources 110
7.5.1 A Macro Tool to Include External HTML 114
vi Contents
7.6 SAS Server Pages 116
7.6.1 The SAS Server Page Macro 116
7.6.2 Sample Server Page: List Libraries 118
7.6.3 A Macro to Generate Data-Driven SELECT Tags 119
7.6.4 Sample Server Page: List the Data Sets in the Selected
Library 121
7.6.5 Sample Server Page: List the Variables in the Selected Data
Set 122
7.6.6 A Macro to Generate Checkboxes for Variables in a SAS
Data Set 124
7.6.7 A Program to Page Through the Selected Data Set 125
7.7 SAS Design-Time Controls 127
Chapter 8 Creating Pages with Mixed and Alternative
Content Types 131
8.1 Introduction 131
8.2 Defining the Content Type to Be Generated 132
8.2.1 Other Headers: Selected Examples 132
8.3 Generating Pages with Other Content Types 135
8.3.1 Creating a Comma-Separated Values File 136
8.3.2 Downloading Reports and Results into Microsoft
Excel 137
8.3.3 Generating Content for Printing 138
8.3.4 Generating Multiple Output Types at Once 143
8.4 Generating Pages with Mixed Content Types: Text and
Graphics 146
8.4.1 Ensuring That the Graph Is Current 153
Chapter 9 Using REQUEST INIT and REQUEST TERM to
Specify Set-up and Shut-down
Behavior 155
9.1 Introduction 155
9.2 Specifying the REQUEST INIT and REQUEST TERM
Programs 156
9.3 Using REQUEST INIT and REQUEST TERM 156
9.3.1 Defining Libraries and Files 157
9.3.2 Overriding or Supplying Parameter Values 159
9.3.3 Standard Header and Trailer Blocks 161
9.3.4 Terminating a Request 163
Contents vii
Chapter 10 How to Create and Use Sessions 165
10.1 Introduction 165
10.2 Creating a Session 166
10.3 Saving or Restoring All Macro Variables 171
10.4 Returning to a Previous State of a Session 175
10.5 Generating Friendlier Messages for Expired Sessions 179
10.6 Extending Sessions 182
10.7 Session INIT and TERM Programs 186
Part 4 Addressing Common Application
Requirements
Chapter 11 Tools and Techniques for Debugging 191
11.1 Introduction 191
11.2 Using the _debug Parameter 192
11.3 The PROC APPSRV LOG Statement 196
11.4 Conditionally Generating Debugging Output 197
11.5 Running Application Dispatcher Programs Using SAS Display
Manager 200
11.5.1 Special Handling for SCL Programs 201
11.6 Dedicating an Application Server for Debugging 202
Chapter 12 Tips for Safeguarding Security 205
12.1 Introduction 205
12.2 The Application Server Environment 206
12.2.1 Limiting Which Application Brokers Can Access an
Application Server 206
12.2.2 Hiding Passwords 208
12.2.3 Best Practices for a Secure Application Server
Environment 211
12.3 Controlling Access to Data and Reports 212
12.3.1 Customizing Menu Choices 219
12.3.2 Using AUTH=HOST 223
viii Contents
Chapter 13 Integrating Application Dispatcher
Applications with Other Applications,
Products, and Environments 225
13.1 Introduction 225
13.2 htmSQL 226
13.2.1 Integrating htmSQL with the Application Dispatcher 228
13.2.2 Integrating the Application Dispatcher with htmSQL 230
13.3 Single Sign-On Environments 235
13.4 External Session Facilities 236
Chapter 14 Maintaining an Applications
Environment 239
14.1 Introduction 239
14.2 Supporting Development, Test, and Production
Environments and Applications 239
14.2.1 Using a Developer’s Workstation 240
14.2.2 Distinct Services 240
14.2.3 Distinct Brokers 241
14.2.4 Customized INIT Program 242
14.3 Metadata Approaches to Minimize Code Changes 244
14.3.1 The getTextString Macro 249
Part 5 Selected Examples
Chapter 15 Generating Static Versions of Dynamic
Reports 253
15.1 Introduction 253
15.2 Sample Program 254
15.3 Ensuring That Generated Links Function Correctly 256
15.4 E-mailing Static Copies of Dynamic Reports 256
Chapter 16 Simulating a Pause and Resume Capability
for the Application Server 259
16.1 Introduction 259
16.2 Sample Implementation 260
16.2.1 The Metadata Control Table 262
16.2.2 The Toggle Program 263
16.2.3 Macro to Check Status 264
16.2.4 The HTML Templates 265
16.3 Doing More with the Sample 266
