Book Image

QlikView for Developers Cookbook

By : Stephen Redmond
Book Image

QlikView for Developers Cookbook

By: Stephen Redmond

Overview of this book

QlikView has been around since 1993, but has only really taken off in recent years as a leader in the in-memory BI space and, more recently, in the data discovery area. QlikView features the ability to consolidate relevant data from multiple sources into a single application, as well as an associative data model to allow you to explore the data to a way your brain works, state-of-the-art visualizations, dashboard, analysis and reports, and mobile data access. QlikView for Developers Cookbook builds on your initial training and experiences with QlikView to help you become a better developer. This book features plenty of hands-on examples of many challenging functions. Assuming a basic understanding of QlikView development, this book provides a range of step-by-step exercises to teach you different subjects to help build your QlikView developer expertise. From advanced charting and layout to set analysis; from advanced aggregations through to scripting, performance, and security, this book will cover all the areas that you need to know about. The recipes in this book will give you a lot of the information that you need to become an excellent QlikView developer.
Table of Contents (19 chapters)
QlikView for Developers Cookbook
Credits
Foreword
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Using parameters in Dollar Sign Expansion


In the script, we generally use Dollar Sign Expansion to access variable values. However, we can also use them to create macro functions in the script. This is very useful if you need to repeat a function several times.

In this recipe, we are going to extend the mapping function by being able to pass two parameters, and return a different result depending upon which one maps successfully.

Getting ready

Load the following script:

Map1:
Mapping Load * Inline [
  map_from, map_to
  A, 1
  B, 2
  C, 3
];

Map2:
Mapping Load * Inline [
  map_from, map_to
  A, 0.1
  B, 0.2
  C, 0.3
];

SET myMacro=Alt(ApplyMap('Map1', $1, Null()), ApplyMap('Map2', $2, Null()), 0);
Load 
  *
Inline [
  Parm1, Parm2
  A, A
  A, B
  B, A
  C, A
  D, A
  D, B
];

How to do it...

These steps show how to use parameters in a dollar sign expansion:

  1. Add a table box and add Parm1 and Parm2.

  2. Edit the script. Replace the * with the following:

    *, $(myMacro(Parm1, Parm2)) As Res
  3. Reload and add...