XML Engine Tutorial

Overview
• XML basics and Libname engine introduction
• Effectively reading XML files
• Introduction to the XML Mapper
•Writing XML files using SAS
• Common problems processing XML files



What is XML?
• XML is a set of rules used for defining &modeling structures
• XML is extensible & customizable
 Its greatest strength
 Its greatest weakness


XML Basics- Well Formed Files

Document has a single root element
• Elements nest properly
• No tag omission (close what you
open)
• Attributes must be quoted
• Special characters < > and & must
always be escaped
XML Basics- Well Formed Files
• XML is case sensitive



Anatomy of an XML file

<?xml version="1.0"?>
<workorder priority="high"datedue="09/30/2001">
<submitter>
<name first="Jennifer" last="Kyrnin" />
<email>html.guide@about.com</email>
<account number="11001100" />
Container or root XML Declaraton
Anatomy of an XML file
Copyr i g ht © 2012 , SAS Ins t i tut e Inc . Al l r ights reser ve d .
</submitter>
<project title="update aa051198.htm article">
<url>http://webdesign.com/aa051198.htm</url>
<description> new article</description>
</project>

</workorder>


Libname Engine Introduction

Release                                           Engine                                    Description               
SAS 8.1                                            XML                                     Export production   
SAS 8.2                                             XML                                  A bility to read added
                                                                                                           with hot fix            
SAS 9.1                                            XML                                                                        
SAS 9.2                                            XML|XML92                          Enhanced features
                                                                                                           Libname Engine   
                                                                                                            Introduction         
SAS 9.3|9.4                                      XML|XMLV2                         XMLV2 is an alias  
                                                                                                          of   XML92              






Libname Engine Introduction-Processing XML


• Provides the ability to read and write XML files
• Requires that XML files be well formed for reading

• Reads and writes generic XML files by default


• Wildcards can be used to read all files in a directory
• Allows hierarchical files to be read by dynamically
generating Map files
• Namespaces are supported beginning with SAS 9.3
• Provides the ability to use XMLMap files for export as well
Libname Engine Introduction-Extended Functionality
of the XMLV2 Engine as import.


Effectively Reading XML Files
<?xml version="1.0" ?>
<TABLE>
<STUDENTS>
<ID> 0755 </ID>
<NAME> Brad Martin </NAME>
<ADDRESS> 1611 Glengreen </ADDRESS>
<CITY> Huntsville </CITY>
<STATE> Texas </STATE>
</STUDENTS>
<STUDENTS>
<ID> 1522 </ID>
<NAME> Zac Harvell </NAME>
<ADDRESS> 11900 Glenda </ADDRESS>
<CITY> Houston </CITY>
<STATE> Texas </STATE>
</STUDENTS>
</TABLE>

Effectively Reading XML Files

Libname test xmlv2 'C:\students.xml';
proc print data=test.students;
run;
ID              NAME          ADDRESS            CITY          STATE
0755          Brad Martin  1611 Glengreen    Huntsville    Texas
1522          Zac Harvell   11900 Glenda       Houston        Texas

Effectively Reading XML Files- Attributes Require an XMLMap

<?xml version="1.0" ?>
<TABLE>
<STUDENTS Dept="Math">
<ID> 0755 </ID>
<NAME> Brad Martin </NAME>
<ADDRESS> 1611 Glengreen </ADDRESS>
<CITY> Huntsville </CITY>
<STATE> Texas </STATE>
</STUDENTS>
<STUDENTS Dept="CSC">
<ID> 1522 </ID>
<NAME> Zac Harvell </NAME>
<ADDRESS> 11900 Glenda </ADDRESS>
<CITY> Houston </CITY>
<STATE> Texas </STATE>
</STUDENTS>
</TABLE>

Effectively Reading XML Files-Required Structure

Problem.XML

__________________________________________

<xml version=“1.0” ?>            Declaration statement                           

__________________________________________

<Table>                                    SAS recognizes the first instance tag as

                                                  the root enclosing element, which is the

                                                   document container.

_________________________________________________

 <Students>                           Starting with the second-level instance                                                                                                    tag, SAS begins to scan for columns.

________________________________________________

<Student>                                 SAS expects to start reading data here and

                                                  because there is no data an error occurs

__________________________________________________

<ID> 0755 </ID>

<NAME> Brad Martin</NAME>

<ADDRESS> 1611 Glengreen

</ADDRESS>

<CITY> Huntsville </CITY>

<STATE> Texas </STATE>

</Student>

</Students>

</Table>

_______________________________________________