Skip to main content

Building the Foundation of the PO System: XML and XSD Explained with Examples

Understanding XML and XSD is vital for comprehending the backbone of the Process Orchestration (PO) system. Let's take a closer look at these concepts with practical examples and technical details.

XML: The Universal Language for Data

XML enables the sharing and structuring of data across various platforms.

1. What is XML?

  • Tags and Elements: Tags define elements and are like containers for data.
    • Example: <name>John Doe</name> Here, "name" is the tag, and "John Doe" is the element.
  • Attributes: They provide more information about the elements.
    • Example: <employee id="123">John Doe</employee> Here, "id" is an attribute.

2. XML vs. HTML:

  • XML Describes Data: It focuses on what the data is.
  • HTML Displays Data: It concentrates on how data looks.
    • Example: XML might describe a book's title, while HTML shows how the title appears on a webpage.

3. XML Syntax and Namespace:

  • Syntax: It follows specific rules, such as closing tags.
    • Example: <name>John Doe</name> is correct, whereas <name>John Doe is incorrect.
  • Namespace: Prevents conflicts between similar elements.
    • Example: Using different namespaces for customer names and employee names in the same document.

XSD: The Rulebook for XML

XSD outlines the rules that XML documents must follow.

1. What is XSD?

  • Example: Imagine a library catalog system. XSD dictates that each book entry must have a title, author, and ISBN number.
<xs:element name="title" type="xs:string"/> <xs:element name="author" type="xs:string"/> <xs:element name="ISBN" type="xs:integer"/>

2. Relationship Between XSD and XML:

  • Defining Structure: Ensures XML adheres to specific rules.
  • Example: An XSD might require a customer's phone number in XML to be a numerical value. It prevents entering text or special characters.

3. Comparison Between XSD and DSD:

  • XSD: More strict, follows specific rules.
  • DSD: Allows for variations.
  • Example: XSD is like a legal contract with specific terms, whereas DSD is like a handshake agreement.

Real-World Business Scenario: Managing a Global Retail Chain

Imagine a global retail chain with stores across various countries.

  1. Using XML: Each store might send daily sales data in XML format to the headquarters.
    • Example: <sales><store id="NYC"><total>1000</total></store></sales>
  2. Using XSD: To ensure that the XML data from each store follows the same format, an XSD is applied. It's like having a standardized form that all store managers must fill out.
    • Example: The XSD would specify that the store ID must be a text string, and the total sales must be a numerical value.

XML and XSD are more than mere technical terms; they are essential building blocks in creating a coherent, efficient data transfer system. By setting rules (XSD) and defining the structure (XML), they lay the foundation for smooth business operations across different platforms.

These concepts, with their underlying examples and technical details, reflect the synergy and precision necessary in today's fast-paced business environment. Think about how this alignment between data description (XML) and data validation (XSD) can drive your organization's success.

XPath, or XML Path Language, is an essential component in working with XML. It allows you to navigate through elements and attributes in an XML document, making it a vital tool for querying and extracting specific information. Here's an overview along with an example.

XPath: Navigating Through XML

XPath uses a path expression to select nodes or node-sets in an XML document. These path expressions look somewhat similar to the expressions used in file systems, where you define a path to access a file or folder.

Syntax and Usage:

XPath expressions can have various components to select different parts of an XML document, such as elements, attributes, text, etc.

  • "/" selects from the root node.
  • "//" selects nodes from the current node matching the selection, regardless of where they are in the document.
  • "@" is used to select attributes.

Example: XML Document

Let's take an example XML document representing a bookstore:

<bookstore> <book category="fiction"> <title lang="en">The Great Gatsby</title> <author>F. Scott Fitzgerald</author> <price>10.99</price> </book> <book category="non-fiction"> <title lang="es">Don Quixote</title> <author>Miguel de Cervantes</author> <price>15.99</price> </book> </bookstore>

XPath Expressions and Their Results:

  • /bookstore/book[1] selects the first "book" element under the "bookstore" root.
  • //book[@category='fiction']/title selects the "title" of all "book" elements with the attribute "category" equal to "fiction."
  • //title[@lang='en']/text() retrieves the text content of the "title" elements where the attribute "lang" equals "en," resulting in "The Great Gatsby."

Using XPath: Practical Examples

Consider the same bookstore XML document. You want to find specific books or details based on various criteria.

1. Finding a Specific Book by Category and Language:

  • XPath Expression: //book[@category='fiction']/title[@lang='en']
  • Result: Selects the title of the fiction book that's in English.
  • Usage in Code (e.g., Python with lxml library):
    from lxml import etree tree = etree.parse('bookstore.xml') result = tree.xpath("//book[@category='fiction']/title[@lang='en']") for title in result: print(title.text) # Output: The Great Gatsby

2. Finding All Prices in the Non-fiction Category:

  • XPath Expression: //book[@category='non-fiction']/price
  • Result: Selects all price elements for non-fiction books.
  • Adding More (e.g., selecting price > 10): //book[@category='non-fiction']/price[.>10]
  • Usage in Code:
    prices = tree.xpath("//book[@category='non-fiction']/price[.>10]") for price in prices: print(price.text) # Output: 15.99

3. Adding More Complexity: Selecting Based on Multiple Criteria:

  • XPath Expression: //book[author='Miguel de Cervantes' and @category='non-fiction']/title
  • Result: Selects the title of non-fiction books authored by Miguel de Cervantes.
  • Usage in Code:
    titles = tree.xpath("//book[author='Miguel de Cervantes' and @category='non-fiction']/title") for title in titles: print(title.text) # Output: Don Quixote


Post a Comment

You might find these interesting

How to properly Start/Stop SAP system through command line ?

Starting/stopping an SAP system is not a critical task, but the method that most of us follow to achieve this is sometimes wrong. A common mistake that most of the SAP admins do is, making use of the 'startsap' and 'stopsap' commands for starting/stopping the system.  These commands got deprecated in 2015 because the scripts were not being maintained anymore and SAP recommends not to use them as many people have faced errors while executing those scripts. For more info and the bugs in scripts, you can check the sap note 809477.  These scripts are not available in kernel version 7.73 and later. So if these are not the correct commands, then how to start/stop the sap system?  In this post, we will see how to do it in the correct way. SAP SYSTEM VS INSTANCE In SAP, an instance is a group of resources such as memory, work processes and so on, usually in support of a single application server or database server with

sapstartsrv is not started or sapcontrol is not working

 What is sapstartsrv ? The SAP start service runs on every computer where an instance of an SAP system is started. It is implemented as a service on Windows, and as a daemon on UNIX. The process is called  sapstartsrv.exe   on Windows, and   sapstartsrv   on UNIX platforms. The SAP start service provides the following functions for monitoring SAP systems, instances, and processes. Starting and stopping Monitoring the runtime state Reading logs, traces, and configuration files Technical information, such as network ports, active sessions, thread lists, etc. These services are provided on SAPControl SOAP Web Service, and used by SAP monitoring tools (SAP Management Console,  SAP NetWeaver  Administrator, etc.). For more understanding use this link : How to check if it is working or not ? In case of linux , you can simply ps -ef | grep sapstartsrv In case of windows, you need

HANA System Replication - Prerequisites & Setup

Hey Folks! Welcome back to Hana high availability blog series. In our last blog we checked out operation & replication modes in hana system replication. If you haven't gone though that blog, you can checkout  this link In this blog we will be talking about the prerequisites of hana replication and it's setup. So let's get started. When we plan to setup hana system replication, we need to make sure that all prerequisite steps have been followed. Let's have a look at these prerequisites. HANA System Replication Prerequisites: Primary & secondary systems should be up & running HDB version of secondary should be greater than or equal to Primary database sever But, for Active/Active(read enabled config), HDB version should be same on both sites. System configuration/ini files should be identical on both sides Replication happe

ST03N : The chapter for all BASIS Admins

This blog is targeted to BASIS ADMINS Transaction for workload analysis statistical data changed over time are monitored using transaction code ST03 , now ST03N (from SAP R/3 4.6C) . With SAP Web AS 6.4 the transaction ST03 is available again. From time to time ST03 and ST03N has seen many changes but later in SAP NW7.0 ST03N has reworked in detail specially processing time is now shown in separate column. Main Use of ST03N  is to get detailed information on performance of any ABAP based SAP system. Workload monitor analyzes the statistical data originally collected by kernel. You can compare or analyze the performance of a single application server or multiple application server. Using this you start checking from the entire system and finding your way to that one application server and narrowing down to exact issue. By Default :- You see data of current day as default view , you can change the default view. Source of the image : Let's discuss the WORKLOAD MONITOR By D

How to resolve Common Error : Standard Template "sap_sm.xls" missing

Hey everyone, putting forward a common error we usually face when we have “ Excel inplace” functionality enabled in our SAP system. This error occurs when validity of the signature of SAP standard templates expired or were incorrectly delivered via support packages. We can reproduce the error by doing as below.. Click on “spreadsheet” icon after any SAP ALV grid view of data is on screen to make this data to export into excel directly from SAP.

HANA hdbuserstore

The hdbuserstore (hana secure user store) is a tool which comes as an executable with the SAP Hana Client package. This secure user store allows you to store SAP HANA connection information, including user passwords, securely on clients. With the help of secure store, the client applications can connect to SAP HANA without the user having to enter host name or logon credentials. You can also use the secure store to configure failover support for application servers in a 3-tier scenario (for example, SAP Business Warehouse) by storing a list of all the hosts that the application server can connect to. To access the system using secure store, there are two connect options: (1)key and (2)virtualHostName. key is the hdbuserstore key that you use to connect to SAP HANA, while virtualHostName specifies the virtual host name. This option allows you to change where the hdbuserstore searches for the data and key files. Note

SUM Tool : An Introduction

Let’s Discuss about the famous tool, that is asked in almost all the Basis and HANA interview and it is very easy to understand but a bit tricky. Tighten your seatbelts and Let’s understand in one go. SAP Technical Upgrade is a periodic project that is implemented across companies to upgrade their SAP system to the latest released version. Most of the upgrade activities are done by the technical team and the role of functional consultants is limited and mostly confined to regression testing What are the maintenance that are performed by help of SUM ? Release upgrade (major release change) System update (EHP installation) applying Support Packages (SPs) / Support Package Stacks applying Java patches correction of installed software information combine update and migration to SAP HANA (DMO: Database Migration Option) System Conversion from SAP ERP to SAP S/4HANA   First thing first , never confuse in these two things : Upgrade and Update. Updating SAP products is for applying support pac

SAP HANA System Replication - Operation Mode & Replication Mode

Hey Folks! Welcome back to Hana high availability blog series. In our last blog we checked out what is hana system replication and how it basically works. If you haven't gone through that blog, you can checkout link In this blog we will be talking about the replication modes and operation modes in hana system replication. So let's get started. When we setup the replication and register the secondary site, we need to decide the operation mode & replication mode we want to choose for replication. For now we won't focus on setting up replication as we'll cover it in our next blogs.  Operation Modes in Hana System Replication: There are three operation modes available in system replication: delta_datashipping, logreplay and logreplay_readaccess. Default operation mode is logreplay. 1. Delta_datashipping: In this operation mode initially one full data shipping is done as part of replication setup and then a delta data shipping takes place occasionally in addition to cont

Work Process and Memory Management in SAP

Let’s talk about the entire concepts that are related to memory when we talk about SAP Application. Starting with few basic terminologies, Local Memory :  Local process memory, the operating system keeps the two allocation steps transparent. The operating system does the other tasks, such as reserving physical memory, loading and unloading virtual memory into and out of the main memory. Shared Memory :  If several processes are to access the same memory area, the two allocation steps are not transparent. One object is created that represents the physical memory and can be used by various processes. The processes can map the object fully or partially into the address space. The way this is done varies from platform to platform. Memory mapped files, unnamed mapped files, and shared memory are used.  Extended Memory : SAP extended memory is the core of the SAP memory management system. Each SAP work process has a part reserved in its virtual address space for extended memory. You can set

Complete Guide : XPI Inspector Tool

Content of this blog :           What is an XPI Inspector Tool ? Why XPI Tool is used ? XPI standard URL How to check XPI Tool version ? How to Install/Update XPI version using TELNET How to Use XPI Tool ? References – SAP Notes What is XPI Inspector tool ?          -    XPI Inspector is a diagnostics web application developed by SAP that collects logs and debug traces from various PI components in a very simple way and is useful for SAP PI consultants, developers, and administrators to get more insights on an issue. Why XPI is used  – 1.  Used to collect traces and logs from Messaging system or XI module. 2. Used to collect the related information to solving the issues or improving the PI or PO systems’ performance. 3. Using XPI Inspector application you will be able to collect a lot of information about your system that will help you to learn about problems in the past, to analyze new and detect such at an early stage. 4. Performs certain number of configuration checks, such as SSL c