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Enterprise IT [Πληροφοριακές Τεχνολογίες της Επιχείρησης] Lecture 4 & 5: XML Overview Univ. of the Aegean Financial and Management Engineering Dpt. Petros KAVASSALIS. What you will learn in this course.
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Enterprise IT[Πληροφοριακές Τεχνολογίες της Επιχείρησης]Lecture 4 & 5: XML OverviewUniv. of the Aegean Financial and Management Engineering Dpt Petros KAVASSALIS
What you will learn in this course • A set offundamentalconceptsfor understanding basic Enterprise Information Technologies • Enterprise Software Applications • Enterprise Architecture Integration (EAI) • Best practices and techniques for building and migrating to a service-oriented enterprise • Strategies for integrating applications using standard technologies • XML • Web Services • Familiarization with concepts such as: • Interoperability • e-business • e-government 2.0
Communication tools • e-mail: pkavassalis@atlantis-group.gr • Course web site: see FME web site
Students evaluation • Class Participation (20%) + • Assignments (20%) + • Final Exam (650%)
XML in a nutshell • XML: Extensible Markup Language • XML Working Group at W3C (please visit!) • Used for the definition of methods of storing, processing and managing information (texts) in electronic form • Device independent • System independent • Used to represent business transactions within and outside the enterprise and mediate communication between systems that support transactions • Example: purchase orders, invoices, shipping, bills of lading, warehousing information delivery etc • Used to standardize the process by which enterprise applications exchange message in the context of a transaction (within the enterprise or between trading partners)
Markup etc. • Markup • Describe annotations or special marks (codes) inserted into electronic texts to govern text formatting, processing, printing etc. • Make explicit the representation of text • Markup language • A set of conventions put together for encoding texts • What markup? • What is required? • What does it mean? • How can it be distinguished from text? • Meta-language • Provides a way of formally describing a language, i.e. a markup language • XML: no predetermined tags • XML: Descriptive markup (the mark-up annotations simply categorize parts of the document)
Re-usability • A language for creating other languages! • One uses XML to design his (her) own custom markup language (XMP application) • The, he(she) uses this custom language to format documents • A tag identifies (characterizes) data, data in that way become available for other tasks • Labeled information that can be re-used • Sister technology: XML Schemas • Defines the custom markup language one creates with XML • Specifies tags to use in a document • Tags and attributes these tags can contain
XML: Elements, Attributes and Values • http://www.w3schools.com/xml/default.asp • <?xml version="1.0"?> • <note> • <to>Tove</to> • <from>Jani</from> • <heading>Reminder</heading> • <body>Don't forget me this weekend!</body> • </note> • http://www.w3schools.com/xml/xml_tree.asp
Note: [Reference for the following examples] • http://elizabethcastro.com/xml/examples/index.html#ch1
XML: Declaring the version, root element and other rules <?xml version="1.0" ?> <endangered_species /> • Closing tags are required • Case matters • Values must enclosed in quotations
XML: Nesting elements <inner> <?xml version="1.0" ?> <endangered_species> <animal> <name>Tiger</name> <threat>poachers</threat> <weight>500 pounds</weight> </animal> </endangered_species> • Important: The elements in an XML document form a document tree. The tree starts at the root and branches to the lowest level of the tree. An element nested with another is referred to as “child element” (or, inversely, “parent element”) • <root> <child> <subchild>.....</subchild> </child></root> animal: 3 child elements
XML: Attributes <?xml version="1.0" ?> <endangered_species> <animal> <name language="English">Tiger</name> <name language="Latin">pantheratigris</name> <threat>poachers</threat> <weight>500 pounds</weight> </animal> </endangered_species>
XML: Empty Elements <?xml version="1.0" ?> <endangered_species> <animal> <name language="English">Tiger</name> <name language="Latin">pantheratigris</name> <threat>poachers</threat> <weight>500 pounds</weight> <source sectionid="120" newspaperid="21" /> <picture filename="tiger.jpg" x="200" y="197" /> </animal> </endangered_species>
XML: Writing comments <?xml version="1.0" ?> <endangered_species> <animal> <name language="English">Tiger</name> <name language="Latin">pantheratigris</name> <threat>poachers</threat> <weight>500 pounds</weight> <!-- the source tag references the corresponding article on the World Wildlife Fund web site --> <source sectionid="120" newspaperid="21" /> <picture filename="tiger.jpg" x="200" y="197" /> </animal> </endangered_species>
XML: Special Symbols(&, <, >, ", &apos) <?xml version="1.0" ?> <endangered_species> <animal> <name language="English">Tiger</name> <name language="Latin">pantheratigris</name> <threat>poachers</threat> <weight><500 pounds</weight> <!-- the source tag references the corresponding article on the World Wildlife Fund web site --> <source sectionid="120" newspaperid="21" /> <picture filename="tiger.jpg" x="200" y="197" /> </animal> </endangered_species>
XML: Displaying elements as text <?xml version="1.0" ?> <xml_book> <tags> <appearance> <![CDATA[ <endangered_species> <animal> <name language="English">Tiger</name> <name language="Latin">pantheratigris</name> <threat>poachers</threat> <weight>500 pounds</weight> <!--the source tag references the corresponding article on the World Wildlife Fund web site--> <source sectionid="120" newspaperid="21"></source> <picture filename="tiger.jpg" x="200" y="197"/> </animal> </endangered_species> ]]> </appearance> </tags> </xml_book>
Check point: Understand an XML document • Please visit: Debugging an XML document • http://faculty.matcmadison.edu/schmidt/xml/exer1.html
Homework • Take a catalogue from a furniture shop • Create an XML document
Check point: Create an XML Document[Reference: Allen Schmidt Class Support Home Page] • Items = {Item} <--This means that there are multiple Item entries within Items Item contains • Item Number • Description • Selling Price • Cost • Quantity On Hand • Date Last Received • Quantity Sold; Year-To-Date (current) / *modification • Warehouse Section • Warehouse Shelve {Supplier} <-- This means that there are several suppliers for each item • Instructions • First structure the information • Then, create the document • At the end, validate it!