my_notes.md

2) XML Overview

XML Types

XML Namespaces

We can define custom XML namespace, which needs to be unique name and with customized structure.

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3) Working with XML

Associat css style with XML

• We can associate css style for the XML elements like below.

  <?xml-stylesheet type="text/css" href="businesscard.css" ?>

• Nodes can be applied with custom css styling using the XML tag name directly like below.

  Name { color: blueviolet; }

Advanced Styling with CSS

• we can use custom attribute type and associate it with css to display custom styling.

  <phone type="mobile" primary="super-important">(415) 555-4567</phone>

  can be associated with css styling of

  phone[primary]::after { content: " (" attr(primary) ")"; }

  this will result to displayed in

  (65)123 - 456 (super important)

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4) Manipulating XML with DOM

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5) XML and XPath

XPath important concepts

Using XPath for selecting information

businesscard.xml

to select name

/BusinessCard/Name

text of name, using text() function

/BusinessCard/Name/text()

to select all phones

/BusinessCard/phone

to select specific phone number 1, using predicate

Take note that in xpath, referencing list index start from 1, not like 0 from other langagues

/Businesscard/phone[1]

last phone number, using last() function

/BusinessCard/phone[last()]

check specific words in text using contains() function

/BusinessCard/Name[contains(text(), 'Richard')]

get all phone numbers with the attributes "type"

/BusinessCard/phone[@type] (or) //phone[@type]

get all phone numbers with the attributes "type" of "work"

/BusinessCard/phone[@type='work'] (or) //phone[@type='work']

items.xml

we want to select photo of Coffee type

/items/item[type='Coffee']/photo

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6) XML and XSLT

What is XSLT?

• eXtensible Stylesheet Language Transformations
• Different than CSS - applies templates to XML data
• Written using XML syntax itself
• can transorm XML into almost anything
• can perform operations directly on the data.
• more at https://wwww.w3.org/TR/xslt

In below example, we are getting source element(SimpleTag) and replace with whatever we define in this XSLT template (in this case some html).

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7) XSLT Examples

If there is an issue of Cross-Origin Request Blocked on firefox testing, temporarily disable the setting during testing.

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8) Document Type Definition

• Provide way to contstrain XML document content
• Specify what kind of content can appear and where
• Can be included in XML file, or be external to document
• Relatively simple to write, but not powerful

DTD Syntax and Content

DTD Format

8.1) Declaring Elements in DTD

Example :

8.2) Declaring Attributes in DTD

Example: Below basically declare the rules that BusinessCard element needs to follow.

• There should be Name.

• followed by 1 or more phone.

• followed by optional email.

  <!ELEMENT BusinessCard (Name, phone+, email?)

  Example2: This means phone number is characters

• Additonally phone has attribute type with 4 values which are required.

  <!ELEMENT phone (#PCDATA)>

  <!ATTLIST phone type (mobile | work | fax | home) #REQUIRED>

Validation XML definition

• https://www.xmlvalidation.com/

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9) XML Schema

• Alternative way of specifying rules to DTDs
• Provide way to constrain XML document content
• Written in XML syntax
• Similar to DTDs, but more powerful and robust
  • Finar level of control than DTDs allow
  • Schema and XML files are always stored separately

XML Anatomy

9.1) Declaring Elements in Schema

9.1.1) Simple Schema Type

9.1.2) Complex Schema Type

9.2) Declaring Attributes in XML Schema

Testing using https://www.xmlvalidation.com/

• go to https://www.xmlvalidation.com/
• upload XML file
• tick Validate against external XML schema checkbox and click Validate.
• upload XSD file and validate it.