From 6c3fb00239fc0a6bb518a5b086827140403bbb1a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Guilherme=20Farias=20Duda?= <jgfd@cin.ufpe.br>
Date: Fri, 14 Mar 2014 14:37:48 -0200
Subject: [PATCH 1/2] Create xml.html.markdown

---
 xml.html.markdown | 7 +++++++
 1 file changed, 7 insertions(+)
 create mode 100644 xml.html.markdown

diff --git a/xml.html.markdown b/xml.html.markdown
new file mode 100644
index 00000000..4063afdc
--- /dev/null
+++ b/xml.html.markdown
@@ -0,0 +1,7 @@
+---
+language: xml
+filename: learnxml.xml
+contributors:
+  - ["João Farias", "https://github.com/JoaoGFarias"]
+---
+

From 91bab3c90cd8b8b16521b7359977edcd90bc6bdc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Guilherme=20Farias=20Duda?= <jgfd@cin.ufpe.br>
Date: Fri, 14 Mar 2014 15:53:38 -0200
Subject: [PATCH 2/2] XML - Syntax and Document Definition using DTD

The only problem was highlighting the DTD code without breaking the XML code block.
---
 xml.html.markdown | 124 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 124 insertions(+)

diff --git a/xml.html.markdown b/xml.html.markdown
index 4063afdc..349d4763 100644
--- a/xml.html.markdown
+++ b/xml.html.markdown
@@ -5,3 +5,127 @@ contributors:
   - ["João Farias", "https://github.com/JoaoGFarias"]
 ---
 
+XML is a markup language designed to store and transport data.
+
+Unlike HTML, XML does not specifies how to display or to format data, just carry it.
+
+* XML Syntax
+
+```XML
+<!-- Comments in XML are like this -->
+
+<?xml version="1.0" encoding="UTF-8"?>
+<bookstore>
+  <book category="COOKING">
+    <title lang="en">Everyday Italian</title>
+    <author>Giada De Laurentiis</author>
+    <year>2005</year>
+    <price>30.00</price>
+  </book>
+  <book category="CHILDREN">
+    <title lang="en">Harry Potter</title>
+    <author>J K. Rowling</author>
+    <year>2005</year>
+    <price>29.99</price>
+  </book>
+  <book category="WEB">
+    <title lang="en">Learning XML</title>
+    <author>Erik T. Ray</author>
+    <year>2003</year>
+    <price>39.95</price>
+  </book>
+</bookstore>
+
+<!-- Above is a typical XML file.
+  It starts with a declaration, informing some metadata (optional)
+  
+  XML uses a tree structure. Above, the root node is 'bookstore', which has
+  three child nodes, all 'books'. Those nodes has more child nodes, and so on... 
+  
+  Nodes are created using open/close tags, and childs are just nodes between
+  the open and close tags.-->
+
+
+<!-- XML carries two kind of data:
+  1 - Attributes -> That's metadata about a node.
+      Usually, the XML parser uses this information to store the data properly.
+      It is characterized by appearing in parenthesis within the opening tag
+  2 - Elements -> That's pure data.
+      That's what the parser will retrive from the XML file.
+      Elements appear between the open and close tags, without paranthesis. -->
+      
+  
+<!-- Below, an element with two attributes -->
+<file type="gif" id="4293">computer.gif</file>
+
+
+```
+
+* Well-Formated Document x Validation
+
+A XML document is well-formated if it is syntactically correct.
+However, is possible to inject more constraints in the document,
+using document definitions, such as DTD and  XML Schema.
+
+A XML document which follows a document definition is called valid, 
+regarding that document. 
+
+With this tool, you can check the XML data outside the application logic.
+
+```XML
+
+<!-- Below, you can see an simplified version of bookstore document, 
+  with the addition of DTD definition.-->
+
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE note SYSTEM "Bookstore.dtd">
+<bookstore>
+  <book category="COOKING">
+    <title >Everyday Italian</title>
+    <price>30.00</price>
+  </book>
+</bookstore>
+
+<!-- This DTD could be something like:-->
+
+<!DOCTYPE note
+[
+<!ELEMENT bookstore (book+)>
+<!ELEMENT book (title,price)>
+<!ATTLIST book category CDATA "Literature">
+<!ELEMENT title (#PCDATA)>
+<!ELEMENT price (#PCDATA)>
+]>
+
+
+<!-- The DTD starts with a declaration.
+  Following, the root node is declared, requiring 1 or more child nodes 'book'.
+  Eeach 'book' should contain exactly one 'title' and 'price' and an attribute
+  called 'category', with "Literature" as its default value.
+  The 'title' and 'price' nodes contain a parsed character data.-->
+
+<!-- The DTD could be declared inside the XML file itself.-->
+
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!DOCTYPE note
+[
+<!ELEMENT bookstore (book+)>
+<!ELEMENT book (title,price)>
+<!ATTLIST book category CDATA "Literature">
+<!ELEMENT title (#PCDATA)>
+<!ELEMENT price (#PCDATA)>
+]>
+
+<bookstore>
+  <book category="COOKING">
+    <title >Everyday Italian</title>
+    <price>30.00</price>
+  </book>
+</bookstore>
+
+
+```
+      
+      
+