Xml -ror

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Revision as of 00:46, 2 February 2011 (view source) Sandoz-admin (Talk | contribs) ← Older edit		Latest revision as of 00:49, 2 February 2011 (view source) Sandoz-admin (Talk | contribs)
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Line 1:		Line 1:
	http://www.germane-software.com/software/rexml/docs/tutorial.html		http://www.germane-software.com/software/rexml/docs/tutorial.html
		+
		+	require 'rexml/document'
	1) Accessing Elements		1) Accessing Elements
Line 73:		Line 75:
	Using XPath		Using XPath
-	==========	+	-----------------------
-	# The invisibility cream is the first <item>	+	The invisibility cream is the first <item>
-	invisibility = XPath.first( doc, "//item" )	+	invisibility = XPath.first( doc, "//item" )
-	# Prints out all of the prices	+	# Prints out all of the prices
-	XPath.each( doc, "//price") { |element| puts element.text }	+	XPath.each( doc, "//price") { |element| puts element.text }
-	# Gets an array of all of the "name" elements in the document.	+	Gets an array of all of the "name" elements in the document.
-	names = XPath.match( doc, "//name" )	+	names = XPath.match( doc, "//name" )
	Using to_a()		Using to_a()
-	============	+	-----------------------
	all_elements = doc.elements.to_a		all_elements = doc.elements.to_a
	all_children = doc.to_a		all_children = doc.to_a
Line 89:		Line 91:
	Entity Replacement		Entity Replacement
-	===================	+	-----------------------
	doc = Document.new '<!DOCTYPE foo [		doc = Document.new '<!DOCTYPE foo [
	<!ENTITY ent "replace">		<!ENTITY ent "replace">
Line 97:		Line 99:
	Creating elements		Creating elements
-	=================	+	-----------------------
	el = someelement.add_element "myel"		el = someelement.add_element "myel"
-	# creates an element named "myel", adds it to "someelement", and returns it	+	creates an element named "myel", adds it to "someelement", and returns it
	el2 = el.add_element "another", {"id"=>"10"}		el2 = el.add_element "another", {"id"=>"10"}
-	# does the same, but also sets attribute "id" of el2 to "10"	+	does the same, but also sets attribute "id" of el2 to "10"
	el3 = Element.new "blah"		el3 = Element.new "blah"
	el1.elements << el3		el1.elements << el3
	el3.attributes["myid"] = "sean"		el3.attributes["myid"] = "sean"
-	# creates el3 "blah", adds it to el1, then sets attribute "myid" to "sean"	+	creates el3 "blah", adds it to el1, then sets attribute "myid" to "sean"
	Adding text		Adding text
-	=============	+	-----------------------
	el1 = Element.new "myelement"		el1 = Element.new "myelement"
	el1.text = "Hello world!"		el1.text = "Hello world!"
-	# -> <myelement>Hello world!</myelement>	+	-> <myelement>Hello world!</myelement>
	el1.add_text "Hello dolly"		el1.add_text "Hello dolly"
-	# -> <myelement>Hello world!Hello dolly</element>	+	-> <myelement>Hello world!Hello dolly</element>
	el1.add Text.new("Goodbye")		el1.add Text.new("Goodbye")
-	# -> <myelement>Hello world!Hello dollyGoodbye</element>	+	-> <myelement>Hello world!Hello dollyGoodbye</element>
	el1 << Text.new(" cruel world")		el1 << Text.new(" cruel world")
-	# -> <myelement>Hello world!Hello dollyGoodbye cruel world</element>	+	-> <myelement>Hello world!Hello dollyGoodbye cruel world</element>
	Encoded Output		Encoded Output
-	==============	+	-----------------------
	e = Element.new "<a/>"		e = Element.new "<a/>"
	e.text = "f\xfcr"  # ISO-8859-1 '??'		e.text = "f\xfcr"  # ISO-8859-1 '??'
Line 129:		Line 131:
	Inserts		Inserts
-	=============	+	-----------------------
	doc = Document.new "<a><one/><three/></a>"		doc = Document.new "<a><one/><three/></a>"
	doc.root[1,0] = Element.new "two"		doc.root[1,0] = Element.new "two"
-	# -> <a><one/><two/><three/></a>	+	-> <a><one/><two/><three/></a>
	three = doc.elements["a/three"]		three = doc.elements["a/three"]
	doc.root.insert_after three, Element.new "four"		doc.root.insert_after three, Element.new "four"
-	# -> <a><one/><two/><three/><four/></a>	+	-> <a><one/><two/><three/><four/></a>
-	# A convenience method allows you to insert before/after an XPath:	+	A convenience method allows you to insert before/after an XPath:
	doc.root.insert_after( "//one", Element.new("one-five") )		doc.root.insert_after( "//one", Element.new("one-five") )
-	# -> <a><one/><one-five/><two/><three/><four/></a>	+	-> <a><one/><one-five/><two/><three/><four/></a>
-	# Another convenience method allows you to insert after/before an element:	+	Another convenience method allows you to insert after/before an element:
	four = doc.elements["//four"]		four = doc.elements["//four"]
	four.previous_sibling = Element.new("three-five")		four.previous_sibling = Element.new("three-five")
-	# -> <a><one/><one-five/><two/><three/><three-five/><four/></a>	+	-> <a><one/><one-five/><two/><three/><three-five/><four/></a>
	Automatic raw text handling		Automatic raw text handling
-	===========================	+	-----------------------
	doc = REXML::Document.new( source, { :raw => %w{ tag1 tag2 tag3 } }		doc = REXML::Document.new( source, { :raw => %w{ tag1 tag2 tag3 } }
	Raw documents		Raw documents
-	================	+	-----------------------
	doc = REXML::Document.new( source, { :raw => :all })		doc = REXML::Document.new( source, { :raw => :all })
	Stream parsing		Stream parsing
-	================	+	-----------------------
	list = MyListener.new		list = MyListener.new
	source = File.new "mydoc.xml"		source = File.new "mydoc.xml"
	REXML::Document.parse_stream(source, list)		REXML::Document.parse_stream(source, list)

---

Latest revision as of 00:49, 2 February 2011

http://www.germane-software.com/software/rexml/docs/tutorial.html

require 'rexml/document'

1) Accessing Elements

---

doc = Document.new File.new("mydoc.xml")

doc.elements.each("inventory/section") { |element| puts element.attributes["name"] }

-> health

-> food

doc.elements.each("*/section/item") { |element| puts element.attributes["upc"] }

-> 123456789

-> 445322344

-> 485672034

-> 132957764

root = doc.root

puts root.attributes["title"]

-> OmniCorp Store #45x10^3

puts root.elements["section/item[@stock='44']"].attributes["upc"]

-> 132957764

puts root.elements["section"].attributes["name"]

-> health (returns the first encountered matching element) 

puts root.elements[1].attributes["name"]

-> health (returns the FIRST child element) 

root.detect {|node| node.kind_of? Element and node.attributes["name"] == "food" }

2) The source document

---

<inventory title="OmniCorp Store #45x10^3">

 <section name="health">
   <item upc="123456789" stock="12">
     <name>Invisibility Cream</name>
     <price>14.50</price>
     <description>Makes you invisible</description>
   </item>
   <item upc="445322344" stock="18">
     <name>Levitation Salve</name>
     <price>23.99</price>
     <description>Levitate yourself for up to 3 hours per application</description>
   </item>
 </section>
 <section name="food">
   <item upc="485672034" stock="653">
     <name>Blork and Freen Instameal</name>
     <price>4.95</price>
     <description>A tasty meal in a tablet; just add water</description>
   </item>
   <item upc="132957764" stock="44">
     <name>Grob winglets</name>
     <price>3.56</price>
     <description>Tender winglets of Grob. Just add water</description>
   </item>
 </section>

</inventory>

Using XPath

---

The invisibility cream is the first <item>
invisibility = XPath.first( doc, "//item" ) 
# Prints out all of the prices
XPath.each( doc, "//price") { |element| puts element.text }
Gets an array of all of the "name" elements in the document.
names = XPath.match( doc, "//name" ) 

Using to_a()

---

all_elements = doc.elements.to_a all_children = doc.to_a all_upc_strings = doc.elements.to_a( "//item/attribute::upc" ) all_name_elements = doc.elements.to_a( "//name" )

Entity Replacement

---

doc = Document.new '<!DOCTYPE foo [ <!ENTITY ent "replace"> ]><a>&ent;</a>' doc.root.text #-> "replace"

Creating elements

---

el = someelement.add_element "myel"

creates an element named "myel", adds it to "someelement", and returns it 

el2 = el.add_element "another", {"id"=>"10"}

does the same, but also sets attribute "id" of el2 to "10" 

el3 = Element.new "blah" el1.elements << el3 el3.attributes["myid"] = "sean"

creates el3 "blah", adds it to el1, then sets attribute "myid" to "sean"

Adding text

---

el1 = Element.new "myelement" el1.text = "Hello world!"

-> <myelement>Hello world!</myelement> 

el1.add_text "Hello dolly"

 -> <myelement>Hello world!Hello dolly</element> 

el1.add Text.new("Goodbye")

-> <myelement>Hello world!Hello dollyGoodbye</element> 

el1 << Text.new(" cruel world")

-> <myelement>Hello world!Hello dollyGoodbye cruel world</element>

Encoded Output

---

e = Element.new "<a/>" e.text = "f\xfcr" # ISO-8859-1 '??' o = e.write( Output.new( o, "ISO-8859-1" ) )

Inserts

---

doc = Document.new "<a><one/><three/></a>" doc.root[1,0] = Element.new "two"

-> <a><one/><two/><three/></a> 

three = doc.elements["a/three"] doc.root.insert_after three, Element.new "four"

 -> <a><one/><two/><three/><four/></a> 
 A convenience method allows you to insert before/after an XPath: 

doc.root.insert_after( "//one", Element.new("one-five") )

 -> <a><one/><one-five/><two/><three/><four/></a> 
 Another convenience method allows you to insert after/before an element: 

four = doc.elements["//four"] four.previous_sibling = Element.new("three-five")

 -> <a><one/><one-five/><two/><three/><three-five/><four/></a>

Automatic raw text handling

---

doc = REXML::Document.new( source, { :raw => %w{ tag1 tag2 tag3 } }

Raw documents

---

doc = REXML::Document.new( source, { :raw => :all })

Stream parsing

---

list = MyListener.new source = File.new "mydoc.xml" REXML::Document.parse_stream(source, list)