Xml -ror

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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

 <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)

Xml -ror

From Sandoz

Latest revision as of 00:49, 2 February 2011

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@@ Line 1: / Line 1: @@
 http://www.germane-software.com/software/rexml/docs/tutorial.html
-Accessing Elements
+require 'rexml/document'
-==================
+) Accessing Elements
+-----------------------
 doc = Document.new File.new("mydoc.xml")
 doc.elements.each("inventory/section") { |element| puts element.attributes["name"] }
-# -> health
-# -> food
+ -> health
+ -> food
 doc.elements.each("*/section/item") { |element| puts element.attributes["upc"] }
-# -> 123456789
-# -> 445322344
+ -> 123456789
-# -> 485672034
-# -> 132957764
+ -> 445322344
+ -> 485672034
+ -> 132957764
 root = doc.root
 puts root.attributes["title"]
-# -> OmniCorp Store #45x10^3
+ -> OmniCorp Store #45x10^3
 puts root.elements["section/item[@stock='44']"].attributes["upc"]
-# -> 132957764
+ -> 132957764
 puts root.elements["section"].attributes["name"]
-# -> health (returns the first encountered matching element)
+ -> health (returns the first encountered matching element)
 puts root.elements[1].attributes["name"]
-# -> health (returns the FIRST child element)
+ -> health (returns the FIRST child element)
 root.detect {|node| node.kind_of? Element and node.attributes["name"] == "food" }
-The source document
+) The source document
-==================
+---------------------
 <inventory title="OmniCorp Store #45x10^3">
    <section name="health">
@@ Line 53: / Line 75: @@
 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()
-============
+-----------------------
 all_elements = doc.elements.to_a
 all_children = doc.to_a
@@ Line 69: / Line 91: @@
 Entity Replacement
-===================
+-----------------------
 doc = Document.new '<!DOCTYPE foo [
 <!ENTITY ent "replace">
@@ Line 77: / Line 99: @@
 Creating elements
-=================
+-----------------------
 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"}
-# 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"
 el1.elements << el3
 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
-=============
+-----------------------
 el1 = Element.new "myelement"
 el1.text = "Hello world!"
-# -> <myelement>Hello world!</myelement>
+ -> <myelement>Hello world!</myelement>
 el1.add_text "Hello dolly"
-# -> <myelement>Hello world!Hello dolly</element>
+  -> <myelement>Hello world!Hello dolly</element>
 el1.add Text.new("Goodbye")
-# -> <myelement>Hello world!Hello dollyGoodbye</element>
+ -> <myelement>Hello world!Hello dollyGoodbye</element>
 el1 << Text.new(" cruel world")
-# -> <myelement>Hello world!Hello dollyGoodbye cruel world</element>
+ -> <myelement>Hello world!Hello dollyGoodbye cruel world</element>
 Encoded Output
-==============
+-----------------------
 e = Element.new "<a/>"
 e.text = "f\xfcr"   # ISO-8859-1 '??'
@@ Line 109: / Line 131: @@
 Inserts
-=============
+-----------------------
 doc = Document.new "<a><one/><three/></a>"
 doc.root[1,0] = Element.new "two"
-# -> <a><one/><two/><three/></a>
+ -> <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><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") )
-# -> <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.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
-===========================
+-----------------------
 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)