Class: Hpricot::Elements

Inherits:
Array show all
Defined in:
lib/ext/hpricot/inspect.rb,
lib/ext/hpricot/elements.rb

Overview

Once you've matched a list of elements, you will often need to handle them as a group. Or you may want to perform the same action on each of them. Hpricot::Elements is an extension of Ruby's array class, with some methods added for altering elements contained in the array.

If you need to create an element array from regular elements:

Hpricot::Elements[ele1, ele2, ele3]

Assuming that ele1, ele2 and ele3 contain element objects (Hpricot::Elem, Hpricot::Doc, etc.)

Continuing Searches

Usually the Hpricot::Elements you're working on comes from a search you've done. Well, you can continue searching the list by using the same at and search methods you can use on plain elements.

elements = doc.search("/div/p")
elements = elements.search("/a[@href='http://hoodwink.d/']")
elements = elements.at("img")

Altering Elements

When you're altering elements in the list, your changes will be reflected in the document you started searching from.

doc = Hpricot("That's my <b>spoon</b>, Tyler.")
doc.at("b").swap("<i>fork</i>")
doc.to_html
  #=> "That's my <i>fork</i>, Tyler."

Getting More Detailed

If you can't find a method here that does what you need, you may need to loop through the elements and find a method in Hpricot::Container::Trav which can do what you need.

For example, you may want to search for all the H3 header tags in a document and grab all the tags underneath the header, but not inside the header. A good method for this is next_sibling:

doc.search("h3").each do |h3|
  while ele = h3.next_sibling
    ary << ele   # stuff away all the elements under the h3
  end
end

Most of the useful element methods are in the mixins Hpricot::Traverse and Hpricot::Container::Trav.

Constant Summary

ATTR_RE = 
%r!\[ *(?:(@)([\w\(\)-]+)|([\w\(\)-]+\(\))) *([~\!\|\*$\^=]*) *'?"?([^'"]*)'?"? *\]!i
BRACK_RE = 
%r!(\[) *([^\]]*) *\]+!i
FUNC_RE = 
%r!(:)?([a-zA-Z0-9\*_-]*)\( *[\"']?([^ \)]*?)['\"]? *\)!
CUST_RE = 
%r!(:)([a-zA-Z0-9\*_-]*)()!
CATCH_RE = 
%r!([:\.#]*)([a-zA-Z0-9\*_-]+)!

Class Method Summary (collapse)

Instance Method Summary (collapse)

Methods inherited from Array

#_to_s, #clear, #clear_all, #dark?, #light?

Class Method Details

+ (Object) expand(ele1, ele2, excl = false)

Given two elements, attempt to gather an Elements array of everything between (and including) those two elements.



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# File 'lib/ext/hpricot/elements.rb', line 315

def self.expand(ele1, ele2, excl=false)
  ary = []
  offset = excl ? -1 : 0

  if ele1 and ele2
    # let's quickly take care of siblings
    if ele1.parent == ele2.parent
      ary = ele1.parent.children[ele1.node_position..(ele2.node_position+offset)]
    else
      # find common parent
      p, ele1_p = ele1, [ele1]
      ele1_p.unshift p while p.respond_to?(:parent) and p = p.parent
      p, ele2_p = ele2, [ele2]
      ele2_p.unshift p while p.respond_to?(:parent) and p = p.parent
      common_parent = ele1_p.zip(ele2_p).select { |p1, p2| p1 == p2 }.flatten.last

      child = nil
      if ele1 == common_parent
        child = ele2
      elsif ele2 == common_parent
        child = ele1
      end

      if child
        ary = common_parent.children[0..(child.node_position+offset)]
      end
    end
  end

  return Elements[*ary]
end

+ (Object) filter(nodes, expr, truth = true) 



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# File 'lib/ext/hpricot/elements.rb', line 270

def self.filter(nodes, expr, truth = true)
    until expr.empty?
        _, *m = *expr.match(/^(?:#{ATTR_RE}|#{BRACK_RE}|#{FUNC_RE}|#{CUST_RE}|#{CATCH_RE})/)
        break unless _

        expr = $'
        m.compact!
        if m[0] == '@'
            m[0] = "@#{m.slice!(2,1).join}"
        end

        if m[0] == '[' && m[1] =~ /^\d+$/
            m = [":", "nth", m[1].to_i-1]
        end

        if m[0] == ":" && m[1] == "not"
            nodes, = Elements.filter(nodes, m[2], false)
        elsif "#{m[0]}#{m[1]}" =~ /^(:even|:odd)$/
            new_nodes = []
            nodes.each_with_index {|n,i| new_nodes.push(n) if (i % 2 == (m[1] == "even" ? 0 : 1)) }
            nodes = new_nodes
        elsif "#{m[0]}#{m[1]}" =~ /^(:first|:last)$/
            nodes = [nodes.send(m[1])]
        else
            meth = "filter[#{m[0]}#{m[1]}]" unless m[0].empty?
            if meth and Traverse.method_defined? meth
                args = m[2..-1]
            else
                meth = "filter[#{m[0]}]"
                if Traverse.method_defined? meth
                    args = m[1..-1]
                end
            end
            args << -1
            nodes = Elements[*nodes.find_all do |x| 
                                  args[-1] += 1
                                  x.send(meth, *args) ? truth : !truth
                              end]
        end
    end
    [nodes, expr]
end

Instance Method Details

- (Object) add_class(class_name)

Adds the class to all matched elements.

(doc/"p").add_class("bacon")

Now all paragraphs will have class="bacon".



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# File 'lib/ext/hpricot/elements.rb', line 222

def add_class class_name
  each do |el|
    next unless el.respond_to? :get_attribute
    classes = el.get_attribute('class').to_s.split(" ")
    el.set_attribute('class', classes.push(class_name).uniq.join(" "))
  end
  self
end

- (Object) after(str = nil, &blk)

Just after each element in this list, add some HTML. Pass in an HTML str, which is turned into Hpricot elements.



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# File 'lib/ext/hpricot/elements.rb', line 150

def after(str = nil, &blk)
  each { |x| x.parent.insert_after x.make(str, &blk), x }
end

- (Object) append(str = nil, &blk)

Add to the end of the contents inside each element in this list. Pass in an HTML str, which is turned into Hpricot elements.



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# File 'lib/ext/hpricot/elements.rb', line 132

def append(str = nil, &blk)
  each { |x| x.html(x.children + x.make(str, &blk)) }
end

- (Object) at(expr, &blk) Also known as: %

Searches this list for the first element (or child of these elements) matching the CSS or XPath expression expr. Root is assumed to be the element scanned.

See Hpricot::Container::Trav.at for more.



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# File 'lib/ext/hpricot/elements.rb', line 67

def at(expr, &blk)
  search(expr, &blk).first
end

- (Object) attr(key, value = nil, &blk) Also known as: set

Gets and sets attributes on all matched elements.

Pass in a key on its own and this method will return the string value assigned to that attribute for the first elements. Or nil if the attribute isn't found.

doc.search("a").attr("href")
  #=> "http://hacketyhack.net/"

Or, pass in a key and value. This will set an attribute for all matched elements.

doc.search("p").attr("class", "basic")

You may also use a Hash to set a series of attributes:

(doc/"a").attr(:class => "basic", :href => "http://hackety.org/")

Lastly, a block can be used to rewrite an attribute based on the element it belongs to. The block will pass in an element. Return from the block the new value of the attribute.

records.attr("href") { |e| e['href'] + "#top" }

This example adds a #top anchor to each link.



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# File 'lib/ext/hpricot/elements.rb', line 201

def attr key, value = nil, &blk
  if value or blk
    each do |el|
      el.set_attribute(key, value || blk[el])
    end
    return self      
  end    
  if key.is_a? Hash
    key.each { |k,v| self.attr(k,v) }
    return self
  else
    return self[0].get_attribute(key)
  end
end

- (Object) before(str = nil, &blk)

Add some HTML just previous to each element in this list. Pass in an HTML str, which is turned into Hpricot elements.



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# File 'lib/ext/hpricot/elements.rb', line 144

def before(str = nil, &blk)
  each { |x| x.parent.insert_before x.make(str, &blk), x }
end

- (Object) empty

Empty the elements in this list, by removing their insides.

doc = Hpricot("<p> We have <i>so much</i> to say.</p>")
doc.search("i").empty
doc.to_html
  => "<p> We have <i></i> to say.</p>"


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# File 'lib/ext/hpricot/elements.rb', line 126

def empty
  each { |x| x.inner_html = nil }
end

- (Object) filter(expr) 



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# File 'lib/ext/hpricot/elements.rb', line 347

def filter(expr)
    nodes, = Elements.filter(self, expr)
    nodes
end

- (Object) inner_html(*string) Also known as: html, innerHTML

Returns an HTML fragment built of the contents of each element in this list.

If a HTML string is supplied, this method acts like inner_html=.



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# File 'lib/ext/hpricot/elements.rb', line 82

def inner_html(*string)
  if string.empty?
    map { |x| x.inner_html }.join
  else
    x = self.inner_html = string.pop || x
  end
end

- (Object) inner_html=(string) Also known as: html=, innerHTML=

Replaces the contents of each element in this list. Supply an HTML string, which is loaded into Hpricot objects and inserted into every element in this list.



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# File 'lib/ext/hpricot/elements.rb', line 95

def inner_html=(string)
  each { |x| x.inner_html = string }
end

- (Object) inner_text Also known as: text

Returns an string containing the text contents of each element in this list. All HTML tags are removed.



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# File 'lib/ext/hpricot/elements.rb', line 103

def inner_text
  map { |x| x.inner_text }.join
end

- (Object) not(expr) 



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# File 'lib/ext/hpricot/elements.rb', line 352

def not(expr)
    if expr.is_a? Traverse
        nodes = self - [expr]
    else
        nodes, = Elements.filter(self, expr, false)
    end
    nodes
end

- (Object) prepend(str = nil, &blk)

Add to the start of the contents inside each element in this list. Pass in an HTML str, which is turned into Hpricot elements.



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# File 'lib/ext/hpricot/elements.rb', line 138

def prepend(str = nil, &blk)
  each { |x| x.html(x.make(str, &blk) + x.children) }
end

- (Object) pretty_print(q) 



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# File 'lib/ext/hpricot/inspect.rb', line 6

def pretty_print(q)
  q.object_group(self) { super }
end

- (Object) remove

Remove all elements in this list from the document which contains them.

doc = Hpricot("<html>Remove this: <b>here</b></html>")
doc.search("b").remove
doc.to_html
  => "<html>Remove this: </html>"


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# File 'lib/ext/hpricot/elements.rb', line 115

def remove
  each { |x| x.parent.children.delete(x) }
end

- (Object) remove_attr(name)

Remove an attribute from each of the matched elements.

(doc/"input").remove_attr("disabled")


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# File 'lib/ext/hpricot/elements.rb', line 235

def remove_attr name
  each do |el|
    next unless el.respond_to? :remove_attribute
    el.remove_attribute(name)
  end
  self      
end

- (Object) remove_class(name = nil)

Removes a class from all matched elements.

(doc/"span").remove_class("lightgrey")

Or, to remove all classes:

(doc/"span").remove_class


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# File 'lib/ext/hpricot/elements.rb', line 251

def remove_class name = nil
  each do |el|
    next unless el.respond_to? :get_attribute
    if name
      classes = el.get_attribute('class').to_s.split(" ")
      el.set_attribute('class', (classes - [name]).uniq.join(" "))
    else
      el.remove_attribute("class")
    end
  end
  self      
end

- (Object) search(*expr, &blk) Also known as: /

Searches this list for any elements (or children of these elements) matching the CSS or XPath expression expr. Root is assumed to be the element scanned.

See Hpricot::Container::Trav.search for more.



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# File 'lib/ext/hpricot/elements.rb', line 58

def search(*expr,&blk)
  Elements[*map { |x| x.search(*expr,&blk) }.flatten.uniq]
end

- (Object) to_html Also known as: to_s

Convert this group of elements into a complete HTML fragment, returned as a string.



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# File 'lib/ext/hpricot/elements.rb', line 74

def to_html
  map { |x| x.output("") }.join
end

- (Object) wrap(str = nil, &blk)

Wraps each element in the list inside the element created by HTML str. If more than one element is found in the string, Hpricot locates the deepest spot inside the first element.

doc.search("a[@href]").
    wrap(%{<div class="link"><div class="link_inner"></div></div>})

This code wraps every link on the page inside a div.link and a div.link_inner nest.



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# File 'lib/ext/hpricot/elements.rb', line 162

def wrap(str = nil, &blk)
  each do |x|
    wrap = x.make(str, &blk)
    nest = wrap.detect { |w| w.respond_to? :children }
    unless nest
      raise "No wrapping element found."
    end
    x.parent.replace_child(x, wrap)
    nest = nest.children.first until nest.empty?
    nest.html([x])
  end
end