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#LuaRock "htmlparser"

Parse HTML text into a tree of elements with selectors

##License MIT; see ./doc/LICENSE

##Usage Start off with

require("luarocks.loader")
local htmlparser = require("htmlparser")

Then, parse some html:

local root = htmlparser.parse(htmlstring)

The input to parse may be the contents of a complete html document, or any valid html snippet, as long as all tags are correctly opened and closed. Now, find sepcific contained elements by selecting:

local elements = root:select(selectorstring)

Or in shorthand:

local elements = root(selectorstring)

This wil return a Set of elements, all of which are of the same type as the root element, and thus support selecting as well, if ever needed:

for e in pairs(elements) do
	print(e.name)
	local subs = e(subselectorstring)
	for sub in pairs(subs) do
		print("", sub.name)
	end
end

The root element is a container for the top level elements in the parsed text, i.e. the <html> element in a parsed html document would be a child of the returned root element.

##Selectors Supported selectors are a subset of jQuery's selectors:

  • "*" all contained elements
  • "element" elements with the given tagname
  • "#id" elements with the given id attribute value
  • ".class" elements with the given classname in the class attribute
  • "[attribute]" elements with an attribute of the given name
  • "[attribute='value']" equals: elements with the given value for the attribute with the given name
  • "[attribute!='value']" not equals: elements without an attribute of the given name, or with that attribute, but with a value that is different from the given value
  • "[attribute|='value']" prefix: attribute's value is given value, or starts with given value, followed by a hyphen (-)
  • "[attribute*='value']" contains: attribute's value contains given value
  • "[attribute~='value']" word: attribute's value is a space-separated token, where one of the tokens is the given value
  • "[attribute^='value']" starts with: attribute's value starts with given value
  • "[attribute$='value']" ends with: attribute's value ends with given value
  • ":not(selector)"
  • "ancestor descendant"
  • "parent > child"

Selectors can be combined; e.g. ".class:not([attribute]) element.class"

###Limitations

  • Attribute values in selectors currently cannot contain any spaces, since space is interpreted as a delimiter between the ancestor and descendant, parent and >, or > and child parts of the selector
  • Likewise, for the parent > child relation, the spaces before and after the > are mandatory
  • <! elements are not parsed, including doctype and comments
  • Textnodes are not seperate entries in the tree, so the content of <p>line1<br />line2</p> is plainly "line1<br />line2"

##Examples See ./doc/samples.lua

##Element type All tree elements provide, apart from :select and (), the following accessors:

###Basic

  • .name the element's tagname
  • .attributes a table with keys and values for the element's attributes; {} if none
  • .id the value of the element's id attribute; nil if not present
  • .classes an array with the classes listed in element's class attribute; {} if none
  • :getcontent() the raw text between the opening and closing tags of the element; "" if none
  • .nodes an array with the element's child elements, {} if none
  • .parent the elements that contains this element; root.parent is nil

###Other

  • :gettext() the raw text of the complete element, starting with "<tagname" and ending with "/>"
  • .level how deep the element is in the tree; root level is 0
  • .root the root element of the tree; root.root is root
  • .deepernodes a Set containing all elements in the tree beneath this element, including this element's .nodes; {} if none
  • .deeperelements a table with a key for each distinct tagname in .deepernodes, containing a Set of all deeper element nodes with that name; {} in none
  • .deeperattributes as .deeperelements, but keyed on attribute name
  • .deeperids as .deeperelements, but keyed on id value
  • .deeperclasses as .deeperelements, but keyed on class name