lua-htmlparser/README.md

#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 specific 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

###Selectors

• "element"
• "#id"
• ".class"
• "[attribute]"
• "[attribute=value]"
• "[attribute!=value]"
• "[attribute|=value]"
• "[attribute*=value]"
• "[attribute~=value]"
• "[attribute^=value]"
• "[attribute$=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 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

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

• .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
• :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