Parse HTML text into a tree of elements with selectors
###License
MIT; see ./doc/LICENSE
###Usage
Start off with
```lua
require("luarocks.loader")
local htmlparser = require("htmlparser")
```
Then, parse some html:
```lua
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:
```lua
local elements = root:select(selectorstring)
```
Or in shorthand:
```lua
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:
```lua
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
The tree elements provide, apart from :select and (), the following accessors:
- .name = the elements tagname
- .attributes = a table with keys and values for the element's attributes
- .id = the value of the element's id attribute, if present
- .classes = an array with the classes listed in element's class attribute, if any
- :getcontent() = the raw text between the opening and closing tags of the element
- .nodes = an array with the element's child elements
- .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
- .deeperelements = a table with a key for each distinct tagname in .deepernodes, containing a Set of all deeper element nodes with that name
- .deeperattributes = as .deeperelements, but keyed on attribute name
- .deeperids = as .deeperelements, but keyed on id value
- .deeperclasses = as .deeperelements, but keyed on class name
