blob: 9f929570c891abcf84da62af587baedceb1a35ad (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
|
# The Parser Model
The parser model here follows the model in section
[8.2.1](http://www.w3.org/TR/2012/CR-html5-20121217/syntax.html#parsing)
of the HTML5 specification, though we do not assume a networking layer.
[ InputStream ] // Generic support for reading input.
||
[ Scanner ] // Breaks down the stream into characters.
||
[ Tokenizer ] // Groups characters into syntactic
||
[ Tree Builder ] // Organizes units into a tree of objects
||
[ DOM Document ] // The final state of the parsed document.
## InputStream
This is an interface with at least two concrete implementations:
- StringInputStream: Reads an HTML5 string.
- FileInputStream: Reads an HTML5 file.
## Scanner
This is a mechanical piece of the parser.
## Tokenizer
This follows section 8.4 of the HTML5 spec. It is (roughly) a recursive
descent parser. (Though there are plenty of optimizations that are less
than purely functional.
## EventHandler and DOMTree
EventHandler is the interface for tree builders. Since not all
implementations will necessarily build trees, we've chosen a more
generic name.
The event handler emits tokens during tokenization.
The DOMTree is an event handler that builds a DOM tree. The output of
the DOMTree builder is a DOMDocument.
## DOMDocument
PHP has a DOMDocument class built-in (technically, it's part of libxml.)
We use that, thus rendering the output of this process compatible with
SimpleXML, QueryPath, and many other XML/HTML processing tools.
For cases where the HTML5 is a fragment of a HTML5 document a
DOMDocumentFragment is returned instead. This is another built-in class.
|
