54 lines
1.7 KiB
Markdown
54 lines
1.7 KiB
Markdown
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# The Parser Model
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The parser model here follows the model in section
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[8.2.1](http://www.w3.org/TR/2012/CR-html5-20121217/syntax.html#parsing)
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of the HTML5 specification, though we do not assume a networking layer.
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[ InputStream ] // Generic support for reading input.
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[ Scanner ] // Breaks down the stream into characters.
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[ Tokenizer ] // Groups characters into syntactic
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[ Tree Builder ] // Organizes units into a tree of objects
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[ DOM Document ] // The final state of the parsed document.
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## InputStream
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This is an interface with at least two concrete implementations:
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- StringInputStream: Reads an HTML5 string.
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- FileInputStream: Reads an HTML5 file.
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## Scanner
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This is a mechanical piece of the parser.
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## Tokenizer
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This follows section 8.4 of the HTML5 spec. It is (roughly) a recursive
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descent parser. (Though there are plenty of optimizations that are less
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than purely functional.
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## EventHandler and DOMTree
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EventHandler is the interface for tree builders. Since not all
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implementations will necessarily build trees, we've chosen a more
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generic name.
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The event handler emits tokens during tokenization.
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The DOMTree is an event handler that builds a DOM tree. The output of
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the DOMTree builder is a DOMDocument.
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## DOMDocument
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PHP has a DOMDocument class built-in (technically, it's part of libxml.)
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We use that, thus rendering the output of this process compatible with
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SimpleXML, QueryPath, and many other XML/HTML processing tools.
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For cases where the HTML5 is a fragment of a HTML5 document a
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DOMDocumentFragment is returned instead. This is another built-in class.
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