| Safe Haskell | None |
|---|---|
| Language | Haskell98 |
Text.XmlHtml
Description
Parsers and renderers for XML and HTML 5. Although the formats are treated differently, the data types used by each are the same, which makes it easy to write code that works with the element structure of either XML or HTML 5 documents.
Limitations:
- The XML parser does not parse internal DOCTYPE subsets. They are just stored as blocks of text, with minimal scanning done to match quotes and brackets to determine the end.
- Since DTDs are not parsed, the XML parser fails on entity references, except for those defined internally. You cannot use this library for parsing XML documents with entity references outside the predefined set.
- The HTML 5 parser is not a compliant HTML parser. Instead, it is a parser for valid HTML 5 content. It should only be used on content that you have reason to believe is probably correct, since the compatibility features of HTML 5 are missing. This is the wrong library on which to build a web spider.
- Both parsers accept fragments of documents, by which is meant that they do not enforce the top-level structure of the document. Files may contain more than one root element, for example.
- data Document
- = XmlDocument {
- docEncoding :: !Encoding
- docType :: !(Maybe DocType)
- docContent :: ![Node]
- | HtmlDocument {
- docEncoding :: !Encoding
- docType :: !(Maybe DocType)
- docContent :: ![Node]
- = XmlDocument {
- data Node
- = TextNode !Text
- | Comment !Text
- | Element {
- elementTag :: !Text
- elementAttrs :: ![(Text, Text)]
- elementChildren :: ![Node]
- data DocType = DocType !Text !ExternalID !InternalSubset
- data ExternalID
- data InternalSubset
- data Encoding
- isTextNode :: Node -> Bool
- isComment :: Node -> Bool
- isElement :: Node -> Bool
- tagName :: Node -> Maybe Text
- getAttribute :: Text -> Node -> Maybe Text
- hasAttribute :: Text -> Node -> Bool
- setAttribute :: Text -> Text -> Node -> Node
- nodeText :: Node -> Text
- childNodes :: Node -> [Node]
- childElements :: Node -> [Node]
- childElementsTag :: Text -> Node -> [Node]
- childElementTag :: Text -> Node -> Maybe Node
- descendantNodes :: Node -> [Node]
- descendantElements :: Node -> [Node]
- descendantElementsTag :: Text -> Node -> [Node]
- descendantElementTag :: Text -> Node -> Maybe Node
- parseXML :: String -> ByteString -> Either String Document
- parseHTML :: String -> ByteString -> Either String Document
- render :: Document -> Builder
- renderXmlFragment :: Encoding -> [Node] -> Builder
- renderHtmlFragment :: Encoding -> [Node] -> Builder
- renderDocType :: Encoding -> Maybe DocType -> Builder
Types
Represents a document fragment, including the format, encoding, and document type declaration as well as its content.
Constructors
| XmlDocument | |
Fields
| |
| HtmlDocument | |
Fields
| |
A node of a document structure. A node can be text, a comment, or an element. XML processing instructions are intentionally omitted as a simplification, and CDATA and plain text are both text nodes, since they ought to be semantically interchangeable.
Constructors
| TextNode !Text | |
| Comment !Text | |
| Element | |
Fields
| |
A document type declaration. Note that DTD internal subsets are currently unimplemented.
Constructors
| DocType !Text !ExternalID !InternalSubset |
data ExternalID Source #
An external ID, as in a document type declaration. This can be a SYSTEM identifier, or a PUBLIC identifier, or can be omitted.
Instances
data InternalSubset Source #
The internal subset is unparsed, but preserved in case it's actually wanted.
Constructors
| InternalText !Text | |
| NoInternalSubset |
Instances
The character encoding of a document. Currently only the required character encodings are implemented.
Manipulating documents
isTextNode :: Node -> Bool Source #
Determines whether the node is text or not.
tagName :: Node -> Maybe Text Source #
Gives the tag name of an element, or Nothing if the node isn't an
element.
setAttribute :: Text -> Text -> Node -> Node Source #
Sets the attribute name to the given value. If the Node is not an
element, this is the identity.
childNodes :: Node -> [Node] Source #
Gives the child nodes of the given node. Only elements have child nodes.
childElements :: Node -> [Node] Source #
Gives the child elements of the given node.
childElementsTag :: Text -> Node -> [Node] Source #
Gives all of the child elements of the node with the given tag name.
childElementTag :: Text -> Node -> Maybe Node Source #
Gives the first child element of the node with the given tag name,
or Nothing if there is no such child element.
descendantNodes :: Node -> [Node] Source #
Gives the descendants of the given node in the order that they begin in the document.
descendantElements :: Node -> [Node] Source #
Gives the descendant elements of the given node, in the order that their start tags appear in the document.
descendantElementsTag :: Text -> Node -> [Node] Source #
Gives the descendant elements with a given tag name.
descendantElementTag :: Text -> Node -> Maybe Node Source #
Gives the first descendant element of the node with the given tag name,
or Nothing if there is no such element.
Parsing
Arguments
| :: String | Name of document source (perhaps a filename) for error messages |
| -> ByteString | Document contents |
| -> Either String Document | The document or an error message |
Parses the given XML fragment.
Arguments
| :: String | Name of document source (perhaps a filename) for error messages |
| -> ByteString | Document contents |
| -> Either String Document | The document or an error message |
Parses the given HTML fragment. This enables HTML quirks mode, which changes the parsing algorithm to parse valid HTML 5 documents correctly.
Rendering
renderXmlFragment :: Encoding -> [Node] -> Builder Source #
Function for rendering XML nodes without the overhead of creating a Document structure.