Safe Haskell	Safe-Infered

Text.Blaze

Contents

Important types.
Creating attributes.
Converting values to HTML.
Creating tags.
Converting values to attribute values.
Setting attributes

Description

BlazeHtml is an HTML combinator library. It provides a way to embed HTML in Haskell in an efficient and convenient way, with a light-weight syntax.

To use the library, one needs to import a set of HTML combinators. For example, you can use HTML 4 Strict.

 {-# LANGUAGE OverloadedStrings #-}
 import Prelude hiding (head, id, div)
 import Text.Blaze.Html4.Strict hiding (map)
 import Text.Blaze.Html4.Strict.Attributes hiding (title)

To render the page later on, you need a so called Renderer. The recommended renderer is an UTF-8 renderer which produces a lazy bytestring.

 import Text.Blaze.Renderer.Utf8 (renderHtml)

Now, you can describe pages using the imported combinators.

 page1 :: Html
 page1 = html $ do
     head $ do
         title "Introduction page."
         link ! rel "stylesheet" ! type_ "text/css" ! href "screen.css"
     body $ do
         div ! id "header" $ "Syntax"
         p "This is an example of BlazeHtml syntax."
         ul $ mapM_ (li . toHtml . show) [1, 2, 3]

The resulting HTML can now be extracted using:

 renderHtml page1

Synopsis

Important types.

type Html = HtmlM ()Source

Simplification of the HtmlM datatype.

data Tag Source

Type for an HTML tag. This can be seen as an internal string type used by BlazeHtml.

Instances

IsString Tag

data Attribute Source

Type for an attribute.

Instances

Monoid Attribute

data AttributeValue Source

The type for the value part of an attribute.

Instances

IsString AttributeValue
Monoid AttributeValue
ToValue AttributeValue

Creating attributes.

dataAttribute Source

Arguments

:: Tag	Name of the attribute.
-> AttributeValue	Value for the attribute.
-> Attribute	Resulting HTML attribute.

From HTML 5 onwards, the user is able to specify custom data attributes.

An example:

 <p data-foo="bar">Hello.</p>

We support this in BlazeHtml using this funcion. The above fragment could be described using BlazeHtml with:

 p ! dataAttribute "foo" "bar" $ "Hello."

customAttribute Source

Arguments

:: Tag	Name of the attribute
-> AttributeValue	Value for the attribute
-> Attribute	Resulting HTML attribtue

Create a custom attribute. This is not specified in the HTML spec, but some JavaScript libraries rely on it.

An example:

 <select dojoType="select">foo</select>

Can be produced using:

 select ! customAttribute "dojoType" "select" $ "foo"

Converting values to HTML.

class ToHtml a whereSource

Class allowing us to use a single function for HTML values

Methods

toHtml :: a -> Html Source

Convert a value to HTML.

Instances

ToHtml Bool
ToHtml Char
ToHtml Double
ToHtml Float
ToHtml Int
ToHtml Integer
ToHtml String
ToHtml Text
ToHtml Text
ToHtml Html
ToHtml [Html]

text Source

Arguments

:: Text	Text to render.
-> Html	Resulting HTML fragment.

Render text. Functions like these can be used to supply content in HTML.

preEscapedText Source

Arguments

:: Text	Text to insert
-> Html	Resulting HTML fragment

Render text without escaping.

lazyText Source

Arguments

:: Text	Text to insert
-> Html	Resulting HTML fragment

A variant of text for lazy Text.

preEscapedLazyText Source

Arguments

:: Text	Text to insert
-> Html	Resulting HTML fragment

A variant of preEscapedText for lazy Text

string Source

Arguments

:: String	String to insert.
-> Html	Resulting HTML fragment.

Create an HTML snippet from a String.

preEscapedString Source

Arguments

:: String	String to insert.
-> Html	Resulting HTML fragment.

Create an HTML snippet from a String without escaping

unsafeByteString Source

Arguments

:: ByteString	Value to insert.
-> Html	Resulting HTML fragment.

Insert a ByteString. This is an unsafe operation:

The ByteString could have the wrong encoding.
The ByteString might contain illegal HTML characters (no escaping is done).

unsafeLazyByteString Source

Arguments

:: ByteString	Value to insert
-> Html	Resulting HTML fragment

Insert a lazy ByteString. See unsafeByteString for reasons why this is an unsafe operation.

Creating tags.

textTag Source

Arguments

:: Text	Text to create a tag from
-> Tag	Resulting tag

Create a Tag from some Text.

stringTag Source

Arguments

:: String	String to create a tag from
-> Tag	Resulting tag

Create a Tag from a String.

Converting values to attribute values.

class ToValue a whereSource

Class allowing us to use a single function for attribute values

Methods

toValue :: a -> AttributeValue Source

Convert a value to an HTML attribute value

Instances

ToValue Bool
ToValue Char
ToValue Double
ToValue Float
ToValue Int
ToValue Integer
ToValue String
ToValue Text
ToValue Text
ToValue AttributeValue

textValue Source

Arguments

:: Text	The actual value.
-> AttributeValue	Resulting attribute value.

Render an attribute value from Text.

preEscapedTextValue Source

Arguments

:: Text	The actual value
-> AttributeValue	Resulting attribute value

Render an attribute value from Text without escaping.

lazyTextValue Source

Arguments

:: Text	The actual value
-> AttributeValue	Resulting attribute value

A variant of textValue for lazy Text

preEscapedLazyTextValue Source

Arguments

:: Text	The actual value
-> AttributeValue	Resulting attribute value

A variant of preEscapedTextValue for lazy Text

stringValue :: String -> AttributeValue Source

Create an attribute value from a String.

preEscapedStringValue :: String -> AttributeValue Source

Create an attribute value from a String without escaping.

unsafeByteStringValue Source

Arguments

:: ByteString	ByteString value
-> AttributeValue	Resulting attribute value

Create an attribute value from a ByteString. See unsafeByteString for reasons why this might not be a good idea.

unsafeLazyByteStringValue Source

Arguments

:: ByteString	ByteString value
-> AttributeValue	Resulting attribute value

Create an attribute value from a lazy ByteString. See unsafeByteString for reasons why this might not be a good idea.

Setting attributes

(!) :: Attributable h => h -> Attribute -> hSource

Apply an attribute to an element.

Example:

 img ! src "foo.png"

Result:

 <img src="foo.png" />

This can be used on nested elements as well.

Example:

 p ! style "float: right" $ "Hello!"

Result:

 <p style="float: right">Hello!</p>