Safe Haskell	None

Text.Blaze

Contents

Important types.
Creating attributes.
Converting values to Markup.
Creating tags.
Converting values to attribute values.
Setting attributes
Modifiying Markup trees

Description

BlazeMarkup is a markup combinator library. It provides a way to embed markup languages like HTML and SVG in Haskell in an efficient and convenient way, with a light-weight syntax.

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

 {-# 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 (renderMarkup)

Now, you can describe pages using the imported combinators.

 page1 :: Markup
 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 BlazeMarkup syntax."
         ul $ mapM_ (li . toMarkup . show) [1, 2, 3]

The resulting HTML can now be extracted using:

 renderMarkup page1

Synopsis

Important types.

type Markup = MarkupM ()Source

Simplification of the MarkupM datatype.

data Tag Source

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

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 BlazeMarkup using this funcion. The above fragment could be described using BlazeMarkup 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 Markup.

class ToMarkup a whereSource

Class allowing us to use a single function for Markup values

Methods

toMarkup :: a -> Markup Source

Convert a value to Markup.

preEscapedToMarkup :: a -> Markup Source

Convert a value to Markup without escaping

Instances

ToMarkup Bool
ToMarkup Char
ToMarkup Double
ToMarkup Float
ToMarkup Int
ToMarkup Integer
ToMarkup String
ToMarkup Text
ToMarkup Text
ToMarkup Markup
ToMarkup [Markup]

unsafeByteString Source

Arguments

:: ByteString	Value to insert.
-> Markup	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
-> Markup	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 attribute value

preEscapedToValue :: a -> AttributeValue Source

Convert a value to an attribute value without escaping

Instances

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

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>

Modifiying Markup trees

contents :: MarkupM a -> MarkupM bSource

Take only the text content of an HTML tree.

 contents $ do
     p ! $ "Hello "
     p ! $ "Word!"

Result:

 Hello World!