blaze-markup-0.6.1.0: A blazingly fast markup combinator library for Haskell

Safe HaskellNone

Text.Blaze

Contents

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

data Attribute Source

Type for an attribute.

Instances

data AttributeValue Source

The type for the value part of an attribute.

Instances

Creating attributes.

dataAttributeSource

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."

customAttributeSource

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 -> MarkupSource

Convert a value to Markup.

preEscapedToMarkup :: a -> MarkupSource

Convert a value to Markup without escaping

Instances

unsafeByteStringSource

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).

unsafeLazyByteStringSource

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.

textTagSource

Arguments

:: Text

Text to create a tag from

-> Tag

Resulting tag

Create a Tag from some Text.

stringTagSource

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 -> AttributeValueSource

Convert a value to an attribute value

preEscapedToValue :: a -> AttributeValueSource

Convert a value to an attribute value without escaping

Instances

unsafeByteStringValueSource

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.

unsafeLazyByteStringValueSource

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>

(!?) :: Attributable h => h -> (Bool, Attribute) -> hSource

Shorthand for setting an attribute depending on a conditional.

Example: 

 p !? (isBig, A.class "big") $ "Hello"

Gives the same result as: 

 (if isBig then p ! A.class "big" else p) "Hello"

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!