lucid2: Clear to write, read and edit DSL for HTML

[ bsd3, library, web ] [ Propose Tags ]

Clear to write, read and edit DSL for HTML.

  • Names are consistent, and do not conflict with base or are keywords (all have suffix _)

  • Same combinator can be used for attributes and elements (e.g. style_)

  • For more, read the blog post

See the Lucid module for more documentation.

This package is the newer version of lucid.


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Versions [RSS] 0.0.20220508, 0.0.20220509, 0.0.20220526
Change log CHANGELOG.md
Dependencies base (>=4.8 && <4.17), blaze-builder, bytestring (>=0.10.12.0), containers (>=0.6.5.1), mtl (>=2.2.2), text (>=1.2.4.1), transformers (>=0.5.6.2) [details]
License BSD-3-Clause
Copyright 2014-2022 Chris Done
Author Chris Done
Maintainer lucid2@chrisdone.com
Category Web
Home page https://github.com/chrisdone/lucid
Source repo head: git clone https://github.com/chrisdone/lucid.git
Uploaded by ChrisDone at 2022-05-26T08:05:23Z
Distributions NixOS:0.0.20220526, Stackage:0.0.20220526
Downloads 107 total (21 in the last 30 days)
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Status Docs available [build log]
Last success reported on 2022-05-26 [all 1 reports]

Readme for lucid2-0.0.20220526

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lucid2

Note: For a list of changes from lucid1 to lucid2, see CHANGELOG.md

Clear to write, read and edit DSL for writing HTML

Table of Contents

Version

This is version 2 of the lucid package, according to the Immutable Publishing Policy.

There never be any breaking changes made to this package.

Introduction

HTML terms in Lucid are written with a postfix ‘_’ to indicate data rather than code. Some examples:

p_, class_, table_, style_

See Lucid.Html5 for a complete list of Html5 combinators.

Plain text is written using the OverloadedStrings and ExtendedDefaultRules extensions, and is automatically escaped:

λ> "123 < 456" :: Html ()
123 &lt; 456

Elements nest by function application:

λ> table_ (tr_ (td_ (p_ "Hello, World!"))) :: Html ()
<table><tr><td><p>Hello, World!</p></td></tr></table>

Elements are juxtaposed via monoidal append:

λ> p_ "hello" <> p_ "sup" :: Html ()
<p>hello</p><p>sup</p>

Or monadic sequencing:

λ> div_ (do p_ "hello"; p_ "sup") :: Html ()
<div><p>hello</p><p>sup</p></div>

Attributes are set by providing an argument list:

λ> p_ [class_ "brand"] "Lucid Inc" :: Html ()
<p class="brand">Lucid Inc</p>

Here is a fuller example of Lucid:

table_ [rows_ "2"]
       (tr_ (do td_ [class_ "top",colspan_ "2",style_ "color:red"]
                    (p_ "Hello, attributes!")
                td_ "yay!"))
<table rows="2">
  <tr>
    <td style="color:red" colspan="2" class="top">
      <p>Hello, attributes!</p>
    </td>
    <td>yay!</td>
  </tr>
</table>

Rendering

For proper rendering you can easily run some HTML immediately with:

λ> renderText (p_ "Hello!")
"<p>Hello!</p>"

Or to bytes:

λ> renderBS (p_ [style_ "color:red"] "Hello!")
"<p style=\"color:red\">Hello!</p>"

For ease of use in GHCi, there is a Show instance, as demonstrated above.

If the above rendering functions aren't suited for your purpose, you can run the monad directly via execHtml and use the more low-level blaze Builder, which has a plethora of output modes in Blaze.ByteString.Builder.

See the documentation for the Lucid module for information about using it as a monad transformer.

Good to know

  • Attributes are escaped, so you cannot write arbitrary JavaScript in attributes. Instead, do something like onclick_ "foo()".
  • Attributes are rendered in the order that they are written in your Haskell code.

Transforming

You can use lift to call parent monads.

λ> runReader (renderTextT (html_ (body_ (do name <- lift ask
                                            p_ [class_ "name"] (toHtml name)))))
             ("Chris" :: String)
"<html><body><p class=\"name\">Chris</p></body></html>"