Module HTML.curry

Library for HTML and CGI programming. This paper contains a description of the basic ideas behind this library.

The installation of a cgi script written with this library can be done by the command

makecurrycgi -m initialForm -o /home/joe/public_html/prog.cgi prog

where prog is the name of the Curry program with the cgi script, /home/joe/public_html/prog.cgi is the desired location of the compiled cgi script, and initialForm is the Curry expression (of type IO HtmlForm) computing the HTML form (where makecurrycgi is a shell script stored in pakcshome/bin).

Author: Michael Hanus (with extensions by Bernd Brassel and Marco Comini)

Version: February 2014

Summary of exported operations:

defaultEncoding :: String   
The default encoding used in generated web pages.
idOfCgiRef :: CgiRef -> String   
Internal identifier of a CgiRef (intended only for internal use in other libraries!).
formEnc :: String -> FormParam   
An encoding scheme for a HTML form.
formCSS :: String -> FormParam   
A URL for a CSS file for a HTML form.
formMetaInfo :: [(String,String)] -> FormParam   
Meta information for a HTML form.
formBodyAttr :: (String,String) -> FormParam   
Optional attribute for the body element of the HTML form.
form :: String -> [HtmlExp] -> HtmlForm   
A basic HTML form for active web pages with the default encoding and a default background.
standardForm :: String -> [HtmlExp] -> HtmlForm   
A standard HTML form for active web pages where the title is included in the body as the first header.
cookieForm :: String -> [(String,String)] -> [HtmlExp] -> HtmlForm   
An HTML form with simple cookies.
addCookies :: [(String,String)] -> HtmlForm -> HtmlForm   
Add simple cookie to HTML form.
answerText :: String -> HtmlForm   
A textual result instead of an HTML form as a result for active web pages.
answerEncText :: String -> String -> HtmlForm   
A textual result instead of an HTML form as a result for active web pages where the encoding is given as the first parameter.
addFormParam :: HtmlForm -> FormParam -> HtmlForm   
Adds a parameter to an HTML form.
redirect :: Int -> String -> HtmlForm -> HtmlForm   
Adds redirection to given HTML form.
expires :: Int -> HtmlForm -> HtmlForm   
Adds expire time to given HTML form.
addSound :: String -> Bool -> HtmlForm -> HtmlForm   
Adds sound to given HTML form.
pageEnc :: String -> PageParam   
An encoding scheme for a HTML page.
pageCSS :: String -> PageParam   
A URL for a CSS file for a HTML page.
pageMetaInfo :: [(String,String)] -> PageParam   
Meta information for a HTML page.
pageLinkInfo :: [(String,String)] -> PageParam   
Link information for a HTML page.
pageBodyAttr :: (String,String) -> PageParam   
Optional attribute for the body element of the web page.
page :: String -> [HtmlExp] -> HtmlPage   
A basic HTML web page with the default encoding.
standardPage :: String -> [HtmlExp] -> HtmlPage   
A standard HTML web page where the title is included in the body as the first header.
addPageParam :: HtmlPage -> PageParam -> HtmlPage   
Adds a parameter to an HTML page.
htxt :: String -> HtmlExp   
Basic text as HTML expression.
htxts :: [String] -> [HtmlExp]   
A list of strings represented as a list of HTML expressions.
hempty :: HtmlExp   
An empty HTML expression.
nbsp :: HtmlExp   
Non breaking Space
h1 :: [HtmlExp] -> HtmlExp   
Header 1
h2 :: [HtmlExp] -> HtmlExp   
Header 2
h3 :: [HtmlExp] -> HtmlExp   
Header 3
h4 :: [HtmlExp] -> HtmlExp   
Header 4
h5 :: [HtmlExp] -> HtmlExp   
Header 5
par :: [HtmlExp] -> HtmlExp   
Paragraph
emphasize :: [HtmlExp] -> HtmlExp   
Emphasize
strong :: [HtmlExp] -> HtmlExp   
Strong (more emphasized) text.
bold :: [HtmlExp] -> HtmlExp   
Boldface
italic :: [HtmlExp] -> HtmlExp   
Italic
code :: [HtmlExp] -> HtmlExp   
Program code
center :: [HtmlExp] -> HtmlExp   
Centered text
blink :: [HtmlExp] -> HtmlExp   
Blinking text
teletype :: [HtmlExp] -> HtmlExp   
Teletype font
pre :: [HtmlExp] -> HtmlExp   
Unformatted input, i.e., keep spaces and line breaks and don't quote special characters.
verbatim :: String -> HtmlExp   
Verbatim (unformatted), special characters (<,>,&,") are quoted.
address :: [HtmlExp] -> HtmlExp   
Address
href :: String -> [HtmlExp] -> HtmlExp   
Hypertext reference
anchor :: String -> [HtmlExp] -> HtmlExp   
An anchored text with a hypertext reference inside a document.
ulist :: [[HtmlExp]] -> HtmlExp   
Unordered list
olist :: [[HtmlExp]] -> HtmlExp   
Ordered list
litem :: [HtmlExp] -> HtmlExp   
A single list item (usually not explicitly used)
dlist :: [([HtmlExp],[HtmlExp])] -> HtmlExp   
Description list
table :: [[[HtmlExp]]] -> HtmlExp   
Table with a matrix of items where each item is a list of HTML expressions.
headedTable :: [[[HtmlExp]]] -> HtmlExp   
Similar to table but introduces header tags for the first row.
addHeadings :: HtmlExp -> [[HtmlExp]] -> HtmlExp   
Add a row of items (where each item is a list of HTML expressions) as headings to a table.
hrule :: HtmlExp   
Horizontal rule
breakline :: HtmlExp   
Break a line
image :: String -> String -> HtmlExp   
Image
styleSheet :: String -> HtmlExp   
Defines a style sheet to be used in this HTML document.
style :: String -> [HtmlExp] -> HtmlExp   
Provides a style for HTML elements.
textstyle :: String -> String -> HtmlExp   
Provides a style for a basic text.
blockstyle :: String -> [HtmlExp] -> HtmlExp   
Provides a style for a block of HTML elements.
inline :: [HtmlExp] -> HtmlExp   
Joins a list of HTML elements into a single HTML element.
block :: [HtmlExp] -> HtmlExp   
Joins a list of HTML elements into a block.
button :: String -> ((CgiRef -> String) -> IO HtmlForm) -> HtmlExp   
Submit button with a label string and an event handler
resetbutton :: String -> HtmlExp   
Reset button with a label string
imageButton :: String -> ((CgiRef -> String) -> IO HtmlForm) -> HtmlExp   
Submit button in form of an imag.
textfield :: CgiRef -> String -> HtmlExp   
Input text field with a reference and an initial contents
password :: CgiRef -> HtmlExp   
Input text field (where the entered text is obscured) with a reference
textarea :: CgiRef -> (Int,Int) -> String -> HtmlExp   
Input text area with a reference, height/width, and initial contents
checkbox :: CgiRef -> String -> HtmlExp   
A checkbox with a reference and a value.
checkedbox :: CgiRef -> String -> HtmlExp   
A checkbox that is initially checked with a reference and a value.
radio_main :: CgiRef -> String -> HtmlExp   
A main button of a radio (initially "on") with a reference and a value.
radio_main_off :: CgiRef -> String -> HtmlExp   
A main button of a radio (initially "off") with a reference and a value.
radio_other :: CgiRef -> String -> HtmlExp   
A further button of a radio (initially "off") with a reference (identical to the main button of this radio) and a value.
selection :: CgiRef -> [(String,String)] -> HtmlExp   
A selection button with a reference and a list of name/value pairs.
selectionInitial :: CgiRef -> [(String,String)] -> Int -> HtmlExp   
A selection button with a reference, a list of name/value pairs, and a preselected item in this list.
multipleSelection :: CgiRef -> [(String,String,Bool)] -> HtmlExp   
A selection button with a reference and a list of name/value/flag pairs.
hiddenfield :: String -> String -> HtmlExp   
A hidden field to pass a value referenced by a fixed name.
htmlQuote :: String -> String   
Quotes special characters (<,>,&,", umlauts) in a string as HTML special characters.
htmlIsoUmlauts :: String -> String   
Translates umlauts in iso-8859-1 encoding into HTML special characters.
addAttr :: HtmlExp -> (String,String) -> HtmlExp   
Adds an attribute (name/value pair) to an HTML element.
addAttrs :: HtmlExp -> [(String,String)] -> HtmlExp   
Adds a list of attributes (name/value pair) to an HTML element.
addClass :: HtmlExp -> String -> HtmlExp   
Adds a class attribute to an HTML element.
showHtmlExps :: [HtmlExp] -> String   
Transforms a list of HTML expressions into string representation.
showHtmlExp :: HtmlExp -> String   
Transforms a single HTML expression into string representation.
showHtmlPage :: HtmlPage -> String   
Transforms HTML page into string representation.
getUrlParameter :: IO String   
Gets the parameter attached to the URL of the script.
urlencoded2string :: String -> String   
Translates urlencoded string into equivalent ASCII string.
string2urlencoded :: String -> String   
Translates arbitrary strings into equivalent urlencoded string.
getCookies :: IO [(String,String)]   
Gets the cookies sent from the browser for the current CGI script.
coordinates :: (CgiRef -> String) -> Maybe (Int,Int)   
For image buttons: retrieve the coordinates where the user clicked within the image.
runFormServerWithKey :: String -> String -> IO HtmlForm -> IO ()   
The server implementing an HTML form (possibly containing input fields).
runFormServerWithKeyAndFormParams :: String -> String -> [FormParam] -> IO HtmlForm -> IO ()   
The server implementing an HTML form (possibly containing input fields).
showLatexExps :: [HtmlExp] -> String   
Transforms HTML expressions into LaTeX string representation.
showLatexExp :: HtmlExp -> String   
Transforms an HTML expression into LaTeX string representation.
htmlSpecialChars2tex :: String -> String   
Convert special HTML characters into their LaTeX representation, if necessary.
showLatexDoc :: [HtmlExp] -> String   
Transforms HTML expressions into a string representation of a complete LaTeX document.
showLatexDocWithPackages :: [HtmlExp] -> [String] -> String   
Transforms HTML expressions into a string representation of a complete LaTeX document.
showLatexDocs :: [[HtmlExp]] -> String   
Transforms a list of HTML expressions into a string representation of a complete LaTeX document where each list entry appears on a separate page.
showLatexDocsWithPackages :: [[HtmlExp]] -> [String] -> String   
Transforms a list of HTML expressions into a string representation of a complete LaTeX document where each list entry appears on a separate page.
germanLatexDoc :: [HtmlExp] -> String   
show german latex document
intForm :: IO HtmlForm -> IO ()   
Execute an HTML form in "interactive" mode.
intFormMain :: String -> String -> String -> String -> Bool -> String -> IO HtmlForm -> IO ()   
Execute an HTML form in "interactive" mode with various parameters.

Exported datatypes:


CgiEnv

The type for representing cgi environments (i.e., mappings from cgi references to the corresponding values of the input elements).

Type synonym: CgiEnv = CgiRef -> String


HtmlHandler

The type of event handlers in HTML forms.

Type synonym: HtmlHandler = (CgiRef -> String) -> IO HtmlForm


CgiRef

The (abstract) data type for representing references to input elements in HTML forms.

Constructors:


HtmlExp

The data type for representing HTML expressions.

Constructors:

HtmlText :: String -> HtmlExp

HtmlText s : a text string without any further structure

HtmlStruct :: String -> [(String,String)] -> [HtmlExp] -> HtmlExp

HtmlStruct t as hs : a structure with a tag, attributes, and HTML expressions inside the structure

HtmlCRef :: HtmlExp -> CgiRef -> HtmlExp

HtmlCRef h ref : an input element (described by the first argument) with a cgi reference

HtmlEvent :: HtmlExp -> ((CgiRef -> String) -> IO HtmlForm) -> HtmlExp

HtmlEvent h hdlr : an input element (first arg) with an associated event handler (tpyically, a submit button)


HtmlForm

The data type for representing HTML forms (active web pages) and return values of HTML forms.

Constructors:

HtmlForm :: String -> [FormParam] -> [HtmlExp] -> HtmlForm

HtmlForm t ps hs : an HTML form with title t, optional parameters (e.g., cookies) ps, and contents hs

HtmlAnswer :: String -> String -> HtmlForm

HtmlAnswer t c : an answer in an arbitrary format where t is the content type (e.g., "text/plain") and c is the contents


FormParam

The possible parameters of an HTML form. The parameters of a cookie (FormCookie) are its name and value and optional parameters (expiration date, domain, path (e.g., the path "/" makes the cookie valid for all documents on the server), security) which are collected in a list.

Constructors:

FormCookie :: String -> String -> [CookieParam] -> FormParam

FormCookie name value params : a cookie to be sent to the client's browser

FormCSS :: String -> FormParam

FormCSS s : a URL for a CSS file for this form

FormJScript :: String -> FormParam

FormJScript s : a URL for a Javascript file for this form

FormOnSubmit :: String -> FormParam

FormOnSubmit s : a JavaScript statement to be executed when the form is submitted (i.e., <form ... onsubmit="s">)

FormTarget :: String -> FormParam

FormTarget s : a name of a target frame where the output of the script should be represented (should only be used for scripts running in a frame)

FormEnc :: String -> FormParam

FormEnc : the encoding scheme of this form

FormMeta :: [(String,String)] -> FormParam

FormMeta as : meta information (in form of attributes) for this form

HeadInclude :: HtmlExp -> FormParam

HeadInclude he : HTML expression to be included in form header

MultipleHandlers :: FormParam

MultipleHandlers : indicates that the event handlers of the form can be multiply used (i.e., are not deleted if the form is submitted so that they are still available when going back in the browser; but then there is a higher risk that the web server process might overflow with unused events); the default is a single use of event handlers, i.e., one cannot use the back button in the browser and submit the same form again (which is usually a reasonable behavior to avoid double submissions of data).

BodyAttr :: (String,String) -> FormParam

BodyAttr ps : optional attribute for the body element (more than one occurrence is allowed)


CookieParam

The possible parameters of a cookie.

Constructors:

CookieExpire :: ClockTime -> CookieParam

CookieDomain :: String -> CookieParam

CookiePath :: String -> CookieParam

CookieSecure :: CookieParam


HtmlPage

The data type for representing HTML pages. The constructor arguments are the title, the parameters, and the contents (body) of the web page.

Constructors:

HtmlPage :: String -> [PageParam] -> [HtmlExp] -> HtmlPage


PageParam

The possible parameters of an HTML page.

Constructors:

PageEnc :: String -> PageParam

PageEnc : the encoding scheme of this page

PageCSS :: String -> PageParam

PageCSS s : a URL for a CSS file for this page

PageJScript :: String -> PageParam

PageJScript s : a URL for a Javascript file for this page

PageMeta :: [(String,String)] -> PageParam

PageMeta as : meta information (in form of attributes) for this page

PageLink :: [(String,String)] -> PageParam

PageLink as : link information (in form of attributes) for this page

PageBodyAttr :: (String,String) -> PageParam

PageBodyAttr attr : optional attribute for the body element of the page (more than one occurrence is allowed)


Exported operations:

defaultEncoding :: String   

The default encoding used in generated web pages.

Further infos:
  • solution complete, i.e., able to compute all solutions

idOfCgiRef :: CgiRef -> String   

Internal identifier of a CgiRef (intended only for internal use in other libraries!).

Further infos:
  • solution complete, i.e., able to compute all solutions

formEnc :: String -> FormParam   

An encoding scheme for a HTML form.

Further infos:
  • solution complete, i.e., able to compute all solutions

formCSS :: String -> FormParam   

A URL for a CSS file for a HTML form.

Further infos:
  • solution complete, i.e., able to compute all solutions

formMetaInfo :: [(String,String)] -> FormParam   

Meta information for a HTML form. The argument is a list of attributes included in the meta-tag in the header for this form.

Further infos:
  • solution complete, i.e., able to compute all solutions

formBodyAttr :: (String,String) -> FormParam   

Optional attribute for the body element of the HTML form. More than one occurrence is allowed, i.e., all such attributes are collected.

Further infos:
  • solution complete, i.e., able to compute all solutions

form :: String -> [HtmlExp] -> HtmlForm   

A basic HTML form for active web pages with the default encoding and a default background.

Example call: (form title hexps)

Parameters:
title : the title of the form
hexps : the form's body (list of HTML expressions)
Returns:
an HTML form
Further infos:
  • solution complete, i.e., able to compute all solutions

standardForm :: String -> [HtmlExp] -> HtmlForm   

A standard HTML form for active web pages where the title is included in the body as the first header.

Example call: (standardForm title hexps)

Parameters:
title : the title of the form
hexps : the form's body (list of HTML expressions)
Returns:
an HTML form with the title as the first header

cookieForm :: String -> [(String,String)] -> [HtmlExp] -> HtmlForm   

An HTML form with simple cookies. The cookies are sent to the client's browser together with this form.

Example call: (cookieForm title cookies hexps)

Parameters:
title : the title of the form
cookies : the cookies as a list of name/value pairs
hexps : the form's body (list of HTML expressions)
Returns:
an HTML form

addCookies :: [(String,String)] -> HtmlForm -> HtmlForm   

Add simple cookie to HTML form. The cookies are sent to the client's browser together with this form.

Example call: (addCookies cs form)

Parameters:
cs : the cookies as a list of name/value pairs
form : the form to add cookies to
Returns:
a new HTML form

answerText :: String -> HtmlForm   

A textual result instead of an HTML form as a result for active web pages.

Example call: (answerText txt)

Parameters:
txt : the contents of the result page
Returns:
an HTML answer form
Further infos:
  • solution complete, i.e., able to compute all solutions

answerEncText :: String -> String -> HtmlForm   

A textual result instead of an HTML form as a result for active web pages where the encoding is given as the first parameter.

Example call: (answerEncText enc txt)

Parameters:
enc : the encoding of the text(e.g., "utf-8" or "iso-8859-1")
txt : the contents of the result page
Returns:
an HTML answer form
Further infos:
  • solution complete, i.e., able to compute all solutions

addFormParam :: HtmlForm -> FormParam -> HtmlForm   

Adds a parameter to an HTML form.

Example call: (addFormParam form param)

Parameters:
form : a form
param : a form's parameter
Returns:
an HTML form
Further infos:
  • defined as left-associative infix operator with precedence 0
  • solution complete, i.e., able to compute all solutions

redirect :: Int -> String -> HtmlForm -> HtmlForm   

Adds redirection to given HTML form.

Example call: (redirect secs url form)

Parameters:
secs : Number of seconds to wait before executing autromatic redirection
url : The URL whereto redirect to
form : The form to add the header information to

expires :: Int -> HtmlForm -> HtmlForm   

Adds expire time to given HTML form.

Example call: (expires secs form)

Parameters:
secs : Number of seconds before document expires
form : The form to add the header information to

addSound :: String -> Bool -> HtmlForm -> HtmlForm   

Adds sound to given HTML form. The functions adds two different declarations for sound, one invented by Microsoft for the internet explorer, one introduced for netscape. As neither is an official part of HTML, addsound might not work on all systems and browsers. The greatest chance is by using sound files in MID-format.

Example call: (addSound soundfile loop form)

Parameters:
soundfile : Name of file containing the sound to be played
loop : Should sound go on infinitely? Use with care.
form : The form to add sound to

pageEnc :: String -> PageParam   

An encoding scheme for a HTML page.

Further infos:
  • solution complete, i.e., able to compute all solutions

pageCSS :: String -> PageParam   

A URL for a CSS file for a HTML page.

Further infos:
  • solution complete, i.e., able to compute all solutions

pageMetaInfo :: [(String,String)] -> PageParam   

Meta information for a HTML page. The argument is a list of attributes included in the meta-tag in the header for this page.

Further infos:
  • solution complete, i.e., able to compute all solutions

pageLinkInfo :: [(String,String)] -> PageParam   

Link information for a HTML page. The argument is a list of attributes included in the link-tag in the header for this page.

Further infos:
  • solution complete, i.e., able to compute all solutions

pageBodyAttr :: (String,String) -> PageParam   

Optional attribute for the body element of the web page. More than one occurrence is allowed, i.e., all such attributes are collected.

Further infos:
  • solution complete, i.e., able to compute all solutions

page :: String -> [HtmlExp] -> HtmlPage   

A basic HTML web page with the default encoding.

Example call: (page title hexps)

Parameters:
title : the title of the page
hexps : the page's body (list of HTML expressions)
Returns:
an HTML page
Further infos:
  • solution complete, i.e., able to compute all solutions

standardPage :: String -> [HtmlExp] -> HtmlPage   

A standard HTML web page where the title is included in the body as the first header.

Example call: (standardPage title hexps)

Parameters:
title : the title of the page
hexps : the page's body (list of HTML expressions)
Returns:
an HTML page with the title as the first header

addPageParam :: HtmlPage -> PageParam -> HtmlPage   

Adds a parameter to an HTML page.

Example call: (addPageParam form param)

Parameters:
form : a page
param : a page's parameter
Returns:
an HTML page
Further infos:
  • defined as left-associative infix operator with precedence 0
  • solution complete, i.e., able to compute all solutions

htxt :: String -> HtmlExp   

Basic text as HTML expression. The text may contain special HTML chars (like <,>,&,") which will be quoted so that they appear as in the parameter string.

htxts :: [String] -> [HtmlExp]   

A list of strings represented as a list of HTML expressions. The strings may contain special HTML chars that will be quoted.

hempty :: HtmlExp   

An empty HTML expression.

Further infos:
  • solution complete, i.e., able to compute all solutions

nbsp :: HtmlExp   

Non breaking Space

Further infos:
  • solution complete, i.e., able to compute all solutions

h1 :: [HtmlExp] -> HtmlExp   

Header 1

Further infos:
  • solution complete, i.e., able to compute all solutions

h2 :: [HtmlExp] -> HtmlExp   

Header 2

Further infos:
  • solution complete, i.e., able to compute all solutions

h3 :: [HtmlExp] -> HtmlExp   

Header 3

Further infos:
  • solution complete, i.e., able to compute all solutions

h4 :: [HtmlExp] -> HtmlExp   

Header 4

Further infos:
  • solution complete, i.e., able to compute all solutions

h5 :: [HtmlExp] -> HtmlExp   

Header 5

Further infos:
  • solution complete, i.e., able to compute all solutions

par :: [HtmlExp] -> HtmlExp   

Paragraph

Further infos:
  • solution complete, i.e., able to compute all solutions

emphasize :: [HtmlExp] -> HtmlExp   

Emphasize

Further infos:
  • solution complete, i.e., able to compute all solutions

strong :: [HtmlExp] -> HtmlExp   

Strong (more emphasized) text.

Further infos:
  • solution complete, i.e., able to compute all solutions

bold :: [HtmlExp] -> HtmlExp   

Boldface

Further infos:
  • solution complete, i.e., able to compute all solutions

italic :: [HtmlExp] -> HtmlExp   

Italic

Further infos:
  • solution complete, i.e., able to compute all solutions

code :: [HtmlExp] -> HtmlExp   

Program code

Further infos:
  • solution complete, i.e., able to compute all solutions

center :: [HtmlExp] -> HtmlExp   

Centered text

Further infos:
  • solution complete, i.e., able to compute all solutions

blink :: [HtmlExp] -> HtmlExp   

Blinking text

Further infos:
  • solution complete, i.e., able to compute all solutions

teletype :: [HtmlExp] -> HtmlExp   

Teletype font

Further infos:
  • solution complete, i.e., able to compute all solutions

pre :: [HtmlExp] -> HtmlExp   

Unformatted input, i.e., keep spaces and line breaks and don't quote special characters.

Further infos:
  • solution complete, i.e., able to compute all solutions

verbatim :: String -> HtmlExp   

Verbatim (unformatted), special characters (<,>,&,") are quoted.

address :: [HtmlExp] -> HtmlExp   

Address

Further infos:
  • solution complete, i.e., able to compute all solutions

href :: String -> [HtmlExp] -> HtmlExp   

Hypertext reference

Further infos:
  • solution complete, i.e., able to compute all solutions

anchor :: String -> [HtmlExp] -> HtmlExp   

An anchored text with a hypertext reference inside a document.

Further infos:
  • solution complete, i.e., able to compute all solutions

ulist :: [[HtmlExp]] -> HtmlExp   

Unordered list

Example call: (ulist items)

Parameters:
items : the list items where each item is a list of HTML expressions

olist :: [[HtmlExp]] -> HtmlExp   

Ordered list

Example call: (olist items)

Parameters:
items : the list items where each item is a list of HTML expressions

litem :: [HtmlExp] -> HtmlExp   

A single list item (usually not explicitly used)

Further infos:
  • solution complete, i.e., able to compute all solutions

dlist :: [([HtmlExp],[HtmlExp])] -> HtmlExp   

Description list

Example call: (dlist items)

Parameters:
items : a list of (title/description) pairs (of HTML expressions)

table :: [[[HtmlExp]]] -> HtmlExp   

Table with a matrix of items where each item is a list of HTML expressions.

headedTable :: [[[HtmlExp]]] -> HtmlExp   

Similar to table but introduces header tags for the first row.

addHeadings :: HtmlExp -> [[HtmlExp]] -> HtmlExp   

Add a row of items (where each item is a list of HTML expressions) as headings to a table. If the first argument is not a table, the headings are ignored.

hrule :: HtmlExp   

Horizontal rule

Further infos:
  • solution complete, i.e., able to compute all solutions

breakline :: HtmlExp   

Break a line

Further infos:
  • solution complete, i.e., able to compute all solutions

image :: String -> String -> HtmlExp   

Image

Example call: (image src alt)

Parameters:
src : the URL of the image
alt : the alternative text shown instead of the image

styleSheet :: String -> HtmlExp   

Defines a style sheet to be used in this HTML document.

Example call: (styleSheet css)

Parameters:
css : a string in CSS format
Further infos:
  • solution complete, i.e., able to compute all solutions

style :: String -> [HtmlExp] -> HtmlExp   

Provides a style for HTML elements. The style argument is the name of a style class defined in a style definition (see styleSheet) or in an external style sheet (see form and page parameters FormCSS and PageCSS).

Example call: (style st hexps)

Parameters:
st : name of a style class
hexps : list of HTML expressions
Further infos:
  • solution complete, i.e., able to compute all solutions

textstyle :: String -> String -> HtmlExp   

Provides a style for a basic text. The style argument is the name of a style class defined in an external style sheet.

Example call: (textstyle st txt)

Parameters:
st : name of a style class
txt : a string (special characters will be quoted)

blockstyle :: String -> [HtmlExp] -> HtmlExp   

Provides a style for a block of HTML elements. The style argument is the name of a style class defined in an external style sheet. This element is used (in contrast to "style") for larger blocks of HTML elements since a line break is placed before and after these elements.

Example call: (blockstyle st hexps)

Parameters:
st : name of a style class
hexps : list of HTML expressions
Further infos:
  • solution complete, i.e., able to compute all solutions

inline :: [HtmlExp] -> HtmlExp   

Joins a list of HTML elements into a single HTML element. Although this construction has no rendering, it is sometimes useful for programming when several HTML elements must be put together.

Example call: (inline hexps)

Parameters:
hexps : list of HTML expressions
Further infos:
  • solution complete, i.e., able to compute all solutions

block :: [HtmlExp] -> HtmlExp   

Joins a list of HTML elements into a block. A line break is placed before and after these elements.

Example call: (block hexps)

Parameters:
hexps : list of HTML expressions
Further infos:
  • solution complete, i.e., able to compute all solutions

button :: String -> ((CgiRef -> String) -> IO HtmlForm) -> HtmlExp   

Submit button with a label string and an event handler

resetbutton :: String -> HtmlExp   

Reset button with a label string

imageButton :: String -> ((CgiRef -> String) -> IO HtmlForm) -> HtmlExp   

Submit button in form of an imag.

Example call: (imageButton src handler)

Parameters:
src : url of the image
handler : event handler
Further infos:
  • solution complete, i.e., able to compute all solutions

textfield :: CgiRef -> String -> HtmlExp   

Input text field with a reference and an initial contents

password :: CgiRef -> HtmlExp   

Input text field (where the entered text is obscured) with a reference

textarea :: CgiRef -> (Int,Int) -> String -> HtmlExp   

Input text area with a reference, height/width, and initial contents

checkbox :: CgiRef -> String -> HtmlExp   

A checkbox with a reference and a value. The value is returned if checkbox is on, otherwise "" is returned.

checkedbox :: CgiRef -> String -> HtmlExp   

A checkbox that is initially checked with a reference and a value. The value is returned if checkbox is on, otherwise "" is returned.

radio_main :: CgiRef -> String -> HtmlExp   

A main button of a radio (initially "on") with a reference and a value. The value is returned of this button is on. A complete radio button suite always consists of a main button (radiomain) and some further buttons (radioothers) with the same reference. Initially, the main button is selected (or nothing is selected if one uses radiomainoff instead of radio_main). The user can select another button but always at most one button of the radio can be selected. The value corresponding to the selected button is returned in the environment for this radio reference.

radio_main_off :: CgiRef -> String -> HtmlExp   

A main button of a radio (initially "off") with a reference and a value. The value is returned of this button is on.

radio_other :: CgiRef -> String -> HtmlExp   

A further button of a radio (initially "off") with a reference (identical to the main button of this radio) and a value. The value is returned of this button is on.

selection :: CgiRef -> [(String,String)] -> HtmlExp   

A selection button with a reference and a list of name/value pairs. The names are shown in the selection and the value is returned for the selected name.

selectionInitial :: CgiRef -> [(String,String)] -> Int -> HtmlExp   

A selection button with a reference, a list of name/value pairs, and a preselected item in this list. The names are shown in the selection and the value is returned for the selected name.

Example call: (selectionInitial ref nvs sel)

Parameters:
ref : a CGI reference
nvs : list of name/value pairs
sel : the index of the initially selected item in the list nvs
Returns:
an HTML expression representing the selection button

multipleSelection :: CgiRef -> [(String,String,Bool)] -> HtmlExp   

A selection button with a reference and a list of name/value/flag pairs. The names are shown in the selection and the value is returned if the corresponding name is selected. If flag is True, the corresonding name is initially selected. If more than one name has been selected, all values are returned in one string where the values are separated by newline (\n) characters.

hiddenfield :: String -> String -> HtmlExp   

A hidden field to pass a value referenced by a fixed name. This function should be used with care since it may cause conflicts with the CGI-based implementation of this library.

Further infos:
  • solution complete, i.e., able to compute all solutions

htmlQuote :: String -> String   

Quotes special characters (<,>,&,", umlauts) in a string as HTML special characters.

htmlIsoUmlauts :: String -> String   

Translates umlauts in iso-8859-1 encoding into HTML special characters.

addAttr :: HtmlExp -> (String,String) -> HtmlExp   

Adds an attribute (name/value pair) to an HTML element.

Further infos:
  • defined as left-associative infix operator with precedence 0
  • solution complete, i.e., able to compute all solutions

addAttrs :: HtmlExp -> [(String,String)] -> HtmlExp   

Adds a list of attributes (name/value pair) to an HTML element.

Further infos:
  • defined as left-associative infix operator with precedence 0
  • solution complete, i.e., able to compute all solutions

addClass :: HtmlExp -> String -> HtmlExp   

Adds a class attribute to an HTML element.

Further infos:
  • defined as left-associative infix operator with precedence 0
  • solution complete, i.e., able to compute all solutions

showHtmlExps :: [HtmlExp] -> String   

Transforms a list of HTML expressions into string representation.

showHtmlExp :: HtmlExp -> String   

Transforms a single HTML expression into string representation.

showHtmlPage :: HtmlPage -> String   

Transforms HTML page into string representation.

Example call: (showHtmlPage page)

Parameters:
page : the HTML page
Returns:
string representation of the HTML document

getUrlParameter :: IO String   

Gets the parameter attached to the URL of the script. For instance, if the script is called with URL "http://.../script.cgi?parameter", then "parameter" is returned by this I/O action. Note that an URL parameter should be "URL encoded" to avoid the appearance of characters with a special meaning. Use the functions "urlencoded2string" and "string2urlencoded" to decode and encode such parameters, respectively.

urlencoded2string :: String -> String   

Translates urlencoded string into equivalent ASCII string.

string2urlencoded :: String -> String   

Translates arbitrary strings into equivalent urlencoded string.

getCookies :: IO [(String,String)]   

Gets the cookies sent from the browser for the current CGI script. The cookies are represented in the form of name/value pairs since no other components are important here.

coordinates :: (CgiRef -> String) -> Maybe (Int,Int)   

For image buttons: retrieve the coordinates where the user clicked within the image.

runFormServerWithKey :: String -> String -> IO HtmlForm -> IO ()   

The server implementing an HTML form (possibly containing input fields). It receives a message containing the environment of the client's web browser, translates the HTML form w.r.t. this environment into a string representation of the complete HTML document and sends the string representation back to the client's browser by binding the corresponding message argument.

Example call: (runFormServerWithKey url cgikey hformact)

Parameters:
url : the URL of this executable.
cgikey : a unique key to identify this CGI script (used for safe storing of event handlers in this server)
hformact : an IO action returning an HTML form

runFormServerWithKeyAndFormParams :: String -> String -> [FormParam] -> IO HtmlForm -> IO ()   

The server implementing an HTML form (possibly containing input fields). It receives a message containing the environment of the client's web browser, translates the HTML form w.r.t. this environment into a string representation of the complete HTML document and sends the string representation back to the client's browser by binding the corresponding message argument.

Example call: (runFormServerWithKeyAndFormParams url cgikey formparams hformact)

Parameters:
url : the URL of this executable.
cgikey : a unique key to identify this CGI script (used for safe storing of event handlers on the web server)
formparams : form parameters added to the initial and all subsequent forms
hformact : an IO action returning an HTML form

showLatexExps :: [HtmlExp] -> String   

Transforms HTML expressions into LaTeX string representation.

showLatexExp :: HtmlExp -> String   

Transforms an HTML expression into LaTeX string representation.

Further infos:
  • partially defined

htmlSpecialChars2tex :: String -> String   

Convert special HTML characters into their LaTeX representation, if necessary.

showLatexDoc :: [HtmlExp] -> String   

Transforms HTML expressions into a string representation of a complete LaTeX document.

showLatexDocWithPackages :: [HtmlExp] -> [String] -> String   

Transforms HTML expressions into a string representation of a complete LaTeX document. The variable "packages" holds the packages to add to the latex document e.g. "ngerman"

showLatexDocs :: [[HtmlExp]] -> String   

Transforms a list of HTML expressions into a string representation of a complete LaTeX document where each list entry appears on a separate page.

showLatexDocsWithPackages :: [[HtmlExp]] -> [String] -> String   

Transforms a list of HTML expressions into a string representation of a complete LaTeX document where each list entry appears on a separate page. The variable "packages" holds the packages to add to the latex document (e.g., "ngerman").

germanLatexDoc :: [HtmlExp] -> String   

show german latex document

intForm :: IO HtmlForm -> IO ()   

Execute an HTML form in "interactive" mode.

intFormMain :: String -> String -> String -> String -> Bool -> String -> IO HtmlForm -> IO ()   

Execute an HTML form in "interactive" mode with various parameters.

Example call: (intFormMain baseurl basecgi reldir cginame forever urlparam hformact)

Parameters:
baseurl : the base URL where this script is accessible for clients
basecgi : the base directory in the local file system where this script should stored for execution
reldir : the relative path added to baseurl and basecgi
cginame : the name of the executable cgi script
forever : True if the interactive execution should not be terminated when the final web page (without a handler) is shown
urlparam : the URL parameter for the initial call to the cgi script
hformact : IO action returning the HTML form