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 2013
defaultEncoding
:: String
The default encoding used in generated web pages. |
defaultBackground
:: (String,String)
The default background for 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. |
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. |
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 anchor for 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. |
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
The type of event handlers in HTML forms.
Type synonym: HtmlHandler = (CgiRef -> String) -> IO HtmlForm
The (abstract) data type for representing references to input elements in HTML forms.
Constructors:
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)
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
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
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)
The possible parameters of a cookie.
Constructors:
CookieExpire
:: ClockTime -> CookieParam
CookieDomain
:: String -> CookieParam
CookiePath
:: String -> CookieParam
CookieSecure
:: CookieParam
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
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
|
The default encoding used in generated web pages.
|
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The default background for generated web pages.
|
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Internal identifier of a CgiRef (intended only for internal use in other libraries!).
|
|
An encoding scheme for a HTML form.
|
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A URL for a CSS file for a HTML form.
|
|
A basic HTML form for active web pages with the default encoding and a default background.
Example call:
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A standard HTML form for active web pages where the title is included in the body as the first header.
Example call:
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|
An HTML form with simple cookies. The cookies are sent to the client's browser together with this form.
Example call:
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Add simple cookie to HTML form. The cookies are sent to the client's browser together with this form.
Example call:
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A textual result instead of an HTML form as a result for active web pages.
Example call:
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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:
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Adds a parameter to an HTML form.
Example call:
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Adds redirection to given HTML form.
Example call:
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Adds expire time to given HTML form.
Example call:
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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:
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An encoding scheme for a HTML page.
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A URL for a CSS file for a HTML page.
|
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Meta information for a HTML page. The argument is a list of
attributes included in the
|
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Link information for a HTML page. The argument is a list of
attributes included in the
|
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A basic HTML web page with the default encoding.
Example call:
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|
A standard HTML web page where the title is included in the body as the first header.
Example call:
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Adds a parameter to an HTML page.
Example call:
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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. |
|
A list of strings represented as a list of HTML expressions. The strings may contain special HTML chars that will be quoted. |
|
An empty HTML expression.
|
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Non breaking Space
|
|
Header 1
|
|
Header 2
|
|
Header 3
|
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Header 4
|
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Header 5
|
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Paragraph
|
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Emphasize
|
|
Strong (more emphasized) text.
|
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Boldface
|
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Italic
|
|
Program code
|
|
Centered text
|
|
Blinking text
|
|
Teletype font
|
|
Unformatted input, i.e., keep spaces and line breaks and don't quote special characters.
|
|
Verbatim (unformatted), special characters (<,>,&,") are quoted. |
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Address
|
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Hypertext reference
|
|
An anchor for hypertext reference inside a document
|
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Unordered list
Example call:
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Ordered list
Example call:
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A single list item (usually not explicitly used)
|
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Description list
Example call:
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Table with a matrix of items where each item is a list of HTML expressions. |
|
Similar to |
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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. |
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Horizontal rule
|
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Break a line
|
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Image
Example call:
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Defines a style sheet to be used in this HTML document.
Example call:
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Provides a style for HTML elements.
The style argument is the name of a style class defined in a
style definition (see
Example call:
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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:
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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:
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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:
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Joins a list of HTML elements into a block. A line break is placed before and after these elements.
Example call:
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Submit button with a label string and an event handler |
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Reset button with a label string |
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Submit button in form of an imag.
Example call:
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Input text field with a reference and an initial contents |
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Input text field (where the entered text is obscured) with a reference |
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Input text area with a reference, height/width, and initial contents |
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A checkbox with a reference and a value. The value is returned if checkbox is on, otherwise "" is returned. |
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A checkbox that is initially checked with a reference and a value. The value is returned if checkbox is on, otherwise "" is returned. |
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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. |
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A main button of a radio (initially "off") with a reference and a value. The value is returned of this button is on. |
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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. |
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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. |
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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:
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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 ( |
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Quotes special characters (
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Translates umlauts in iso-8859-1 encoding into HTML special characters. |
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Adds an attribute (name/value pair) to an HTML element.
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Adds a list of attributes (name/value pair) to an HTML element.
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Adds a class attribute to an HTML element.
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Transforms a list of HTML expressions into string representation. |
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Transforms a single HTML expression into string representation. |
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Transforms HTML page into string representation.
Example call:
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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. |
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Translates urlencoded string into equivalent ASCII string.
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Translates arbitrary strings into equivalent urlencoded string.
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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. |
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For image buttons: retrieve the coordinates where the user clicked within the image. |
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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:
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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:
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Transforms HTML expressions into LaTeX string representation. |
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Transforms an HTML expression into LaTeX string representation.
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Convert special HTML characters into their LaTeX representation, if necessary.
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Transforms HTML expressions into a string representation of a complete LaTeX document. |
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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" |
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Transforms a list of HTML expressions into a string representation of a complete LaTeX document where each list entry appears on a separate page. |
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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"). |
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show german latex document |
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Execute an HTML form in "interactive" mode. |
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Execute an HTML form in "interactive" mode with various parameters.
Example call:
|