[comment {-*- tcl -*- doctools manpage}]
[vset HTML_VERSION 1.6]
[manpage_begin html n [vset HTML_VERSION]]
[see_also htmlparse]
[see_also ncgi]
[keywords checkbox]
[keywords checkbutton]
[keywords form]
[keywords html]
[keywords radiobutton]
[keywords table]
[moddesc   {HTML Generation}]
[titledesc {Procedures to generate HTML structures}]
[category  {CGI programming}]
[require Tcl "8.5 9"]
[require html [opt [vset HTML_VERSION]]]
[description]
[para]

The package [package html] provides commands that generate HTML.
These commands typically return an HTML string as their result. In
particular, they do not output their result to [const stdout].

[para]

The command [cmd ::html::init] should be called early to initialize
the module.  You can also use this procedure to define default values
for HTML tag parameters.

[list_begin definitions]

[call [cmd ::html::author] [arg author]]

[emph {Side effect only}].  Call this before [cmd ::html::head] to
define an author for the page.  The author is noted in a comment in
the HEAD section.

[call [cmd ::html::bodyTag] [arg args]]

Generate a [term body] tag.  The tag parameters are taken from [arg args] or
from the body.* attributes define with [cmd ::html::init].

[call [cmd ::html::cell] [arg {param value}] [opt [arg tag]]]

Generate a [term td] (or [term th]) tag, a value, and a closing
[term td] (or [term th]) tag. The
tag parameters come from [arg param] or TD.* attributes defined with
[cmd ::html::init].  This uses [cmd ::html::font] to insert a standard
[term font] tag into the table cell. The [arg tag] argument defaults to "td".

[call [cmd ::html::checkbox] [arg {name value}]]

Generate a [term checkbox] form element with the specified name and value.
This uses [cmd ::html::checkValue].

[call [cmd ::html::checkSet] [arg {key sep list}]]

Generate a set of [term checkbox] form elements and associated labels.  The
[arg list] should contain an alternating list of labels and values.
This uses [cmd ::html::checkbox]. All the [term checkbox] buttons share the
same [arg key] for their name. The [arg sep] is text used to separate
the elements.

[call [cmd ::html::checkValue] [arg name] [opt [arg value]]]

Generate the "name=[arg name] value=[arg value]" for a [term checkbox] form
element.  If the CGI variable [arg name] has the value [arg value],
then SELECTED is added to the return value. [arg value] defaults to
"1".

[call [cmd ::html::closeTag]]

Pop a tag off the stack created by [cmd ::html::openTag] and generate
the corresponding close tag (e.g., </body>).

[call [cmd ::html::default] [arg key] [opt [arg param]]]

This procedure is used by [cmd ::html::tagParam] to generate the name,
value list of parameters for a tag.  The [cmd ::html::default]
procedure is used to generate default values for those items not
already in [arg param].  If the value identified by [arg key] matches
a value in [arg param] then this procedure returns the empty string.
Otherwise, it returns a "parameter=value" string for a form element
identified by [arg key].  The [arg key] has the form "tag.parameter"
(e.g., body.bgcolor).  Use [cmd ::html::init] to register default
values. [arg param] defaults to the empty string.

[call [cmd ::html::description] [arg description]]

[emph {Side effect only}].  Call this before [cmd ::html::head] to
define a description [term meta] tag for the page.  This tag is generated
later in the call to [cmd ::html::head].

[call [cmd ::html::end]]

Pop all open tags from the stack and generate the corresponding close
HTML tags, (e.g., </body></html>).

[call [cmd ::html::eval] [arg arg] [opt [arg args]]]

This procedure is similar to the built-in Tcl [cmd eval] command.  The
only difference is that it returns "" so it can be called from an HTML
template file without appending unwanted results.

[call [cmd ::html::extractParam] [arg {param key}] [opt [arg varName]]]

This is a parsing procedure that extracts the value of [arg key] from
[arg param], which is a HTML-style "name=quotedvalue" list.

[arg varName] is used as the name of a Tcl variable that is changed to
have the value found in the parameters.  The function returns 1 if the
parameter was found in [arg param], otherwise it returns 0.  If the
[arg varName] is not specified, then [arg key] is used as the variable
name.

[call [cmd ::html::font] [arg args]]

Generate a standard [term font] tag.  The parameters to the tag are taken
from [arg args] and the HTML defaults defined with [cmd ::html::init].

[call [cmd ::html::for] [arg {start test next body}]]

This procedure is similar to the built-in Tcl [cmd for] control
structure.  Rather than evaluating the body, it returns the subst'ed
[arg body]. Each iteration of the loop causes another string to be
concatenated to the result value.

[call [cmd ::html::foreach] [arg {varlist1 list1}] [opt [arg {varlist2 list2 ...}]] [arg body]]

This procedure is similar to the built-in Tcl [cmd foreach] control
structure.  Rather than evaluating the body, it returns the subst'ed
[arg body].  Each iteration of the loop causes another string to be
concatenated to the result value.

[call [cmd ::html::formValue] [arg name] [opt [arg defvalue]]]

Return a name and value pair, where the value is initialized from
existing CGI data, if any.  The result has this form:

[para]
[example {
  name="fred" value="freds value"
}]

[call [cmd ::html::getFormInfo] [arg args]]

Generate hidden fields to capture form values.  If [arg args] is
empty, then hidden fields are generated for all CGI values.  Otherwise
args is a list of string match patterns for form element names.

[call [cmd ::html::getTitle]]

Return the title string, with out the surrounding [term title] tag,
set with a previous call to [cmd ::html::title].

[call [cmd ::html::h] [arg {level string}] [opt [arg param]]]

Generate a heading (e.g., [term h[var level]]) tag.  The [arg string] is nested in the
heading, and [arg param] is used for the tag parameters.

[call [cmd ::html::h1] [arg string] [opt [arg param]]]

Generate an [term h1] tag.  See [cmd ::html::h].

[call [cmd ::html::h2] [arg string] [opt [arg param]]]

Generate an [term h2] tag.  See [cmd ::html::h].

[call [cmd ::html::h3] [arg string] [opt [arg param]]]

Generate an [term h3] tag.  See [cmd ::html::h].

[call [cmd ::html::h4] [arg string] [opt [arg param]]]

Generate an [term h4] tag.  See [cmd ::html::h].

[call [cmd ::html::h5] [arg string] [opt [arg param]]]

Generate an [term h5] tag.  See [cmd ::html::h].

[call [cmd ::html::h6] [arg string] [opt [arg param]]]

Generate an [term h6] tag.  See [cmd ::html::h].

[call [cmd ::html::hdrRow] [arg args]]

Generate a table row, including [term tr] and [term th] tags.
Each value in [arg args] is place into its own table cell.
This uses [cmd ::html::cell].

[call [cmd ::html::head] [arg title]]

Generate the [term head] section that includes the page [term title].
If previous calls have been made to
[cmd ::html::author],
[cmd ::html::keywords],
[cmd ::html::description],
or
[cmd ::html::meta]
then additional tags are inserted into the [term head] section.
This leaves an open [term html] tag pushed on the stack with
[cmd ::html::openTag].

[call [cmd ::html::headTag] [arg string]]

Save a tag for inclusion in the [term head] section generated by

[cmd ::html::head].  The [arg string] is everything in the tag except
the enclosing angle brackets, < >.

[call [cmd ::html::html_entities] [arg string]]

This command replaces all special characters in the [arg string] with
their HTML entities and returns the modified text.

[call [cmd ::html::if] [arg {expr1 body1}] [opt "[const elseif] [arg {expr2 body2 ...}]"] [opt "[const else] [arg bodyN]"]]

This procedure is similar to the built-in Tcl [cmd if] control
structure.  Rather than evaluating the body of the branch that is
taken, it returns the subst'ed [arg body].  Note that the syntax is
slightly more restrictive than that of the built-in Tcl [cmd if]
control structure.

[call [cmd ::html::init] [opt [arg list]]]

[cmd ::html::init] accepts a Tcl-style name-value list that defines
values for items with a name of the form "tag.parameter".  For
example, a default with key "body.bgcolor" defines the background
color for the [term body] tag.

[call [cmd ::html::keywords] [arg args]]

[emph {Side effect only}].  Call this before [cmd ::html::head] to
define a keyword [term meta] tag for the page.  The [term meta] tag
is included in the result of [cmd ::html::head].

[call [cmd ::html::mailto] [arg email] [opt [arg subject]]]

Generate a hypertext link to a mailto: URL.

[call [cmd ::html::meta] [arg args]]

Compatibility name for [cmd html::meta_name].

[call [cmd ::html::meta_name] [arg args]]

[emph {Side effect only}].

Call this before [cmd ::html::head] to define a [term meta] tag for
the page.

The arguments ([arg args]) are a Tcl-style name, value list that is
used for the [const name=] and [const content=] attributes of the
[term meta] tag.  The [term meta] tag is included in the result of
[cmd ::html::head].


[call [cmd ::html::meta_equiv] [arg args]]

[emph {Side effect only}].

Call this before [cmd ::html::head] to define a [term meta] tag for
the page.

The arguments ([arg args]) are a Tcl-style name, value list that is
used for the [const http-equiv=] and [const content=] attributes of
the [term meta] tag.  The [term meta] tag is included in the result of
[cmd ::html::head].

[call [cmd ::html::meta_charset] [arg charset]]

[emph {Side effect only}].

Call this before [cmd ::html::head] to
define a [term meta] tag for the page.

The [arg charset] is used with the [const charset=] attribute of the
[term meta] tag.  The [term meta] tag is included in the result of
[cmd ::html::head].

[call [cmd ::html::css] [arg href]]

[emph {Side effect only}].  Call this before [cmd ::html::head] to
define a [term link] tag for a linked CSS document.  The [arg href] 
value is a HTTP URL to a CSS document. The [term link] tag is included 
in the result of [cmd ::html::head].

[para]

Multiple calls of this command are allowed, enabling the use of
multiple CSS document references. In other words, the arguments
of multiple calls are accumulated, and do not overwrite each other.

[call [cmd ::html::css-clear]]

[emph {Side effect only}].  Call this before [cmd ::html::head] to
clear all links to CSS documents.
[para]

Multiple calls of this command are allowed, doing nothing after the
first of a sequence with no intervening [cmd ::html::css].

[call [cmd ::html::js] [arg href]]

[emph {Side effect only}].  Call this before [cmd ::html::head] to
define a [term script] tag for a linked JavaScript document.  The 
[arg href] is a HTTP URL to a JavaScript document. The [term script]
tag is included in the result of [cmd ::html::head].

[para]

Multiple calls of this command are allowed, enabling the use of
multiple JavaScript document references. In other words, the arguments
of multiple calls are accumulated, and do not overwrite each other.


[call [cmd ::html::js-clear]]

[emph {Side effect only}].  Call this before [cmd ::html::head] to
clear all links to JavaScript documents.
[para]

Multiple calls of this command are allowed, doing nothing after the
first of a sequence with no intervening [cmd ::html::js].

[call [cmd ::html::minorList] [arg list] [opt [arg ordered]]]

Generate an ordered or unordered list of links.  The [arg list] is a
Tcl-style name, value list of labels and urls for the links.

[arg ordered] is a boolean used to choose between an ordered or
unordered list. It defaults to [const false].

[call [cmd ::html::minorMenu] [arg list] [opt [arg sep]]]

Generate a series of hypertext links.  The [arg list] is a Tcl-style
name, value list of labels and urls for the links.  The [arg sep] is
the text to put between each link. It defaults to " | ".

[call [cmd ::html::nl2br] [arg string]]

This command replaces all line-endings in the [arg string] with a
[term br] tag and returns the modified text.

[call [cmd ::html::openTag] [arg tag] [opt [arg param]]]

Push [arg tag] onto a stack and generate the opening tag for
[arg tag]. Use [cmd ::html::closeTag] to pop the tag from the
stack. The second argument provides any tag arguments, as a
list whose elements are formatted to be in the form
"[var key]=[const value]".

[call [cmd ::html::paramRow] [arg list] [opt [arg rparam]] [opt [arg cparam]]]

Generate a table row, including [term tr] and [term td] tags. Each value in

[arg list] is placed into its own table cell. This uses

[cmd ::html::cell]. The value of [arg rparam] is used as parameter for
the [term tr] tag. The value of [arg cparam] is passed to [cmd ::html::cell]
as parameter for the [term td] tags.

[call [cmd ::html::passwordInput] [opt [arg name]]]

Generate an [term input] tag of type [term password]. The [arg name] defaults to
"password".

[call [cmd ::html::passwordInputRow] [arg label] [opt [arg name]]]

Format a table row containing a label and an [term input] tag of type
[term password]. The [arg name] defaults to "password".

[call [cmd ::html::quoteFormValue] [arg value]]

Quote special characters in [arg value] by replacing them with HTML
entities for quotes, ampersand, and angle brackets.

[call [cmd ::html::radioSet] [arg {key sep list}]]

Generate a set of [term input] tags of type [term radio] and an associated text
label.  All the radio buttons share the same [arg key] for their name.
The [arg sep] is text used to separate the elements.  The [arg list]
is a Tcl-style label, value list.

[call [cmd ::html::radioValue] [arg {name value}]]

Generate the "name=[arg name] value=[arg value]" for a [term radio] form
element.  If the CGI variable [arg name] has the value [arg value],
then SELECTED is added to the return value.

[call [cmd ::html::refresh] [arg {seconds url}]]

Set up a refresh [term meta] tag. Call this before [cmd ::html::head] and the
HEAD section will contain a [term meta] tag that causes the document to
refresh in [arg seconds] seconds.  The [arg url] is optional.  If
specified, it specifies a new page to load after the refresh interval.

[call [cmd ::html::row] [arg args]]

Generate a table row, including [term tr] and [term td] tags.  Each value in
[arg args] is place into its own table cell. This uses
[cmd ::html::cell]. Ignores any default information set up via
[cmd ::html::init].

[call [cmd ::html::select] [arg {name param choices}] [opt [arg current]]]

Generate a [term select] form element and nested [term option] tags. The [arg name]
and [arg param] are used to generate the [term select] tag. The [arg choices]
list is a Tcl-style name, value list.

[call [cmd ::html::selectPlain] [arg {name param choices}] [opt [arg current]]]

Like [cmd ::html::select] except that [arg choices] is a Tcl list of
values used for the [term option] tags.  The label and the value for each
[term option] are the same.

[call [cmd ::html::set] [arg {var val}]]

This procedure is similar to the built-in Tcl [cmd set] command.  The
main difference is that it returns "" so it can be called from an HTML
template file without appending unwanted results.  The other
difference is that it must take two arguments.

[call [cmd ::html::submit] [arg label] [opt [arg name]] [opt [arg title]]]

Generate an [term input] tag of type [term submit].

The [arg name] defaults to "submit".

When a non-empty [arg title] string is specified the button gains a
[const title=] attribute with that value.

[call [cmd ::html::tableFromArray] [arg arrname] [opt [arg param]] [opt [arg pat]]]

Generate a two-column [term table] and nested rows to display a Tcl array. The
table gets a heading that matches the array name, and each generated row
contains a name, value pair. The array names are sorted ([cmd lsort] without
special options). The argument [arg param] is for the [term table] tag and has
to contain a pre-formatted string. The [arg pat] is a [cmd {string match}]
pattern used to select the array elements to show in the table. It defaults to
[const *], i.e. the whole array is shown.

[call [cmd ::html::tableFromList] [arg querylist] [opt [arg param]]]

Generate a two-column [term table] and nested rows to display [arg querylist],
which is a Tcl dictionary. Each generated row contains a name, value pair. The
information is shown in the same order as specified in the dictionary. The
argument [arg param] is for the [term table] tag  and has to contain a
pre-formatted string.

[call [cmd ::html::textarea] [arg name] [opt [arg param]] [opt [arg current]]]

Generate a [term textarea] tag wrapped around its current values.

[call [cmd ::html::textInput] [arg {name value args}]]

Generate an [term input] form tag with type [term text].  This uses

[cmd ::html::formValue].  The args is any additional tag attributes
you want to put into the [term input] tag.

[call [cmd ::html::textInputRow] [arg {label name value args}]]

Generate an [term input] form tag with type [term text] formatted into a table row
with an associated label.  The args is any additional tag attributes
you want to put into the [term input] tag.

[comment {
[call [cmd ::html::title] [arg title]]

[emph {Side effect only}].  Call this before [cmd ::html::head] to
define the [term title] for a page.
}]

[call [cmd ::html::varEmpty] [arg name]]

This returns 1 if the named variable either does not exist or has the
empty string for its value.

[call [cmd ::html::while] [arg {test body}]]

This procedure is similar to the built-in Tcl [cmd while] control
structure.  Rather than evaluating the body, it returns the subst'ed
[arg body].  Each iteration of the loop causes another string to be
concatenated to the result value.

[call [cmd ::html::doctype] [arg id]]

This procedure can be used to build the standard DOCTYPE
declaration string. It will return the standard declaration
string for the id, or throw an error if the id is not known.
The following id's are defined:

[list_begin enumerated]
[enum] HTML32
[enum] HTML40
[enum] HTML40T
[enum] HTML40F
[enum] HTML401
[enum] HTML401T
[enum] HTML401F
[enum] XHTML10S
[enum] XHTML10T
[enum] XHTML10F
[enum] XHTML11
[enum] XHTMLB
[list_end]

[call [cmd ::html::wrapTag] [arg tag] [opt [arg text]] [opt [arg args]]]

A helper to wrap a [arg text] in a pair of open/close [arg tag]s.

The arguments ([arg args]) are a Tcl-style name, value list that is
used to provide attributes and associated values to the opening tag.

The result is a string with the open [arg tag] along with the optional
attributes, the optional text, and the closed tag.

[list_end]

[vset CATEGORY html]
[include ../common-text/feedback.inc]
[manpage_end]
