| Tk::HyperText - An ROText widget which renders HTML code. |
Tk::HyperText - An ROText widget which renders HTML code.
use Tk::HyperText;
my $html = $mw->Scrolled ('HyperText',
-scrollbars => 'ose',
-wrap => 'word',
)->pack (-fill => 'both', -expand => 1);
$html->setHandler (Title => \&onNewTitle); $html->setHandler (Resource => \&onResource); $html->setHandler (Submit => \&onFormSubmit);
$html->loadString (qq~<html>
<head>
<title>Hello world!</title>
</head>
<body bgcolor="#0099FF">
<font size="6" family="Impact" color="#FFFFFF">
<strong>Hello, world!</strong>
</font>
</body>
</html>
~);
Tk::HyperText is a widget derived from Tk::ROText that renders HTML
code.
First of all, Tk::HyperText is NOT expected to become a full-fledged web browser widget. This module's original idea was just to be a simple HTML-rendering widget, specifically to match the capabilities of the AOL Instant Messenger's HTML widgets. That is, to render basic text formatting, images, and hyperlinks. Anything this module does that's extra is only there because I was up to the challenge.
This module is NOT backwards compatible with versions 0.05 and below.
Specifically, the module was rewritten to use HTML::TokeParser as its
HTML parsing engine instead of parsing it as plain text. Also, the methods
have all been changed. The old module's overloading of the standard
Tk::Text methods was causing all kinds of problems, and since this isn't
really a ``drop-in'' replacement for the other Text widgets, its methods don't
need to follow the same format.
Also, support for Cascading StyleSheets doesn't work at this time. It may be re-implemented at a later date, but, as this widget is not meant to become a full-fledged web browser (see PURPOSE), the CSS support might not return.
Run the `demo.pl` script included in the distribution.
-continue is an alias for -continuous if you're terrible at spelling.
-attributes. This data structure defines some
default styles for use within the rendered pages.
my $html = $mw->Scrolled('HyperText',
-attributes => {
-anchor => { # Hyperlink colors
-normal => '#0000FF', # or 'blue'
-hover => '#FF0000', # or 'red'
-active => '#FF0000', # or 'red'
-visited => '#990099', # or 'purple'
},
-font => {
-family => 'Times',
-mono => 'Courier',
-size => 'medium', # or any HTML size
# (1..6, xx-small..xx-large)
# Text styles, set them to 1 to apply the effect.
# I don't see why anyone would want to use these,
# but they're here anyway.
-bold => 0, # Bold
-italic => 0, # Italic
-under => 0, # Underline
-over => 0, # Overstrike
},
-style => {
-margins => 0, # Text margins
-color => '#000000', # Text color
-back => '#FFFFFF', # Text BG color
},
},
);
$html->setHandler (Title => sub {
my ($self,$newTitle) = @_;
$mw->configure (-title => $newTitle);
});
It will allow the following tags:
<html>, <head>, <title>, <body>, <a>, <p>, <br>, <hr>, <img>, <font>, <center>, <sup>, <sub>, <b>, <i>, <u>, <s>
All other tags are denied.
about:blank'' URI
in most modern web browsers).
All events receive a reference to its parent widget as $_[0].
The following are the event handlers currently supported by
Tk::HyperText:
<title>...</title> sequence is found
in the HTML code. $newTitle is the text of the new page title.
%info contains all
the information about the requested resource.
# For hyperlinks (<a> tags)
%info = (
tag => 'a', # The HTML tag.
href => 'http://google.com', # The <a href> attribute.
src => 'http://google.com', # src is an alias for href
target => '_blank', # The <a target> attribute
);
# For images (<img> tags)
%info = (
tag => 'img', # The HTML tag.
src => 'avatar.jpg', # The <img src> attribute.
width => 48, # The <img width> attribute.
height => 48, # The <img height> attribute.
vspace => '', # <img vspace>
hspace => '', # <img hspace>
align => '', # <img align>
alt => 'alt text', # <img alt>
);
Note about Images: The Resource event, when called for an image, wants
you to return the image's data, Base64-encoded. Otherwise, the image on the
page will show up as a ``broken image'' icon. Here is an example of how to
handle image resources:
use LWP::Simple; use MIME::Base64 qw(encode_base64);
$html->setHandler (Resource => sub {
my ($self,%info) = @_;
if ($info{tag} eq 'img') {
# If an http:// link, get the image from the web.
if ($info{src} =~ /^http/i) {
my $bin = get $info{src};
my $enc = encode_base64($bin);
return $enc;
}
# Otherwise, read it from a local file.
else {
if (-f $src) {
open (READ, $src);
binmode READ;
my @bin = <READ>;
close (READ);
chomp @bin;
my $enc = encode_base64(join("\n",@bin));
return enc;
}
}
}
return undef;
});
On hyperlink resources, the module doesn't need or expect any return value.
It should be up to the handler to do what it needs (i.e. fetch the source
of the page, blank out the HTML widget and then loadString the new code
into it).
%info is a
hash containing the information about the event.
%info = (
form => 'login', # The <form name> attribute.
action => '/login.cgi', # The <form action> attribute.
method => 'POST', # The <form method> attribute.
enctype => 'text/plain', # The <form enctype> attribute.
fields => { # Hashref of form names and values.
username => 'soandso',
password => 'bigsecret',
remember => 1,
},
);
The event doesn't want or expect a return value, similarly to the Resource
event for normal anchor tags. Your code should know what to do with this
event (i.e. get LWP::UserAgent to post the form to a remote web address,
stream the results of the request in through loadString, etc.)
The following tags and attributes are supported by this module:
<html>
<head>
<title>
<body> (bgcolor, text, link, alink, vlink)
<a> (href, target)
<br>
<p>
<form> (name, action, method, enctype)
<textarea> (name, cols, rows, disabled)
<select> (name, size, multiple)
<option> (value, selected)
<input> (name, type, size, value, maxlength, disabled, checked)
types: text, password, checkbox, radio, button, submit, reset
<table> (border, cellspacing, cellpadding)
<tr>
<td> (colspan, rowspan)
<th>
<thead>
<tbody>
<tfoot>
<hr> (height, size)
<img> (src, width, height, vspace, hspace, align, alt)*
<font> (face, size, color, back)
<basefont>
<h1>..<h6>
<ol> (type, start)
<ul> (type)
<li>
<blockquote>
<div> (align)
<span>
<pre>
<code>
<tt>
<kbd>
<samp>
<center>
<right>
<left>
<sup>
<sub>
<big>
<small>
<b>
<strong>
<i>
<em>
<address>
<var>
<cite>
<def>
<u>
<ins>
<s>
<del>
the Tk::ROText manpage and the Tk::Text manpage.
0.12 Feb 25, 2016 - Add more dependencies to get CPANTS to pass.
0.11 Feb 23, 2016 - Add dependency on HTML::TokeParser.
0.10 Sep 18, 2015 - Add dependency on Tk::Derived.
0.09 Nov 11, 2013 - Reformatted as per CPAN::Changes::Spec -neilbowers
0.08 Nov 1, 2013 - Use hex() instead of eval() to convert hex strings into numbers. - Set default values for body colors. - Stop demo.pl from being installed; rename it to eg/example.
0.06 July 14, 2008 - The module uses HTML::TokeParser now and does "real" HTML parsing. - Badly broke backwards compatibility.
0.05 July 11, 2007
- Added support for "tag permissions", so that you can allow/deny specific tags from
being rendered (i.e. say you're making a chat client which uses HTML and you don't
want people inserting images into their messages, or style sheets, etc)
- Added the tags <address>, <var>, <cite>, and <def>.
- Added the <hr> tag.
- Added two "default images" that are displayed when an <img> tag tries to show
an image that couldn't be found, or was found but is a file type that isn't
supported (e.g. <img src="index.html"> would show an "invalid image" icon).
- Bug fix: every opened tag that modifies your style will now copy all the other
stacks. As a result, opening <font back="yellow">, then <font color="red">, and
then closing the red font, will still apply the yellow background to the following
text. The same is true for every tag.
- Added some support for Cascading StyleSheets.
- Added some actual use for the "active link color": it's used as the hover color
on links (using it as a true active color is mostly useless, since most of the
time the page won't remain very long when clicking on a link to even see it)
0.04 June 23, 2007
- Added support for the <basefont> tag.
- Added support for <ul>, <ol>, and <li>. I've even extended the HTML specs a
little and added "diamonds" as a shape for <ul>, and allowed <ul> to specify
a decimal escape code (<ul type="#0164">)
- Added a "page history", so that the "visited link color" on pages can actually
be applied to the links.
- Fixed the <blockquote> so that the margin applies to the right side as well.
0.02 June 20, 2007
- Bugfix: on consecutive insert() commands (without clearing it in between),
the entire content of the HTML already in the widget would be inserted again,
in addition to the new content. This has been fixed.
0.01 June 20, 2007 - Initial release.
Noah Petherbridge, http://www.kirsle.net/
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.10.0 or, at your option, any later version of Perl 5 you may have available.
| Tk::HyperText - An ROText widget which renders HTML code. |