NAME YAPE::HTML - Yet Another Parser/Extractor for HTML SYNOPSIS use YAPE::HTML; use strict; my $content = "..."; my $parser = YAPE::HTML->new($content); my ($extor,@fonts,@urls,@headings,@comments); # here is the tokenizing part while (my $chunk = $parser->next) { if ($chunk->type eq 'tag' and $chunk->tag eq 'font') { if (my $face = $chunk->get_attr('face')) { push @fonts, $face; } } } # here we catch any errors unless ($parser->done) { die sprintf "bad HTML: %s (%s)", $parser->error, $parser->chunk; } # here is the extracting part # tags with HREF attributes # tags with SRC attributes $extor = $parser->extract(a => ['href'], img => ['src']); while (my $chunk = $extor->()) { push @urls, $chunk->get_attr( $chunk->tag eq 'a' ? 'href' : 'src' ); } #


, ...,

tags $extor = $parser->extract(qr/^h[1-6]$/ => []); while (my $chunk = $extor->()) { push @headings, $chunk; } # all comments $extor = $parser->extract(-COMMENT => []); while (my $chunk = $extor->()) { push @comments, $chunk; } `YAPE' MODULES The `YAPE' hierarchy of modules is an attempt at a unified means of parsing and extracting content. It attempts to maintain a generic interface, to promote simplicity and reusability. The API is powerful, yet simple. The modules do tokenization (which can be intercepted) and build trees, so that extraction of specific nodes is doable. DESCRIPTION This module is yet another parser and tree-builder for HTML documents. It is designed to make extraction and modification of HTML documents simplistic. The API allows for easy custom additions to the document being parsed, and allows very specific tag, text, and comment extraction. USAGE In addition to the base class, `YAPE::HTML', there is the auxiliary class `YAPE::HTML::Element' (common to all `YAPE' base classes) that holds the individual nodes' classes. There is documentation for the node classes in that module's documentation. HTML elements and their attributes are stored internally as lowercase strings. For clarification, that means that the tag `' is stored as { TAG => 'a', ATTR => { href => 'FooBar.html', } } This means that tags will be output in lowercase. There will be a feature in a future version to switch output case to capital letters. Functions * `YAPE::HTML::EMPTY(@tags)' Adds to the internal hash of tags which never contain any out-of-tag content. This hash is `%YAPE::HTML::EMPTY', and contains the following tag names: `area', `base', `br', `hr', `img', `input', `link', `meta', and `param'. Deletion from this hashmust be done manually. Adding to this hash automatically adds to the `%OPEN' hash, described next. * `YAPE::HTML::OPEN(@tags)' Adds to the internal hash of tags which do not require a closing tag. This hash is `%YAPE::HTML::OPEN', and contains the following tag names: `area', `base', `br', `dd', `dt', `hr', `img', `input', `li', `link', `meta', `p', and `param'. Deletion from this hash must be done manually. There is a subtle difference between "empty" and "open" tags. For example, the `' tag contains a few attributes, but there is no text associated with it (nor any other tags), and therefore, is "empty"; the `
  • ', on the other hand, It is strongly suggested that for ease in parsing, any tags that you do not explicitly close have a `/' at the end of the tag: Here's my cat: Methods for `YAPE::HTML' * `use YAPE::HTML;' * `use YAPE::HTML qw( MyExt::Mod );' If supplied no arguments, the module is loaded normally, and the node classes are given the proper inheritence (from `YAPE::HTML::Element'). If you supply a module (or list of modules), `import' will automatically include them (if needed) and set up *their* node classes with the proper inheritence -- that is, it will append `YAPE::HTML' to `@MyExt::Mod::ISA', and `YAPE::HTML::xxx' to each node class's `@ISA' (where `xxx' is the name of the specific node class). It also copies the `%OPEN' and `%EMPTY' hashes, as well as the `OPEN()' and `EMPTY()' functions, into the `MyExt::Mod' namespace. This process is designed to save you from having to place `@ISA' assignments all over the place. It also copies the `%SSI' hash. This hash is not suggested to be altered, and therefore it does not have any public interface (you have to fiddle with it yourself). It exists to ensure an SSI is valid. package MyExt::Mod; use YAPE::HTML 'MyExt::Mod'; # @MyExt::Mod::ISA = 'YAPE::HTML' # @MyExt::Mod::text::ISA = 'YAPE::HTML::text' # ... # being rather strict with the tags %OPEN = (); %EMPTY = (); * `my $p = YAPE::HTML->new($HTML, $strict);' Creates a `YAPE::HTML' object, using the contents of the `$HTML' string as its HTML to parse. The optional second argument determines whether this parser instance will demand strict comment parsing and require all tags to be closed with a closing tag or a `/' at the end of the tag (`
    '). Any true value (except for the special string `- NO_STRICT') will turn strict parsing on. This is off by default. (This could be considered a bug.) * `my $text = $p->chunk($len);' Returns the next `$len' characters in the input string; `$len' defaults to 30 characters. This is useful for figuring out why a parsing error occurs. * `my $done = $p->done;' Returns true if the parser is done with the input string, and false otherwise. * `my $errstr = $p->error;' Returns the parser error message. * `my $coderef = $p->extract(...);' Returns a code reference that returns the next object that matches the criteria given in the arguments. This is a fundamental feature of the module, and you can extract that from the section on "Extracting Sections". * `my $node = $p->display(...);' Returns a string representation of the entire content. It calls the `parse' method in case there is more data that has not yet been parsed. This calls the `fullstring' method on the root nodes. Check the `YAPE::HTML::Element' docs on the arguments to `fullstring'. * `my $node = $p->next;' Returns the next token, or `undef' if there is no valid token. There will be an error message (accessible with the `error' method) if there was a problem in the parsing. * `my $node = $p->parse;' Calls `next' until all the data has been parsed. * `my $attr = $p->quote($string);' Returns a quoted string, suitable for using as an attribute. It turns any embedded `"' characters into `"'. This can also be called as a raw function: my $quoted = YAPE::HTML::quote($string); * `my $root = $p->root;' Returns an array reference holding the root of the tree structure -- for documents that contain multiple top-level tags, this will have more than one element. * `my $state = $p->state;' Returns the current state of the parser. It is one of the following values: `close(TAG)', `comment', `done', `dtd', `error', `open(TAG)', `pi', `ssi', `text', `text(script)', or `text(xmp)'. The `open' and `close' states contain the name of the element in parentheses (ex. `open(img)'). Tag names, as well as the names of attributes, are converted to lowercase. The state of `text(script)' refers to text found inside an `