{ "mode": "perldoc", "parameter": "HTML::TreeBuilder", "section": "", "url": "https://www.chedong.com/phpMan.php/perldoc/HTML%3A%3ATreeBuilder/json", "generated": "2026-06-10T03:52:01Z", "synopsis": "use HTML::TreeBuilder 5 -weak; # Ensure weak references in use\nforeach my $filename (@ARGV) {\nmy $tree = HTML::TreeBuilder->new; # empty tree\n$tree->parsefile($filename);\nprint \"Hey, here's a dump of the parse tree of $filename:\\n\";\n$tree->dump; # a method we inherit from HTML::Element\nprint \"And here it is, bizarrely rerendered as HTML:\\n\",\n$tree->asHTML, \"\\n\";\n# Now that we're done with it, we must destroy it.\n# $tree = $tree->delete; # Not required with weak references\n}", "sections": { "NAME": { "content": "HTML::TreeBuilder - Parser that builds a HTML syntax tree\n", "subsections": [] }, "VERSION": { "content": "This document describes version 5.07 of HTML::TreeBuilder, released August 31, 2017 as part of\nHTML-Tree.\n", "subsections": [] }, "SYNOPSIS": { "content": "use HTML::TreeBuilder 5 -weak; # Ensure weak references in use\n\nforeach my $filename (@ARGV) {\nmy $tree = HTML::TreeBuilder->new; # empty tree\n$tree->parsefile($filename);\nprint \"Hey, here's a dump of the parse tree of $filename:\\n\";\n$tree->dump; # a method we inherit from HTML::Element\nprint \"And here it is, bizarrely rerendered as HTML:\\n\",\n$tree->asHTML, \"\\n\";\n\n# Now that we're done with it, we must destroy it.\n# $tree = $tree->delete; # Not required with weak references\n}\n", "subsections": [] }, "DESCRIPTION": { "content": "(This class is part of the HTML::Tree dist.)\n\nThis class is for HTML syntax trees that get built out of HTML source. The way to use it is to:\n\n1. start a new (empty) HTML::TreeBuilder object,\n\n2. then use one of the methods from HTML::Parser (presumably with \"$tree->parsefile($filename)\"\nfor files, or with \"$tree->parse($documentcontent)\" and \"$tree->eof\" if you've got the content\nin a string) to parse the HTML document into the tree $tree.\n\n(You can combine steps 1 and 2 with the \"newfromfile\" or \"newfromcontent\" methods.)\n\n2b. call \"$root->elementify()\" if you want.\n\n3. do whatever you need to do with the syntax tree, presumably involving traversing it looking\nfor some bit of information in it,\n\n4. previous versions of HTML::TreeBuilder required you to call \"$tree->delete()\" to erase the\ncontents of the tree from memory when you're done with the tree. This is not normally required\nanymore. See \"Weak References\" in HTML::Element for details.\n", "subsections": [] }, "ATTRIBUTES": { "content": "Most of the following attributes native to HTML::TreeBuilder control how parsing takes place;\nthey should be set *before* you try parsing into the given object. You can set the attributes by\npassing a TRUE or FALSE value as argument. E.g., \"$root->implicittags\" returns the current\nsetting for the \"implicittags\" option, \"$root->implicittags(1)\" turns that option on, and\n\"$root->implicittags(0)\" turns it off.\n\nimplicittags\nSetting this attribute to true will instruct the parser to try to deduce implicit elements and\nimplicit end tags. If it is false you get a parse tree that just reflects the text as it stands,\nwhich is unlikely to be useful for anything but quick and dirty parsing. (In fact, I'd be\ncurious to hear from anyone who finds it useful to have \"implicittags\" set to false.) Default\nis true.\n\nImplicit elements have the \"implicit\" in HTML::Element attribute set.\n\nimplicitbodyptag\nThis controls an aspect of implicit element behavior, if \"implicittags\" is on: If a text\nelement (PCDATA) or a phrasal element (such as \"\") is to be inserted under \"\", two\nthings can happen: if \"implicitbodyptag\" is true, it's placed under a new, implicit \"

\"\ntag. (Past DTDs suggested this was the only correct behavior, and this is how past versions of\nthis module behaved.) But if \"implicitbodyptag\" is false, nothing is implicated -- the PCDATA\nor phrasal element is simply placed under \"\". Default is false.\n\nnoexpandentities\nThis attribute controls whether entities are decoded during the initial parse of the source.\nEnable this if you don't want entities decoded to their character value. e.g. '&' is decoded\nto '&' by default, but will be unchanged if this is enabled. Default is false (entities will be\ndecoded.)\n\nignoreunknown\nThis attribute controls whether unknown tags should be represented as elements in the parse\ntree, or whether they should be ignored. Default is true (to ignore unknown tags.)\n\nignoretext\nDo not represent the text content of elements. This saves space if all you want is to examine\nthe structure of the document. Default is false.\n\nignoreignorablewhitespace\nIf set to true, TreeBuilder will try to avoid creating ignorable whitespace text nodes in the\ntree. Default is true. (In fact, I'd be interested in hearing if there's ever a case where you\nneed this off, or where leaving it on leads to incorrect behavior.)\n\nnospacecompacting\nThis determines whether TreeBuilder compacts all whitespace strings in the document (well,\noutside of PRE or TEXTAREA elements), or leaves them alone. Normally (default, value of 0), each\nstring of contiguous whitespace in the document is turned into a single space. But that's not\ndone if \"nospacecompacting\" is set to 1.\n\nSetting \"nospacecompacting\" to 1 might be useful if you want to read in a tree just to make\nsome minor changes to it before writing it back out.\n\nThis method is experimental. If you use it, be sure to report any problems you might have with\nit.\n\npstrict\nIf set to true (and it defaults to false), TreeBuilder will take a narrower than normal view of\nwhat can be under a \"

\" element; if it sees a non-phrasal element about to be inserted under a\n\"

\", it will close that \"

\". Otherwise it will close \"

\" elements only for other \"

\"'s,\nheadings, and \"

\" (although the latter may be removed in future versions).\n\nFor example, when going thru this snippet of code,\n\n

stuff\n