Retrieving variables (document metadata) from a MultiMarkdown document with PHP - php

How can I retrieve MultiMarkdown document metadata (as defined here) using php?
I was rather surprised that I couldn't find a MultiMarkdown php parser, PHP Markdown Extra doesn't do MultiMarkdown.
I'm afraid that the scripts that MultiMarkdown's comes packaged with have all the answers for somebody that would know how to define/use a custom XSLT, but sadly that's not my case.
MultiMarkdown Document Metadata goes like this:
Title: A New MultiMarkdown Document
Author: Fletcher T. Penney
John Doe
Date: July 25, 2005
I would like to use my own properties and control where they will be displayed in the output. By default, mmd2XHTML outputs the above (pre-defined) variables in tags, but I need to display them somewhere in the HTML body.
thanks

I am not an expert in php, but the easiest way would probably be to call out to the multimarkdown binary as a shell command, e.g.
multimarkdown -e title foo.txt
This command would output the value of the title metadata for foo.txt.
This is basically the approach I use in perl, Objective-C, and shell scripts, and is the reason I added the -e flag to MultiMarkdown to begin with.
The XSLT approach is great if you are using MMD to actually generate the HTML result, but probably not as useful in this circumstance.
Your other option would be to write a custom regular expression to grab what you need, but why reinvent the wheel?

for parsing markdown files with metadata you can use front yaml or kurenai
i am not sure about exact compatibility with multimarkdown.
front yaml
$parser = new Mni\FrontYAML\Parser();
$document = $parser->parse($str);
$yaml = $document->getYAML();
$html = $document->getContent();
kurenai
kurenai can parse different metadata content types like yaml and json.
$kurenai = new \Kurenai\Parser(
new \Kurenai\Parsers\Metadata\JsonParser,
new \Kurenai\Parsers\Content\MarkdownParser
);
$document = $kurenai->parse('path/to/document.md');
$document->getRaw();
$document->getMetadata();
$document->getContent();

Related

How to convert HTML into XHTML [duplicate]

This question already has an answer here:
Closed 10 years ago.
Possible Duplicate:
PHP library for converting HTML4 to XHTML?
Is there any ready made function in PHP to achieve this? Basically I'm taking HTML data from Smarty template and want to convert it into XHTML through coding.
$filename = 'template.php'; // filepath to file
// All options : http://tidy.sourceforge.net/docs/quickref.html
$options = array('output-xhtml' => true, 'clean' => true, 'wrap-php' => true);
$tidy = new tidy(); // create new instance of Tidy
$tidy->parseFile($filename, $options); // open file
$tidy->cleanRepair(); // process with specified options
copy($filename, $filename . '.bak'); // backup current file
file_put_contents($filename, $tidy); // overwrite current file with XHTML version
I don't have a Smarty template file to test this on, but give it a try and see if it works correctly in converting one. Backup your files as always when running something of this nature. Test out on sample files first.
The problem is that you do not have an html file to work with. You have a php template written in the programming language "smarty" that is not markup, even though it contains blocks of markup. You're looking for a magic wand and no such wand exists.
If it was purely html, then you could probably use Domdocument to read the files into a Dom structure and generate xhtml, but that is simply not going to work with the pure source files, although you could potentially write a parser to read the smarty tpl files, look for the html snippets and try and load them into Domdocument objects.
With that said, I have to ask first -- why you really want to convert to xhtml when xhtml is basically a failed standard that is obsolete at this point in time, and secondarily, if you have some legitimate reason for wanting to forge ahead, why you can't use some regex search and replace snippets that change the doctypes and some regex based searches to look for tags that lack the end tags, and the other relatively minor tweaks needed. The differences between html and xhtml can be boiled down to a handful of rules that are pretty easy to understand.
In answer to your original question: sort of. Core PHP -> DOM, SimpleXML, SPL = templating engine. That's why (and how) templating engines such as Smarty exist.
Re: installing Tidy as suggested in comments,
Tidy has a prerequisite lib. If you don't already have it:
http://php.net/manual/en/tidy.installation.php
To use Tidy, you will need libtidy installed, available on the tidy homepage »
http://tidy.sourceforge.net/.
To enable, you will need to recompile PHP and include it in your config flags:
"This extension is bundled with PHP 5 and greater, and is installed
using the --with-tidy configure option."
So, get your existing config flags:
php -i | grep config
and add --with-tidy.
However, this is probably the wrong approach. It does not solve your actual problem (outputting XHTML instead of HTML) - it fixes Smarty's problem. Recompiling PHP to add an extension so you can use it to fix a templating engine's doctype shortcomings probably means you should consider using a different templating engine, if possible. That's sort of drastic (and adds a lot of overhead for what you get, which amounts to for a hacky non-solution bandaid workaround retroactively repairing broken output.)
PEAR's HTML_Template_PHPTAL is probably the best solution to your problem, and the closest answer to your original question.
And if PHPTAL doesn't quite cut it, there are at least 5 others available as PEAR libs to choose from.
pear install http://phptal.org/latest.tar.gz
Or it's been ported to Git:
git clone git://github.com/pornel/PHPTAL
A cursory google search: http://webification.com/best-php-template-engines
HTH

Mediawiki tag extension - chained tags do not get processed

I'm trying to develop a simple Tag Extension for Mediawiki. So far I'm basically outputing the input as it comes. The problem arises when there are chained tags. For instance, for this example:
function efSampleParserInit( Parser &$parser ) {
$parser->setHook( 'sample', 'efSampleRender' );
return true;
}
function efSampleRender( $input, array $args, Parser $parser, PPFrame $frame ) {
return "hello ->" . $input . "<- hello";
}
If I write this in an article:
This is the text <sample type="1">hello my <sample type="2">brother</sample> John</sample>
Only the first sample tag gets processed. The other one isn't. I guess I should work with the $parser object I receive so I return the parsed input, but I don't know how to do it.
Furthermore, Mediawiki's reference is pretty much non existant, it would be great to have something like a Doxygen reference or something.
Use $parser->recursiveTagParse(), as shown at Manual:Tag_extensions#How do I render wikitext in my extension?.
It is kind of a clunky interface, and not very well documented. The underlying reason why such a seemingly natural thing to do is so tricky to accomplish is that it sort of goes against the original design intent of tag extensions — they were originally conceived as low-level filters that take in raw unparsed text and spit out HTML, completely bypassing normal parsing. So, for example, if you wanted to include some content written in Markdown (such as a StackOverflow post) on a wiki page, the idea was that you could install a suitable extension and then write
<markdown>
**Look,** here's some Markdown text!
</markdown>
on the page, and the MediaWiki parser would leave everything between the <markdown> tags alone and just hand it over to the extension for parsing.
Of course, it turned out that most people who wrote MediaWiki tag extensions didn't really want to replace the parser, but just to apply some tweaks to it. But the way the tag extension interface was set up, the only way to do that was to call the parser recursively. I've sometimes thought it would be nice to add a new parser extension type to MediaWiki, something that looked like tag extensions but didn't interrupt normal parsing in such a drastic manner. Alas, my motivation and copious free time hasn't so far been sufficient to actually do something about it.

Why use an XML parser?

I'm a somewhat experienced PHP scripter, however I just dove into parsing XML and all that good stuff.
I just can't seem to wrap my head around why one would use a separate XML parser instead of just using the explode function, which seems to be just as simple. Here's what I've been doing (assuming there is a valid XML file at the path xml.php):
$contents = file_get_contents("xml.php");
$array1 = explode("<a_tag>", $contents);
$array2 = explode("</a_tag>", $array1[1]);
$data = $array2[0];
So my question is, what is the practical use for an XML parser if you can just separate the values into arrays and extract the data from that point?
Thanks in advance! :)
Excuse me for not going into details but for starters try parsing
$contents = '<a xmlns="urn:something">
<a_tag>
<b>..</b>
<related>
<a_tag>...</a_tag>
</related>
</a_tag>
<foo:a_tag xmlns:foo="urn:something">
<![CDATA[This is another <a_tag> element]]>
</foo:a_tag>
</a>';
with your explode-approach. When you're done we can continue with some trickier things ;-)
In a nutshell, its consistency. Before XML came into wide use there were numerous undocumented formats for keeping information in files. One of the motivators behind XML was to create a well defined, standard document format. With this well defined format in place, a general set of parsing tools could be developed that would work consistently on documents so long as the documents adhered to the aforementioned well defined format.
In some specific cases, your example code will work. However, if the document changes
...
<!-- adding an attribute -->
<a_tag foo="bar">Contents of the Tag</a_tag>
...
...
<!-- adding a comment to the contents -->
<a_tag>Contents <!-- foobar --> of the Tag</a_tag>
...
Your parsing code will probably break. Code written using a correctly defined XML parser will not.
XML parsers:
Handle encoding
May have xpath support
Allow you to easily modify and save the XML; append/remove child nodes, add/remove attributes, etc.
Don't need to load the whole file into memory (except from DOM parsers)
Know about namespaces
...
How would you explode the same file if a_tag had an attribute?
explode("<a_tag>" ... will work differently than explode("<a_tag attr='value'>" ..., after all.
XML Parsers understand the XML specification. Explode can only handle the simplest of cases, and will most likely fail in a lot of instances of that case.
Using a proven XML parsing method will make the code more maintainable and easy to read. It will also make it more easily adaptable should the schema change, and it can make it easier to determine error conditions. XPath and XSLT exist for a reason, they are proven ways to deal with XML data in a sensible, legible manner. I'd suggest you use whichever is applicable in your given situation. Remember, just because you think you're only writing code for one specific purpose, you never know what a piece of well-written code could evolve into.

Template extraction in python/php

Are there existing template extract libraries in either python or php? Perl has Template::Extract, but I haven't been able to find a similar implementation in either python or php.
The only thing close in python that I could find is TemplateMaker (http://code.google.com/p/templatemaker/), but that's not really a template extraction library.
After digging around some more I found a solution to exactly what I was looking for. filippo posted a list of python solutions for screen scraping in this post: Options for HTML scraping? among which is a package called scrapemark ( http://arshaw.com/scrapemark/ ).
Hope this helps anyone else who is looking for the same solution.
TmeplateMaker does seem to do what you need, at least according to its documentation. Instead of receiving a template as an input, it infers ("learns") if from a few documents. Then, it has the extract method to extract the data from other documents that were created with this template.
The example shows:
# Now that we have a template, let's extract some data.
>>> t.extract('<b>red and green</b>')
('red', 'green')
>>> t.extract('<b>django and stephane</b>')
('django', 'stephane')
# The extract() method is very literal. It doesn't magically trim
# whitespace, nor does it have any knowledge of markup languages such as
# HTML.
>>> t.extract('<b> spacy and <u>underlined</u></b>')
(' spacy ', '<u>underlined</u>')
# The extract() method will raise the NoMatch exception if the data
# doesn't match the template. In this example, the data doesn't have the
# leading and trailing "<b>" tags.
>>> t.extract('this and that')
Traceback (most recent call last):
...
So, to achieve the task you require, I think you should:
Give it a few documents rendered from your template - it will have no trouble inferring the template from them.
Use the inferred template to extract data from new documents.
Come to think about it, it's even more useful than Perl's Template::Extract as it doesn't expect you to provide it a clean template - it learns it on its own from sample text.
Here is an interesting discussion from Adrian the author of TemplateMaker http://www.holovaty.com/writing/templatemaker/
It seems to be a lot like what I would call a wrapper induction library.
If your looking for something else that is more configurable (less for scraping) take a look at lxml.html and BeautifulSoup, also for python.

"Safe" markdown processor for PHP?

Is there a PHP implementation of markdown suitable for using in public comments?
Basically it should only allow a subset of the markdown syntax (bold, italic, links, block-quotes, code-blocks and lists), and strip out all inline HTML (or possibly escape it?)
I guess one option is to use the normal markdown parser, and run the output through an HTML sanitiser, but is there a better way of doing this..?
We're using PHP markdown Extra for the rest of the site, so we'd already have to use a secondary parser (the non-"Extra" version, since things like footnote support is unnecessary).. It also seems nicer parsing only the *bold* text and having everything escaped to <a href="etc">, than generating <b>bold</b> text and trying to strip the bits we don't want..
Also, on a related note, we're using the WMD control for the "main" site, but for comments, what other options are there? WMD's javascript preview is nice, but it would need the same "neutering" as the PHP markdown processor (it can't display images and so on, otherwise someone will submit and their working markdown will "break")
Currently my plan is to use the PHP-markdown -> HTML santiser method, and edit WMD to remove the image/heading syntax from showdown.js - but it seems like this has been done countless times before..
Basically:
Is there a "safe" markdown implementation in PHP?
Is there a HTML/javascript markdown editor which could have the same options easily disabled?
Update: I ended up simply running the markdown() output through HTML Purifier.
This way the Markdown rendering was separate from output sanitisation, which is much simpler (two mostly-unmodified code bases) more secure (you're not trying to do both rendering and sanitisation at once), and more flexible (you can have multiple sanitisation levels, say a more lax configuration for trusted content, and a much more stringent version for public comments)
PHP Markdown has a sanitizer option, but it doesn't appear to be advertised anywhere. Take a look at the top of the Markdown_Parser class in markdown.php (starts on line 191 in version 1.0.1m). We're interested in lines 209-211:
# Change to `true` to disallow markup or entities.
var $no_markup = false;
var $no_entities = false;
If you change those to true, markup and entities, respectively, should be escaped rather than inserted verbatim. There doesn't appear to be any built-in way to change those (e.g., via the constructor), but you can always add one:
function do_markdown($text, $safe=false) {
$parser = new Markdown_Parser;
if ($safe) {
$parser->no_markup = true;
$parser->no_entities = true;
}
return $parser->transform($text);
}
Note that the above function creates a new parser on every run rather than caching it like the provided Markdown function (lines 43-56) does, so it might be a bit on the slow side.
JavaScript Markdown Editor Hypothesis:
Use a JavaScript-driven Markdown Editor, e.g., based on showdown
Remove all icons and visual clues from the Toolbar for unwanted items
Set up a JavaScript filter to clean-up unwanted markup on submission
Test and harden all JavaScript changes and filters locally on your computer
Mirror those filters in the PHP submission script, to catch same on the server-side.
Remove all references to unwanted items from Help/Tutorials
I've created a Markdown editor in JavaScript, but it has enhanced features. That took a big chunk of time and SVN revisions. But I don't think it would be that tough to alter a Markdown editor to limit the HTML allowed.
How about running htmlspecialchars on the user entered input, before processing it through markdown? It should escape anything dangerous, but leave everything that markdown understands.
I'm trying to think of a case where this wouldn't work but can't think of anything off hand.

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