WikiFile:Wikka

Revision [16033]

This is an old revision of WikiFile made by ChewBakka on 2007-02-02 17:35:16.

In Wikka, almost everything is a page.

For example, a category is a page to which other pages link. If you want to stat a new category, you do not need to learn something new - just create the category page and link your pages to it.

Here I would like to present a solution where files are represented by pages too. I will first give a description on how to use it, then the necessary pieces of code.

Description

On the server side, there are no file names any more - any file is "contained" in a particular page and referenced using only the page name. If the file is an image, it is visible in the page (through the { {file} } action) along with explaining text which is writen in the page as usual. The access rights for viewing and mpdifying files are just the page rights.

I order to add a screenshot (or any other file) to your wiki, you will first create a page for it. This is something youshould do anyway, because you should write some explaining text about your screenshot. The page should include a { {file} } action to your page, although this is not necessary for being a file page - it is just for file pages what the { {category} } action is for category pages.

The page footer reads Edit page :: File :: Stats :: Referrers and so on - note the addition of File. Clicking on it opens the file handler, which displays informations about the file (if there is already a file in the page) and an upload form; uploading a file into a page which already contains a file causes the old file to be replaced with the new file - there can be only one file per page.

Code

Below are five pieces of code. The files Wakka.class.php and footer.php are parts of the Wikka software; I have extended them without changing existing functions (hopefully). I have also added two files: actions/file.php and handlers/page/file.php.

Here comes the modification of actions/footer.php; lines 5,6,7 are added, anything else remains unchanged. This adds File:: to the footer.

<div class="footer">
<?php
echo $this->FormOpen("", "TextSearch", "get");
echo $this->HasAccess("write") ? "<a href=\"".$this->href("edit")."\" title=\"Click to edit this page\">Edit page</a> ::\n" : "";
echo ($this->HasAccess("write") || $this->HasAccess("read"))
? '<a href="' . $this->href("file"). '" title="Click to view/edit the file in this page">File</a> ::' . "\n"
: '';
// ...

In Wakka.class.php I have extended the FormOpen function, because the html form must include an encoding attribute if you want to upload files. I have added a fourth parameter named $withFiles. This is the extended function:

function FormOpen($method = "", $tag = "", $formMethod = "post", $withFile = false )
{
$enctype = '';
if ($withFile) $enctype = ' enctype="multipart/form-data"';
$result = "<form action=\"".$this->Href($method, $tag)."\" method=\"".$formMethod."\"$enctype>\n";
if (!$this->config["rewrite_mode"]) $result .= "<input type=\"hidden\" name=\"wakka\" value=\"".$this->MiniHref($method, $tag)."\" />\n";
return $result;
}

Also in Wakka.class.php I have added four functions which perform the most basic file handling without access right checking. (One function is actually only a workaround for probllems with mime_content_type() which I experienced). I have just added them and the end of the class, and they look like this:

/**
* Return mime type for the given file extension.
* Slow, but useful if PHP's mime_content_type() cannot be used.
* Uses Wikka's mime_types.txt and some hardcoded associations.
*
* @author {@link http://wikkawiki.org/ChewBakka ChewBakka} (first draft)
* @input $extension file extension, e.g. 'png', 'jpg', 'ogg'
* @output mime content type, e.g. 'image/png', or empty string.
*/
function MimeTypeFromExtension( $extension )
{
// Quick resonse for most frequently used file types
if ($extension == 'png') return 'image/png';
if ($extension == 'jpg') return 'image/jpeg';
if ($extension == 'ogg') return 'application/ogg';
// If not recoginzed, use mime_types.txt
if (file_exists( $this->config['mime_types'] ))
{
foreach (explode("\n",file_get_contents($this->config['mime_types'])) as $line)
{
$line = trim($line);
if ($line != '' && substr($line,0,1) != '#' && strpos($line,$extension))
{
$a = explode( ' ', str_replace(chr(9),' ',$line) );
if (in_array( $extension, $a ))
{
return $a[0];
}
}
}
}
return ''; // if nothing was found
}
/**
* Return an array describing the file which is stored in a page.
*
* @author {@link http://wikkawiki.org/ChewBakka ChewBakka} (first draft)
* @input $tag name of the page; default = current page.
* @output Array or (if no file in page) null. Keys:
* extension file extension, e.g. 'png', 'jpg', 'ogg'
* content-type mime content type, e.g. 'image/png'
* uploaded when and who,. e.g. '2007-01-31 ChewBakka'
* image 'yes' or 'no'
* width Width in pixels (images only)
* height Height in pixels (images only)
* filename PageName.extension
* path upload_path/PageName.extension
* url 'http://..../PageName/file?action=get'
*/
function GetFile( $tag = '' )
{
$data = null; // this variable will be returned
if (!$tag) $tag = $this->tag;
$metafile = $this->config['upload_path'].'/'.$tag.'.file'; // metadata
if (file_exists($metafile) && $contents = file_get_contents($metafile))
{
$lines = explode( "\n", $contents );
// Lines look like "key: value" -> convert into array
$data = array(
'extension' => '',
'content-type' => '',
'uploaded' => '',
'image' => 'false',
'width' => '',
'height' => '',
'filename' => '',
'path' => '',
'url' => ''
);
foreach ($lines as $line)
{
$a = explode( ":", trim($line), 2 );
if( count($a) == 2 )
{
$data[ $a[0] ] = trim( $a[1] );
}
}
// Convenient attributes which can not be stored permanently
$data['filename'] = $tag . '.' . $data['extension'];
$data['path'] = $this->config['upload_path'] .'/' . $data['filename'];
$data['url'] = $this->config['base_url'] . $tag . '/file' .
($this->config['rewrite_mode']=='1' ? '?' : '&') .
'action=get';
// Final check: file must exist.
if (! file_exists( $data['path'] ) )
{
$data = null;
}
}
return $data;
}
/**
* Remove the file from the current page.
*
* @author {@link http://wikkawiki.org/ChewBakka ChewBakka} (first draft)
* @input none
* @output none
*/
function RemoveFile()
{
if ($data = $this->GetFile())
{
unlink( $this->config['upload_path'] . '/' . $this->tag . '.file' );
unlink( $this->config['upload_path'] . '/' . $data['filename'] );
}
}
/**
* Store an http-uploaded file in the current page.
* Any previous file will be replaced with the new file.
*
* @author {@link http://wikkawiki.org/ChewBakka ChewBakka} (first draft)
* @input $uploaded_file An item from PHP's $_FILES array (see there)
* @output None
*/
function SaveFile( $uploaded_file )
{
$this->RemoveFile();
$pathinfo = pathinfo( $uploaded_file['name'] );
$extension = strtolower( $pathinfo['extension'] );
$pathname = $this->config['upload_path'] . '/' . $this->tag;
$path = $pathname . '/' . $extension;
if (move_uploaded_file( $uploaded_file['tmp_name'], $path ))
{
$contenttype = mime_content_type($path);
if( ! $contenttype )
{
$contenttype = $this->MimeTypeFromExtension( $extension );
}
// build an array with metadata
$data = array(
'extension' => $extension,
'content-type' => $contenttype,
'uploaded' => date('Y-m-d H:i') . ' ' . $this->GetUserName(),
'image' => 'false'
);
if( substr($data['content-type'],0,6) == 'image/' )
{
$data['image'] = 'true';
$size = getimagesize($path);
$data['width'] = $size[0];
$data['height'] = $size[1];
}
// Create metadata file
$contents = '';
foreach ($data as $key => $value)
{
$contents .= ($key . ': ' . $value . "\n");
}
file_put_contents( $pathname . '.file', $contents );
}
}

The remaining two code pieces are two new files. Both are named file.php, but one is a handler and the other one is the action.

Here comes handlers/page/file.php:

/php;1)
<?php

/**
 * Display file info and a small upload form.
 *
 * @package Handlers
 * @name    File
 *
 * @author  {@link http://wikkawiki.org/ChewBakka ChewBakka} (first draft)
 *
 * @input   ?action=get returns the file via http
 *          uploading a file causes storage of the file "in the page",
 *          overwriting any previous page file.
 *
 */

$has_read_access  = $this->HasAccess('read');
$has_write_access = $this->HasAccess('write') && $has_read_access;

switch (True) 
{
	case $_REQUEST['action'] == 'get':
		// ?action=get
		if ($this->HasAccess('read') && $data = $this->GetFile())
		{
			header('Content-Type: ' . $data['content-type'] );
			@readfile($data['path']);
			exit();
		}
	case isset($_FILES['file']):
		// User uploaded a file
		if ($has_write_access)
		{
			$uploadedfile = $_FILES['file'];
			if ($uploadedfile['error'] > 0)
			{
				// redirect to page
				$this->redirect( $this->Href(), 'Transmitted file was damaged' );
			} 
			else
			{
				$this->SaveFile( $uploadedfile );
				$this->Redirect( $this->Href() );
			}
		}
	default:
		// Display file info and an upload form
		$data = null;
		if ($has_read_access)
		{
			if ($data = $this->GetFile())
			{
				print '<h3>Existing file</h3><p>';
				foreach ($data as $key => $value)
				{
					if ($key != 'url')
					{
						print htmlspecialchars(htmlentities($key))   . ': ' .
							  htmlspecialchars(htmlentities($value)) . '<br />';
					}
				}
				$a = '< href="' . $data['url'] . '">' . $data['url'] . '</a>';
 				print 'url: ' . $this->ReturnSafeHTML($a) . '<br />';
				print 'Wikka syntax: {{file page="' . $this->GetPageTag() . '"}}' . '<br />';
				print '</p>';
			}
			else
			{
				print '<p>There is no file yet</p>';
			}
		}
		else
		{
			print '<div class="page"><em>Sorry, you are nor allowed to view this file.</em></div>';
		}
		if ($has_write_access)
		{
			print '<h3>Upload form</h3><p>';
			print $this->FormOpen( 'file', $this->GetPageTag(), 'POST', true );
			print '<input name="file" type="file" size="72">';
			print '<input type="submit" value="upload">';
			print $this->FormClose();
			if ($data) print '<p>Note: the uploaded file will <em>replace</em> the existing file.</p>';
		}
		else
		{
			print '<div class="page"><em>Sorry, you are nor allowed to put a file here.</em></div>';
		}
}

?>

And finally actions/file.php

<?php
/**
* Display the page's file, either inline or as link.
*
* If the file is an image, then it is displayed inline.
* For other file types, a download link is printed.
* Note that at most one file can be stored in a page.
*
* Syntax:
* {{file [page="SomeWikkaName"]}}
*
* @package Actions
* @name File
*
* @author {@link http://wikkawiki.org/ChewBakka ChewBakka} (first draft)
*
* @input string $page: name of the page whose file is to be displayed.
* optional; default is the current page itself.
*/
$tag = (is_array($vars) && array_key_exists('page',$vars)) ? $vars['page'] : $this->GetPageTag();
$output = '';
// Check whether current has read access and if there is a file.
if ($this->HasAccess( 'read', $tag ) && $data = $this->GetFile($tag))
{
if ($data['image'] == 'true')
{
// Image file - create an <img> tag
$output = '<img src="' . $data['url'] . '"' .
' width="' . $data['width'] . '"' .
' height="' . $data['height'] . '"' .
' alt="' . $tag . '">';
}
else
{
// Plain file - create a download link
$output = '<a href="' . $data['url'] . '">' . $data['url'] . '</a>';
}
}
print $this->ReturnSafeHTML($output);
?>

Wikka : WikiFile

Revision [16033]

Description

Code