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MediaHandler Class Reference
Inheritance diagram for MediaHandler:
Collaboration diagram for MediaHandler:

Public Member Functions

 getParamMap ()
 
 validateParam ($name, $value)
 
 makeParamString ($params)
 
 parseParamString ($str)
 
 normaliseParams ($image, &$params)
 
 getImageSize ($image, $path)
 
 getMetadata ($image, $path)
 
 convertMetadataVersion ($metadata, $version=1)
 
 getMetadataType ($image)
 
 isMetadataValid ($image, $metadata)
 
 getCommonMetaArray (File $file)
 
 getScriptedTransform ($image, $script, $params)
 
 getTransform ($image, $dstPath, $dstUrl, $params)
 
 doTransform ($image, $dstPath, $dstUrl, $params, $flags=0)
 
 getThumbType ($ext, $mime, $params=null)
 
 getStreamHeaders ($metadata)
 
 canRender ($file)
 
 mustRender ($file)
 
 isMultiPage ($file)
 
 pageCount (File $file)
 
 isVectorized ($file)
 
 isAnimatedImage ($file)
 
 canAnimateThumbnail ($file)
 
 isEnabled ()
 
 getPageDimensions (File $image, $page)
 
 getPageText (File $image, $page)
 
 getEntireText (File $file)
 
 formatMetadata ($image, $context=false)
 
 formatMetadataHelper ($metadataArray, $context=false)
 
 getShortDesc ($file)
 
 getLongDesc ($file)
 
 getDimensionsString ($file)
 
 parserTransformHook ($parser, $file)
 
 verifyUpload ($fileName)
 
 removeBadFile ($dstPath, $retval=0)
 
 filterThumbnailPurgeList (&$files, $options)
 
 canRotate ()
 
 getRotation ($file)
 
 getAvailableLanguages (File $file)
 
 getDefaultRenderLanguage (File $file)
 
 getLength ($file)
 
 isExpensiveToThumbnail ($file)
 
 supportsBucketing ()
 
 sanitizeParamsForBucketing ($params)
 
 getWarningConfig ($file)
 
 getContentHeaders ($metadata)
 

Static Public Member Functions

static getHandler ($type)
 
static getMetadataVersion ()
 
static getGeneralShortDesc ($file)
 
static getGeneralLongDesc ($file)
 
static fitBoxWidth ($boxWidth, $boxHeight, $maxHeight)
 
static getPageRangesByDimensions ($pagesByDimensions)
 

Public Attributes

const TRANSFORM_LATER = 1
 
const METADATA_GOOD = true
 
const METADATA_BAD = false
 
const METADATA_COMPATIBLE = 2
 
const MAX_ERR_LOG_SIZE = 65535
 

Protected Member Functions

 visibleMetadataFields ()
 
 logErrorForExternalProcess ($retval, $err, $cmd)
 

Static Protected Member Functions

static addMeta (&$array, $visibility, $type, $id, $value, $param=false)
 

Detailed Description

Base media handler class

Member Function Documentation

static MediaHandler::addMeta ( $array,
  $visibility,
  $type,
  $id,
  $value,
  $param = false 
)
staticprotected

This is used to generate an array element for each metadata value That array is then used to generate the table of metadata values on the image page

Parameters
array&$arrayAn array containing elements for each type of visibility and each of those elements being an array of metadata items. This function adds a value to that array.
string$visibility('visible' or 'collapsed') if this value is hidden by default.
string$typeType of metadata tag (currently always 'exif')
string$idThe name of the metadata tag (like 'artist' for example). its name in the table displayed is the message "$type-$id" (Ex exif-artist ).
string$valueThingy goes into a wikitext table; it used to be escaped but that was incompatible with previous practise of customized display with wikitext formatting via messages such as 'exif-model-value'. So the escaping is taken back out, but generally this seems a confusing interface.
bool | string$paramValue to pass to the message for the name of the field as $1. Currently this parameter doesn't seem to ever be used.

Note, everything here is passed through the parser later on (!)

MediaHandler::canAnimateThumbnail (   $file)

If the material is animated, we can animate the thumbnail

Since
1.20
Parameters
File$file
Returns
bool If material is not animated, handler may return any value.
MediaHandler::canRender (   $file)

True if the handled types can be transformed

Parameters
File$file
Returns
bool
MediaHandler::canRotate ( )

True if the handler can rotate the media

Since
1.24 non-static. From 1.21-1.23 was static
Returns
bool
MediaHandler::convertMetadataVersion (   $metadata,
  $version = 1 
)

Convert metadata version.

By default just returns $metadata, but can be used to allow media handlers to convert between metadata versions.

Parameters
string | array$metadataMetadata array (serialized if string)
int$versionTarget version
Returns
array Serialized metadata in specified version, or $metadata on fail.
MediaHandler::doTransform (   $image,
  $dstPath,
  $dstUrl,
  $params,
  $flags = 0 
)
abstract

Get a MediaTransformOutput object representing the transformed output. Does the transform unless $flags contains self::TRANSFORM_LATER.

Parameters
File$image
string$dstPathFilesystem destination path
string$dstUrlDestination URL to use in output HTML
array$paramsArbitrary set of parameters validated by $this->validateParam() Note: These parameters have not gone through $this->normaliseParams()
int$flagsA bitfield, may contain self::TRANSFORM_LATER
Returns
MediaTransformOutput
MediaHandler::filterThumbnailPurgeList ( $files,
  $options 
)

Remove files from the purge list.

This is used by some video handlers to prevent ?action=purge from removing a transcoded video, which is expensive to regenerate.

See Also
LocalFile::purgeThumbnails
Parameters
array&$files
array$optionsPurge options. Currently will always be an array with a single key 'forThumbRefresh' set to true.
static MediaHandler::fitBoxWidth (   $boxWidth,
  $boxHeight,
  $maxHeight 
)
static

Calculate the largest thumbnail width for a given original file size such that the thumbnail's height is at most $maxHeight.

Parameters
int$boxWidthWidth of the thumbnail box.
int$boxHeightHeight of the thumbnail box.
int$maxHeightMaximum height expected for the thumbnail.
Returns
int
MediaHandler::formatMetadata (   $image,
  $context = false 
)

Get an array structure that looks like this:

[ 'visible' => [ 'Human-readable name' => 'Human readable value', ... ], 'collapsed' => [ 'Human-readable name' => 'Human readable value', ... ] ] The UI will format this into a table where the visible fields are always visible, and the collapsed fields are optionally visible.

The function should return false if there is no metadata to display.

Todo:
FIXME: This interface is not very flexible. The media handler should generate HTML instead. It can do all the formatting according to some standard. That makes it possible to do things like visual indication of grouped and chained streams in ogg container files.
Parameters
File$image
bool | IContextSource$contextContext to use (optional)
Returns
array|bool
MediaHandler::formatMetadataHelper (   $metadataArray,
  $context = false 
)

sorts the visible/invisible field. Split off from ImageHandler::formatMetadata, as used by more than one type of handler.

This is used by the media handlers that use the FormatMetadata class

Parameters
array$metadataArray
bool | IContextSource$contextContext to use (optional)
Returns
array Array for use displaying metadata.
MediaHandler::getAvailableLanguages ( File  $file)

Get list of languages file can be viewed in.

Parameters
File$file
Returns
string[] Array of language codes, or empty array if unsupported.
Since
1.23
MediaHandler::getCommonMetaArray ( File  $file)

Get an array of standard (FormatMetadata type) metadata values.

The returned data is largely the same as that from getMetadata(), but formatted in a standard, stable, handler-independent way. The idea being that some values like ImageDescription or Artist are universal and should be retrievable in a handler generic way.

The specific properties are the type of properties that can be handled by the FormatMetadata class. These values are exposed to the user via the filemetadata parser function.

Details of the response format of this function can be found at https://www.mediawiki.org/wiki/Manual:File_metadata_handling tl/dr: the response is an associative array of properties keyed by name, but the value can be complex. You probably want to call one of the FormatMetadata::flatten* functions on the property values before using them, or call FormatMetadata::getFormattedData() on the full response array, which transforms all values into prettified, human-readable text.

Subclasses overriding this function must return a value which is a valid API response fragment (all associative array keys are valid XML tagnames).

Note, if the file simply has no metadata, but the handler supports this interface, it should return an empty array, not false.

Parameters
File$file
Returns
array|bool False if interface not supported
Since
1.23
MediaHandler::getContentHeaders (   $metadata)

Get useful response headers for GET/HEAD requests for a file with the given metadata

Parameters
array$metadataContains this handler's unserialized getMetadata() for a file
Returns
array
Since
1.30
MediaHandler::getDefaultRenderLanguage ( File  $file)

On file types that support renderings in multiple languages, which language is used by default if unspecified.

If getAvailableLanguages returns a non-empty array, this must return a valid language code. Otherwise can return null if files of this type do not support alternative language renderings.

Parameters
File$file
Returns
string|null Language code or null if multi-language not supported for filetype.
Since
1.23
MediaHandler::getDimensionsString (   $file)

Shown in file history box on image description page.

Parameters
File$file
Returns
string Dimensions
MediaHandler::getEntireText ( File  $file)

Get the text of the entire document.

Parameters
File$file
Returns
bool|string The text of the document or false if unsupported.
static MediaHandler::getGeneralLongDesc (   $file)
static

Used instead of getLongDesc if there is no handler registered for file.

Parameters
File$file
Returns
string
static MediaHandler::getGeneralShortDesc (   $file)
static

Used instead of getShortDesc if there is no handler registered for file.

Parameters
File$file
Returns
string
static MediaHandler::getHandler (   $type)
static

Get a MediaHandler for a given MIME type from the instance cache

Parameters
string$type
Returns
MediaHandler|bool
MediaHandler::getImageSize (   $image,
  $path 
)
abstract

Get an image size array like that returned by getimagesize(), or false if it can't be determined.

This function is used for determining the width, height and bitdepth directly from an image. The results are stored in the database in the img_width, img_height, img_bits fields.

Note
If this is a multipage file, return the width and height of the first page.
Parameters
File | FSFile$imageThe image object, or false if there isn't one. Warning, FSFile::getPropsFromPath might pass an FSFile instead of File (!)
string$pathThe filename
Returns
array|bool Follow the format of PHP getimagesize() internal function. See https://secure.php.net/getimagesize. MediaWiki will only ever use the first two array keys (the width and height), and the 'bits' associative key. All other array keys are ignored. Returning a 'bits' key is optional as not all formats have a notion of "bitdepth". Returns false on failure.
MediaHandler::getLength (   $file)

If its an audio file, return the length of the file. Otherwise 0.

File::getLength() existed for a long time, but was calling a method that only existed in some subclasses of this class (The TMH ones).

Parameters
File$file
Returns
float Length in seconds
Since
1.23
MediaHandler::getLongDesc (   $file)

Long description. Shown under image on image description page surounded by ().

Parameters
File$file
Returns
string
MediaHandler::getMetadata (   $image,
  $path 
)

Get handler-specific metadata which will be saved in the img_metadata field.

Parameters
File | FSFile$imageThe image object, or false if there isn't one. Warning, FSFile::getPropsFromPath might pass an FSFile instead of File (!)
string$pathThe filename
Returns
string A string of metadata in php serialized form (Run through serialize())
MediaHandler::getMetadataType (   $image)

Get a string describing the type of metadata, for display purposes.

Note
This method is currently unused.
Parameters
File$image
Returns
string
static MediaHandler::getMetadataVersion ( )
static

Get metadata version.

This is not used for validating metadata, this is used for the api when returning metadata, since api content formats should stay the same over time, and so things using ForeignApiRepo can keep backwards compatibility

All core media handlers share a common version number, and extensions can use the GetMetadataVersion hook to append to the array (they should append a unique string so not to get confusing). If there was a media handler named 'foo' with metadata version 3 it might add to the end of the array the element 'foo=3'. if the core metadata version is 2, the end version string would look like '2;foo=3'.

Returns
string Version string
MediaHandler::getPageDimensions ( File  $image,
  $page 
)

Get an associative array of page dimensions Currently "width" and "height" are understood, but this might be expanded in the future. Returns false if unknown.

It is expected that handlers for paged media (e.g. DjVuHandler) will override this method so that it gives the correct results for each specific page of the file, using the $page argument.

Note
For non-paged media, use getImageSize.
Parameters
File$image
int$pageWhat page to get dimensions of
Returns
array|bool
static MediaHandler::getPageRangesByDimensions (   $pagesByDimensions)
static

Converts a dimensions array about a potentially multipage document from an exhaustive list of ordered page numbers to a list of page ranges

Parameters
Array$pagesByDimensions
Returns
String
Since
1.30
MediaHandler::getPageText ( File  $image,
  $page 
)

Generic getter for text layer. Currently overloaded by PDF and DjVu handlers

Parameters
File$image
int$pagePage number to get information for
Returns
bool|string Page text or false when no text found or if unsupported.
MediaHandler::getParamMap ( )
abstract

Get an associative array mapping magic word IDs to parameter names. Will be used by the parser to identify parameters.

MediaHandler::getRotation (   $file)

On supporting image formats, try to read out the low-level orientation of the file and return the angle that the file needs to be rotated to be viewed.

This information is only useful when manipulating the original file; the width and height we normally work with is logical, and will match any produced output views.

For files we don't know, we return 0.

Parameters
File$file
Returns
int 0, 90, 180 or 270
MediaHandler::getScriptedTransform (   $image,
  $script,
  $params 
)

Get a MediaTransformOutput object representing an alternate of the transformed output which will call an intermediary thumbnail assist script.

Used when the repository has a thumbnailScriptUrl option configured.

Return false to fall back to the regular getTransform().

Parameters
File$image
string$script
array$params
Returns
bool|ThumbnailImage
MediaHandler::getShortDesc (   $file)

Short description. Shown on Special:Search results.

Parameters
File$file
Returns
string
MediaHandler::getStreamHeaders (   $metadata)
Deprecated:
since 1.30, use MediaHandler::getContentHeaders instead
Parameters
array$metadata
Returns
array
MediaHandler::getThumbType (   $ext,
  $mime,
  $params = null 
)

Get the thumbnail extension and MIME type for a given source MIME type

Parameters
string$extExtension of original file
string$mimeMIME type of original file
array$paramsHandler specific rendering parameters
Returns
array Thumbnail extension and MIME type
MediaHandler::getTransform (   $image,
  $dstPath,
  $dstUrl,
  $params 
)
final

Get a MediaTransformOutput object representing the transformed output. Does not actually do the transform.

Parameters
File$image
string$dstPathFilesystem destination path
string$dstUrlDestination URL to use in output HTML
array$paramsArbitrary set of parameters validated by $this->validateParam()
Returns
MediaTransformOutput
MediaHandler::getWarningConfig (   $file)

Gets configuration for the file warning message. Return value of the following structure: [ // Required, module with messages loaded for the client 'module' => 'example.filewarning.messages', // Required, array of names of messages 'messages' => [ // Required, main warning message 'main' => 'example-filewarning-main', // Optional, header for warning dialog 'header' => 'example-filewarning-header', // Optional, footer for warning dialog 'footer' => 'example-filewarning-footer', // Optional, text for more-information link (see below) 'info' => 'example-filewarning-info', ], // Optional, link for more information 'link' => 'http://example.com', ]

Returns null if no warning is necessary.

Parameters
File$file
Returns
array|null
MediaHandler::isAnimatedImage (   $file)

The material is an image, and is animated. In particular, video material need not return true.

Note
Before 1.20, this was a method of ImageHandler only
Parameters
File$file
Returns
bool
MediaHandler::isEnabled ( )

False if the handler is disabled for all files

Returns
bool
MediaHandler::isExpensiveToThumbnail (   $file)

True if creating thumbnails from the file is large or otherwise resource-intensive.

Parameters
File$file
Returns
bool
MediaHandler::isMetadataValid (   $image,
  $metadata 
)

Check if the metadata string is valid for this handler. If it returns MediaHandler::METADATA_BAD (or false), Image will reload the metadata from the file and update the database. MediaHandler::METADATA_GOOD for if the metadata is a-ok, MediaHandler::METADATA_COMPATIBLE if metadata is old but backwards compatible (which may or may not trigger a metadata reload).

Note
Returning self::METADATA_BAD will trigger a metadata reload from file on page view. Always returning this from a broken file, or suddenly triggering as bad metadata for a large number of files can cause performance problems.
Parameters
File$image
string$metadataThe metadata in serialized form
Returns
bool
MediaHandler::isMultiPage (   $file)

True if the type has multi-page capabilities

Parameters
File$file
Returns
bool
MediaHandler::isVectorized (   $file)

The material is vectorized and thus scaling is lossless

Parameters
File$file
Returns
bool
MediaHandler::logErrorForExternalProcess (   $retval,
  $err,
  $cmd 
)
protected

Log an error that occurred in an external process

Moved from BitmapHandler to MediaHandler with MediaWiki 1.23

Since
1.23
Parameters
int$retval
string$errError reported by command. Anything longer than MediaHandler::MAX_ERR_LOG_SIZE is stripped off.
string$cmd
MediaHandler::makeParamString (   $params)
abstract

Merge a parameter array into a string appropriate for inclusion in filenames

Parameters
array$paramsArray of parameters that have been through normaliseParams.
Returns
string
MediaHandler::mustRender (   $file)

True if handled types cannot be displayed directly in a browser but can be rendered

Parameters
File$file
Returns
bool
MediaHandler::normaliseParams (   $image,
$params 
)
abstract

Changes the parameter array as necessary, ready for transformation. Should be idempotent. Returns false if the parameters are unacceptable and the transform should fail

Parameters
File$image
array&$params
MediaHandler::pageCount ( File  $file)

Page count for a multi-page document, false if unsupported or unknown

Parameters
File$file
Returns
bool
MediaHandler::parseParamString (   $str)
abstract

Parse a param string made with makeParamString back into an array

Parameters
string$strThe parameter string without file name (e.g. 122px)
Returns
array|bool Array of parameters or false on failure.
MediaHandler::parserTransformHook (   $parser,
  $file 
)

Modify the parser object post-transform.

This is often used to do $parser->addOutputHook(), in order to add some javascript to render a viewer. See TimedMediaHandler or OggHandler for an example.

Parameters
Parser$parser
File$file
MediaHandler::removeBadFile (   $dstPath,
  $retval = 0 
)

Check for zero-sized thumbnails. These can be generated when no disk space is available or some other error occurs

Parameters
string$dstPathThe location of the suspect file
int$retvalReturn value of some shell process, file will be deleted if this is non-zero
Returns
bool True if removed, false otherwise
MediaHandler::sanitizeParamsForBucketing (   $params)

Returns a normalised params array for which parameters have been cleaned up for bucketing purposes

Parameters
array$params
Returns
array
MediaHandler::supportsBucketing ( )

Returns whether or not this handler supports the chained generation of thumbnails according to buckets

Returns
bool
Since
1.24
MediaHandler::validateParam (   $name,
  $value 
)
abstract

Validate a thumbnail parameter at parse time. Return true to accept the parameter, and false to reject it. If you return false, the parser will do something quiet and forgiving.

Parameters
string$name
mixed$value
MediaHandler::verifyUpload (   $fileName)

File validation hook called on upload.

If the file at the given local path is not valid, or its MIME type does not match the handler class, a Status object should be returned containing relevant errors.

Parameters
string$fileNameThe local path to the file.
Returns
Status
MediaHandler::visibleMetadataFields ( )
protected

Get a list of metadata items which should be displayed when the metadata table is collapsed.

Returns
array Array of strings

Member Data Documentation

const MediaHandler::MAX_ERR_LOG_SIZE = 65535

Max length of error logged by logErrorForExternalProcess()


The documentation for this class was generated from the following file: