Media: demo extension¶

Modules¶

The DAM system can be extended in the backend with out modules. They will be inserted and are accessable with entries in the tab menu of the main modules.

Additional database fields¶

see: dam_demo/add_fields/

Custom fields to the tx\_dam table will not only extend the table but these fields will be used automatically by the DAM in different task like indexing presets or searching.

In ext_tables.php the additional fields can be configured to be shown in the indexing preset and batch processing forms.

   // add fields to index preset fields
$TCA['tx_dam']['txdamInterface']['index_fieldList'] .= ',tx_damdemo_info,tx_damdemo_customcategory';

Indexing rule¶

see: dam_damo/indexrule/

base class: tx_dam_indexRuleBase

Do you have special files with meta data in it which needs to be processed while indexing? This can be done with own indexing rules.

Services for indexing¶

see: dam_demo/sv1/

base class: t3lib_svbase

The indexing function of the DAM currently uses three service types: metaExtract , textExtract and textLang .

For more information on services see the services documentation.

Previewer¶

see: dam_demo/previewer/

base class: tx_dam_previewerProcBase

Previewer are used to display a preview like a thumbnail or render a small gadget to see or play a file. The example below shows a simple MP3 player.

In principle several previewer types are possible. Implemented is currently a type that will be displayed in record editing view.

Actions¶

see: dam_demo/action/

base class: tx_dam_actionBase

Actions are GUI elements like icons or buttons that trigger a command for an item like a file or a record. Modules that use actions can easily be extended by own extensions.

The file module for example use three kind of actions which can be seen below.

Selection tree¶

see: dam_demo/selection/

base class: tx_dam_selBrowseTree

Selection trees provide a navigation tree and in the same time a selection class to create a SQL query from it's passed parameters. This is some kind of a misconception but for historical reason this will not be changed soon.

Selection class¶

see: dam/components/class.tx_dam_selectionStringSearch.php

base class: tx_dam_selProcBase

Selections are used to create SQL query parts depending on parameters. Pure selection classes have no GUI – in opposition to Selection trees.

tx_dam¶

Some of the data fields below are not yet used by the DAM. They will be marked as 'Not yet supported'. Their intended use in the future will be described none the less.

As with many record forms in the TYPO3 framework the backend form for the DAM record comes in a series of different field combinations dependent no the media_type of the file in question. The field description below covers every possible field even if no media_type will show all fields in one form.

SELECT¶

OR¶

AND¶

NOT¶

SEARCH¶

DESELECT_ID¶

The second key defines a registered selection class.

The third key is defined by the selection tree itself and will be passed to the selection class to generate a SQL query part.

2. In the module base class tx_damSCbase the selection compiler class will be initialized. Following function detects the parameter array and merge it with the selection data from the user session.

tx_dam_selection::initSelection_getStored_mergeSubmitted()

3. The selection compiler is used to call for the parameters the right registered selection or selection tree class.

4. The selection class generates a small SQL query part depending on the passed parameters and the used selection type like SELECT or NOT.

5. In the module base class tx_damSCbase the compiled SQL query parts will be handed over to the query generator class tx_dam_querygen.

6. The query generator is ready to be used in modules to create the final SQL query. If wanted the query can be modified in beforehand with a count() statement for example.

metaExtract¶

The metaExtract service is used to extract meta information form input files. For a functional implementation see the extensions cc_metaexif or cc_metaexec.

if (!is_object($serviceObj = t3lib_div::makeInstanceService('metaExtract',$fileType))) {
  $serviceObj = t3lib_div::makeInstanceService('metaExtract',$meta['fields']['media_type'].':*');
}

if (is_object($serviceObj)) {
  $serviceObj->setInputFile($absFile,$fileType);
       if ($serviceObj->process('','',array('meta'=>$meta))>0 AND (is_array($svmeta = $serviceObj->getOutput()))) {
        $meta = t3lib_div::array_merge_recursive_overrule($meta,$svmeta);
}
  $serviceObj->__destruct();
  unset($serviceObj);
}

textExtract¶

The textExtract service is used to extract text samples from text documents. In the context of the DAM the results of the service will be used to fill the fields 'search_content' and 'abstract' of the DAM record.For a functional implementation see the extensions cc_txtextexec or cc_txtextphp.

The textExtract service follows the same basic rules as the metaExtract service. Its relevance for specific file types is defined by subtypes. Defining a more general scope for a textExtract service by giving a media type as subtype ('text:*') is not possible in the DAM indexing context.

The input file of the service is once again defined by the function setInputFile().

The actual textinformation must be retrieved by the functino process() which again is the only function necessary in the specific service class. Other than in the metaExtract service the function process() need not return TRUE in order for the operation to go through.

As the extracted text is transferred by the function getOutput() again the function process() needs to save the textdata in the variable $this->out again. $this->out is no array in this context, but a text variable.

textLang¶

The textLang Service is used to detect the language of a text content. The detected language will be stored for files of media type text. For a functional implementation see the extensions cc_langguess or cc_textcat.

((generated))¶

$GLOBALS['SOBE']->debugContent['mykey'] = '<h4>My data</h4>'.t3lib_div::view_array($mydata);