README

The MediaPlayer app adds a video playlist feature to the Datapool web application. The app is added as a web page within the category Apps of Datapool. It allows the user to create play lists and to play videos in a loop. The user can access all browser features available for playing videos such as full screen, picture-in-picture etc.

The MediaPlayer app was the first app which implemented the Datapool App interface, and in a way this was the motivation for creating this app.

The user interface (web page)

After a playlist has been created whithin the selected Group and Folder it can be played in a loop in descending or ascending order. Clicking one of the two play buttons buttons below the player will start the loop. The direction is descending by clicking the left button and ascending by clicking the right button.

Videos can be skipped by clicking the same play button again.

How does it work?

Datapool stores video meta data as entry in the database table multimedia. The video files themself are stored in the filespace folder and linked to the database entry by the EntryId. Any video entry located in table multimedia can be linked to a MediaPlayer playlist entry, i.e. the playlist entry stores only the link. The available videos are displayed as a drop down list from which they can be selected.

Playlists are organised within Groups and Folders. Technically a playlist is a collection of entries within the same Group and Folder with each playlist entry pointing to a video entry.

Everything at Datapool is based on entries (multi-dimensional arrays) with a common structure of the first level array keys Source, Group, Folder, Name, EntryId etc. The value of entry['Source'] is equal to the database table name, the other keys are equal to the database column names.

While the web page is loading, all videos of the selected playlist are copied into the www-temporary-directory. The corresponding file names with locations are presented on the webpage as href-attributes of hidden a-tags. Inline javascript collects all file names with locations from the a-tags and loads the first file into the src-tag of the video player. When a video is finished, a new video is loaded into the player.

Background information

The class MediaPlayer.php is instantiated by Datapool's SourcePot\DatapoolRoot-class. When the Datapool web application is loaded into the web browser and if the MediaPlayer-app is selected, SourcePot\DatapoolRoot-class will call the run method of SourcePot\MediaPlayer\MediaPlayer. The run method creates the html code enveloped by the web page's main-tags. The file content of MediaPlayer.js and MediaPlayer.css files is loaded into the webpage as inline css and js code. This is necessary, because these files are located in the vendor-directory rather than the www-directory of the Datapool web application.