Implementation of the various X-Applications tags. Includes both the actual tag implementation and abstract base classes which implement common functionality, i.e. the class FieldTag implements functionality required by its sub-classes DisplayTag and EditTag.

The content in the body of all tags must be wellformed XML. That means e.g. that every starting tag must be closed and every attribute must have its value in quotes and that tag names are case sensitive.

Here is an outline of the various tags. TODO: merge this into the tag documentation itself.

• ModuleTag implements the tag module which embraces all other X-Application tags.
• FormTag implements the tag form and is used to display or edit fields from a single document instance.
• BrowseTag implements the tag browse and is used to display and edit fields from multiple document instances which are displayed i.e. in a table.
• BrowseTag and FormTag are both derived from the abstract superclass ContainerTag.
• DisplayTag implements the display tag which can either stand by itself and displays the content of an element in the document. Or it can surround various types of input fields and then it fills the input fields with the value of the element from the document.
  i.e. <bdm:display select="/Property/Price"/> or
  <bdm:display select="/Property/Price"><input type="text" size="20"/></bdm:display>
  Input fields are disabled (readonly).
• EditTag implements the edit tag which works very similar to the DisplayTag. The difference is that input fields are enabled (writeable) and that they must always surround an input field.
  <bdm:edit select="/Property/Price"><input type="text" size="20"/></bdm:edit>
• EditTag and DisplayTag are both derived from the abstract superclass FieldTag.
• ActionTag implements the action tag which invokes an action on a certain HTML form. The action can be either to switch the single document to a certain mode i.e. create (new document), modify, delete, read or to commit a previous action with commit or cancel it with abandon. The body of the action must contain a submit button (input tag) or an anchor tag.
  i.e. <bdm:action type="modify" form="form1"><input type="submit" name="Change this document"/></bdm:action>