To create traditional form based data entry it is necessary to have 'widgets' available which express the combination of reference model and archetype based constraints on the user at the time of data entry. The openEHR data types are fully described in the openEHR specifications (Data types). These pages are for documentation of widgets for these data types from the developers' point of view and that of the Graphical User Interface. It is worth noting for those new to openEHR that the idea of 'Null Flavor' (or the reason no data exists at a particular data point is expressed as an attribute of the ELEMENT class and not within the data type (which is truly NULL if not populated).
The important widgets proposed include:

• A Text widget for DV_TEXT and its specialisation DV_CODED_TEXT which, combined with DV_PARAGRAPH, handle all textural data in openEHR
• Widgets for The Quantity data types (UML) which are comparible, have normal ranges and may exist as types of DV_INTERVAL including:
  • A [Quantity widget] for DV_QUANTITY which handles real numbers to various levels of precision and units
  • An [Integer widget] for DV_COUNT which handles integer values
  • An [Ordinal widget] for DV_ORDINAL which handles text values which are associated with an integer, and
  • A [Proportion widget] for DV_PROPORTION which handles ratios and fractions
  • The special types for handling time (UML) including:
    • A [Duration widget] for DV_DURATION for time periods
    • A [DateTime widget] for
      • DV_DATE for dates
      • DV_TIME for times, and
      • DV_DATE_TIME for dates and times
• A [True or false widget] for DV_BOOLEAN for true/false
• An [Identifier widget] for DV_IDENTIFIER for handling IDs and other identifiers
• Encapsulated data types (UML) including:
  • A [Multimedia widget] for DV_MULTIMEDIA which handles MIME types such as images
  • A [Parse widget] for DV_PARSABLE which handles information that conforms to known formal specifications such as workflow engines
• A [Hyperlink widget] for Hyperlink classes which handle expression of links to other information:
  • DV_URI which handles URIs to the web and its specialisation
    • DV_EHR_URI which provides the mechanism to address any part of an openEHR EHR (including its internet link)