• Created by Unknown User (don), last modified on 15-07-2008

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Gui components

DelftShell is slowly starting to take a new shape. We're currently busy implementing blocking functionality required for:

  • Network Editor
  • Cross-section Editor
  • Time series Editor

See a couple of screenshots below to get an idea about direction of current development.

These still a lot of cosmetic changes

Persistency

One of the source of pain in the application for developers is persistancy / data access. But thanks to NHibernate it is simplified a lot, so that mapping network or time series to a database, which is currently used as a file format of a DeltShell, seems to be a relatively easy task. Actually if classes are implemented correctly, which means:

  • id field of long type is present
  • relations to other entities are well-defined
  • relations to collections use only interfaces such as IList<>, ICollection<>
  • value objects do not contain any manipulation logic such as generating data when properties are set

In this case adding mapping file as a *.hbm.xml file embedded into assembly seems to be sufficient to write/read data from a database.

We still should think about backward-compatibility of a file format. Probably use of some classes providing upgrade strategy from version to version will be sufficient.

In some exceptional cases we need to make implementation of own persistent types, e.g. mapping Geometry to database or some types such as Brush, Pen. See example here: Composite types in NHibernate.

Here how mapping of a TimeSeries / Function classes looks like. Note that currently we use DataTable-based value store for a Function which is mapped to a database using custom type which simply calls FromXml / ToXml for a DataTable. As result we're getting all data of one time series embedded into a text field. In the future it probably will be NetCDF-based store when a lot of results will be produced by a model.

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping>
  <class name="DelftTools.DataObjects.Functions.Function, DelftTools.DataObjects" 
   table="function" lazy="false" discriminator-value="function">
    <id name="Id" column="id" type="Int64" unsaved-value="0" access="nosetter.camelcase">
      <generator class="native" />
    </id>
    <discriminator column="type" type="string"/>

    <property name="Name" column="name" />

    <list name="Arguments" cascade="all-delete-orphan" table="function_arguments">
      <key column="function_id"/>
      <list-index base="1" column="list_index" />
      <many-to-many class="DelftTools.DataObjects.Functions.Variable, DelftTools.DataObjects"
       column="variable_id"/>
    </list>

    <list name="Components" cascade="all-delete-orphan" table="function_components">
      <key column="function_id"/>
      <list-index base="1" column="list_index" />
      <many-to-many class="DelftTools.DataObjects.Functions.Variable, DelftTools.DataObjects" 
       column="variable_id"/>
    </list>

    <property name="Values" 
     type="DelftShell.Plugins.Data.NHibernate.DelftTools.Core.Dao.DataTableFunctionValueStoreUserType,
      DelftShell.Plugins.Data.NHibernate">
      <column name="values_xml"/>
      <column name="values_xml_schema"/>
    </property>

    <subclass name="DelftTools.DataObjects.Functions.TimeSeries, DelftTools.DataObjects" 
     discriminator-value="time_series" lazy="false" />
  </class>

  <class name="DelftTools.DataObjects.Functions.Variable, DelftTools.DataObjects" 
   table="function_variables">
    <id name="Id" column="id" type="Int64" unsaved-value="0" access="property">
      <generator class="native" />
    </id>
    <discriminator column="type" type="string"/>

    <property name="Name" column="name" />
    <property name="ValueType" column="value_type" type="Type" not-null="true"/>

    <subclass name="DelftTools.DataObjects.Functions.FunctionArgument`1[System.DateTime], DelftTools.DataObjects" 
     discriminator-value="argument_date_time" />
    <subclass name="DelftTools.DataObjects.Functions.FunctionArgument`1[System.Double], DelftTools.DataObjects" 
     discriminator-value="argument_double" />
    <subclass name="DelftTools.DataObjects.Functions.FunctionComponent`1[System.Double], DelftTools.DataObjects" 
     discriminator-value="component_double" />
  </class>
</hibernate-mapping>
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