package pl.caltha.forms.internal;
   
   import java.util.HashMap;
   
   import org.objectledge.parameters.Parameters;
   
   import pl.caltha.forms.ConstructionException;
   import pl.caltha.forms.Form;
   import pl.caltha.forms.FormsService;
  import pl.caltha.forms.internal.model.Bind;
  import pl.caltha.forms.internal.model.DefaultInstance;
  import pl.caltha.forms.internal.model.InstanceImpl;
  import pl.caltha.forms.internal.model.SubmitInfo;
  import pl.caltha.forms.internal.ui.UI;
  import pl.caltha.forms.internal.ui.UIConstants;
  import pl.caltha.services.xml.XMLService;
  
  /***
   * Represents Form definition.
   *
   * @author <a href="mailto:zwierzem@ngo.pl">Damian Gajda</a>
   * @version $Id: FormImpl.java,v 1.3 2005/02/08 20:33:27 rafal Exp $
   */
  public class FormImpl implements Form
  {
      /*** FormsService. */
      private FormsService formToolService;
  
      /*** XMLService is used to get validators. */
      private XMLService xmlService;
  
      /*** I18nService is used to localise strings. */
      //private I18nService i18nService;
  
      /*** Keeps ID for this form definition.. */
      private String id;
  
      /*** Keeps URI for form definition.. */
      private String definitionURI;
  
      /*** Keeps model/bind elements. */
      private HashMap bindElements = new HashMap();
  
      /*** Keeps Form's SubmitInfo. */
      protected SubmitInfo submitInfo;
  
      /*** Keeps URI for UI definition.. */
      protected String uiURI;
      /*** Keeps UI object. */
      private UI ui;
  
      /*** Keeps Instance schema URI. */
      protected String instanceSchemaURI;
      /*** Keeps Instance URI. */
      protected String defaultInstanceURI;
      /*** Keeps an object representing default Instance. */
      private DefaultInstance defaultInstance;
      
      //private Parameters parameters;
  
      /*** Creates new Form */
      public FormImpl(FormsService formToolService, XMLService xmlService,
          String definitionURI, String id)
      {
          this.definitionURI = definitionURI;
          this.id = id;
          this.formToolService = formToolService;
          this.xmlService = xmlService;
      }
  
      //------------------------------------------------------------------------
      // pl.caltha.forms.Form mehods
  
      /*** Processes a user request merging it's data with an Instance object.
       * <p>Processing consists of following steps:</p>
       * <ol>
       *  <li><b>Value extraction (from the request) and application on an Instance.</b>
       *      <p>This step is first because form-tool is a server-side tool.
       *      All values must be applied before Instance is validated, or
       *      any actions, including setting values dynamically are executed
       *      (If for instance setValue action would be executed before
       *       applying values, the result of this action could be lost).
       *      </p>
       *      <p>This action triggers bind property cache clean up
       *         ({@link pl.caltha.forms.internal.model.InstanceImpl#preprocessInit()})
       *      </p>
       *      <p>This action also triggers submit requested flag clean up
       *         ({@link pl.caltha.forms.internal.model.InstanceImpl#preprocessInit()})
       *      </p>
       *      <p>This action also triggers error collector clean up
       *         ({@link pl.caltha.forms.internal.model.InstanceImpl#preprocessInit()})
       *      </p>
       *  </li>
       *  <li><b>Event extraction (from request) and dispatching.</b>
       *      <p>Event dispatching triggers actions connected to controls.
       *      These actions may also trigger another events and so on.</p>
       *      <p>TODO: Implement event - action loop protection.</p>
       *
       *      <p>Right now only two kinds of events are extracted:</p>
      *      <ol>
      *          <li><code>activate</code> - control activation,
      *          in this case button control activation.</li>
      *          <li><code>submit</code> - submit button control activation.</li>
      *      </ol>
      *  </li>
      *  <li><b>Instance validation</b>
      *      <p>In client-side XForms implementation this step should be
      *      triggered by a changed value. In server-side processing value
      *      comparison would have to be implemented to check if any of them
      *      was changed. It is not very wise to do value comparison because
      *      there will be cases in which it will be faster to do validation
      *      than to compare all values in the Instance. That's why validation
      *      is always executed.
      *      </p>
      *  </li>
      * </ol>
      */
     public void process(pl.caltha.forms.Instance inst, Parameters parameters)
     throws Exception
     {
         InstanceImpl instance = (InstanceImpl)inst;
         // 1. Apply new values
         // Apply new values dispatches:
         //  - errorCollector init
         //  - bind expression cache should be cleared (implemented below)
         //  - selectValues should be cleared (implemented in NodeSelect)
         //  - submit requested clearing
         // 1.1.1. errorCollector
         // 1.1.2 Clear bind property cache.
         // 1.1.2 Clear submit requested.
         instance.preprocessInit();
 
         // 1.2. Set new values only if there are values sent from user's browser
         // 2. dispatch events & execute actions
         //
         // SetValues and dispatchEvents is not being called
         // for the first time instance processing.
         // This avoids Select fields clearing.
         String instanceId = parameters.get(UIConstants.INSTANCE_ID_NAME,null);
         if(instanceId != null && instanceId.equals(instance.getId()))
         {
             ui.setValues(instance, parameters);
             ui.dispatchEvents(instance, parameters);
         }
 
         // 3. validate
         // 3.1. Schema validate
         instance.validate( xmlService.getDOM4JValidator() );
         // 3.2. Check if required values are inputed
             // Required fields checking is only for Programmers using Instance
             // objects!!
             // Together with submit requested it gives information on form
             // Instance being ready or not.
         boolean hasRequired = ui.hasRequired(instance);
         instance.setHasRequired(hasRequired);
     }
 
     /*** Returns ID for this form's definition file. This is a form definition URI
      * ({@link Form#getDefinitionURI}) changed to be compatible with XHTML IDs. */
     public String getId()
     {
         return id;
     }
 
     public String getDefinitionURI()
     {
         return definitionURI;
     }
 
     public String getUIDefinitionURI()
     {
         return uiURI;
     }
 
     public String getDefaultInstanceURI()
     {
         return defaultInstanceURI;
     }
 
     public String getInstanceSchemaURI()
     {
         return instanceSchemaURI;
     }
 
     //------------------------------------------------------------------------
     // Methods used during processing - runtime
 
     /*** Returns a default instance object. */
     public DefaultInstance getDefaultInstance()
     {
         return defaultInstance;
     }
 
     /*** Creates a new instance object. */
     InstanceImpl createInstance(String instanceId)
     {
         return defaultInstance.createInstance(instanceId);
     }
 
     /*** Creates a new instance object from a saved instance data. */
     InstanceImpl createInstance(String instanceId, byte[] savedState)
     throws Exception
     {
         return defaultInstance.createInstance(instanceId, savedState);
     }
 
     // methods used in UI
     public Bind getBind(String id)
     throws ConstructionException
     {
         if(bindElements.containsKey(id))
         {
             return (Bind)(bindElements.get(id));
         }
         throw new ConstructionException("Cannot find bind element with id='"+id+"'");
     }
 
     public SubmitInfo getSubmitInfo()
     {
         return submitInfo;
     }
 
     public UI getUI()
     {
         return ui;
     }
 
     public FormsService getFormToolService()
     {
         return formToolService;
     }
 
 /*    public I18nService getI18nService()
     {
         return i18nService;
     }
 */
     //------------------------------------------------------------------------
     // Form building methods
     void setDefaultInstance(DefaultInstance defaultInstance)
     {
         this.defaultInstance = defaultInstance;
     }
 
     void addBindElement(Bind bind)
     throws ConstructionException
     {
         // guard from bind elements with no id
         String id = bind.getId();
         if(id == null || id.equals(""))
         {
             throw new ConstructionException("Cannot add Bind element with no id");
         }
 
         if(!bindElements.containsKey(id))
         {
             bindElements.put(id, bind);
         }
         // duplicate ids
         else
         {
             throw new ConstructionException("Duplicate bind element id='"+id+"'");
         }
     }
 
     void init(UI ui)
     throws ConstructionException
     {
         this.ui = ui;
     }
 }