public DefaultCoverageStoreEditPanel(final String componentId, final Form storeEditForm) {
    super(componentId, storeEditForm);

    final IModel formModel = storeEditForm.getModel();
    // url
    TextParamPanel url =
        new TextParamPanel(
            "urlPanel", new PropertyModel(formModel, "URL"), new ResourceModel("url", "URL"), true);
    url.getFormComponent().add(new FileExistsValidator());
    add(url);
  }
  /**
   * Creates a form input component for the given datastore param based on its type and metadata
   * properties.
   *
   * @param paramMetadata
   * @return
   */
  private Panel getInputComponent(
      final String componentId, final IModel paramsModel, final ParamInfo paramMetadata) {

    final String paramName = paramMetadata.getName();
    final String paramLabel = paramMetadata.getName();
    final boolean required = paramMetadata.isRequired();
    final Class<?> binding = paramMetadata.getBinding();

    Panel parameterPanel;
    if ("dbtype".equals(paramName) || "filetype".equals(paramName)) {
      // skip the two well known discriminators
      IModel model = new MapModel(paramsModel, paramName);
      TextParamPanel tp =
          new TextParamPanel(
              componentId, model, new ResourceModel(paramLabel, paramLabel), required);
      tp.setVisible(false);
      parameterPanel = tp;
    } else if ("namespace".equals(paramName)) {
      IModel namespaceModel = new NamespaceParamModel(paramsModel, paramName);
      IModel paramLabelModel = new ResourceModel(paramLabel, paramLabel);
      parameterPanel = new NamespacePanel(componentId, namespaceModel, paramLabelModel, true);
    } else if (Boolean.class == binding) {
      // TODO Add prefix for better i18n?
      parameterPanel =
          new CheckBoxParamPanel(
              componentId,
              new MapModel(paramsModel, paramName),
              new ResourceModel(paramLabel, paramLabel));

    } else if (String.class == binding && paramMetadata.isPassword()) {
      parameterPanel =
          new PasswordParamPanel(
              componentId,
              new MapModel(paramsModel, paramName),
              new ResourceModel(paramLabel, paramLabel),
              required);
    } else {
      IModel model;
      if ("url".equalsIgnoreCase(paramName)) {
        model = new URLModel(paramsModel, paramName);
      } else {
        model = new MapModel(paramsModel, paramName);
      }

      TextParamPanel tp =
          new TextParamPanel(
              componentId, model, new ResourceModel(paramLabel, paramLabel), required);
      // if it can be a reference to the local filesystem make sure it's valid
      if (paramName.equalsIgnoreCase("url")) {
        tp.getFormComponent().add(new FileExistsValidator());
      }
      // make sure the proper value is returned, but don't set it for strings otherwise
      // we incur in a wicket bug (the empty string is not converter back to a null)
      // GR: it doesn't work for File neither.
      // AA: better not mess with files, the converters turn data dir relative to
      // absolute and bye bye data dir portability
      if (binding != null
          && !String.class.equals(binding)
          && !File.class.equals(binding)
          && !URL.class.equals(binding)) {
        tp.getFormComponent().setType(binding);
      }
      parameterPanel = tp;
    }
    return parameterPanel;
  }