org.apache.tapestry5.corelib.components: public class: DateField

org.apache.tapestry5.corelib.components
public class: DateField [javadoc | source]

java.lang.Object
   org.apache.tapestry5.corelib.base.AbstractField
      org.apache.tapestry5.corelib.components.DateField

All Implemented Interfaces:
Field

A component used to collect a provided date from the user using a client-side JavaScript calendar. Non-JavaScript clients can simply type into a text field.

One wierd aspect here is that, because client-side JavaScript formatting and parsing is so limited, we (currently) use Ajax to send the user's input to the server for parsing (before raising the popup) and formatting (after closing the popup). Wierd and inefficient, but easier than writing client-side JavaScript for that purpose.

Tapestry's DateField component is a wrapper around WebFX DatePicker.
Field Summary
static final String LOCALIZATION_CONFIGURED_FLAG Request attribute set to true if localization for the client-side DatePicker has been configured. Used to ensure that this only occurs once, regardless of how many DateFields are on the page.

Method from org.apache.tapestry5.corelib.components.DateField Summary:
beginRender, defaultFormat, defaultValidate, injectResources, isRequired, onFormat, onParse, processSubmission
Methods from org.apache.tapestry5.corelib.base.AbstractField:
afterDecorator, beforeDecorator, createDefaultParameterBinding, decorateInsideField, defaultLabel, getClientId, getControlName, getLabel, isDisabled, isRequired, processSubmission, setDecorator, setFormSupport, setup
Methods from java.lang.Object:
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Method from org.apache.tapestry5.corelib.components.DateField Detail:

void beginRender(MarkupWriter writer)
{ String value = tracker.getInput(this); if (value == null) value = formatCurrentValue(); String clientId = getClientId(); String triggerId = clientId + ":trigger"; writer.element(INPUT_PARAMETER, "type", hideTextField ? "hidden" : "text", "name", getControlName(), "id", clientId, "value", value); writeDisabled(writer); validate.render(writer); resources.renderInformalParameters(writer); decorateInsideField(); writer.end(); // Now the trigger icon. writer.element("img", "id", triggerId, "class", "t-calendar-trigger", "src", icon.toClientURL(), "alt", "[Show]"); writer.end(); // img JSONObject setup = new JSONObject(); setup.put("field", clientId); setup.put("parseURL", resources.createEventLink("parse").toAbsoluteURI()); setup.put("formatURL", resources.createEventLink("format").toAbsoluteURI()); if (request.getAttribute(LOCALIZATION_CONFIGURED_FLAG) == null) { JSONObject spec = new JSONObject(); DateFormatSymbols symbols = new DateFormatSymbols(locale); spec.put("months", new JSONArray(symbols.getMonths())); StringBuilder days = new StringBuilder(); String[] weekdays = symbols.getWeekdays(); Calendar c = Calendar.getInstance(locale); int firstDay = c.getFirstDayOfWeek(); // DatePicker needs them in order from monday to sunday. for (int i = Calendar.MONDAY; i < = Calendar.SATURDAY; i++) { days.append(weekdays[i].substring(0, 1)); } days.append(weekdays[Calendar.SUNDAY].substring(0, 1)); spec.put("days", days.toString().toLowerCase(locale)); // DatePicker expects 0 to be monday. Calendar defines SUNDAY as 1, MONDAY as 2, etc. spec.put("firstDay", firstDay == Calendar.SUNDAY ? 6 : firstDay - 2); // TODO: Skip localization if locale is English? setup.put("localization", spec); request.setAttribute(LOCALIZATION_CONFIGURED_FLAG, true); } support.addInit("dateField", setup); }
DateFormat defaultFormat()
{ DateFormat shortDateFormat = DateFormat.getDateInstance(DateFormat.SHORT, locale); if (shortDateFormat instanceof SimpleDateFormat) { SimpleDateFormat simpleDateFormat = (SimpleDateFormat) shortDateFormat; String pattern = simpleDateFormat.toPattern(); String revised = pattern.replaceAll("([^y])yy$", "$1yyyy"); return new SimpleDateFormat(revised); } return shortDateFormat; }
final Binding defaultValidate()
{ return defaultProvider.defaultValidatorBinding("value", resources); }
Computes a default value for the "validate" parameter using ComponentDefaultProvider .
void injectResources(ComponentResources resources)
{ this.resources = resources; }
public boolean isRequired()
{ return validate.isRequired(); }
JSONObject onFormat()
{ String input = request.getParameter(INPUT_PARAMETER); JSONObject response = new JSONObject(); try { long millis = Long.parseLong(input); Date date = new Date(millis); response.put(RESULT, format.format(date)); } catch (NumberFormatException ex) { response.put(ERROR, ex.getMessage()); } return response; }
Ajax event handler, used after the client-side popup completes. The client sends the date, formatted as milliseconds since the epoch, to the server, which reformats it according to the server side format and returns the result.
JSONObject onParse()
{ String input = request.getParameter(INPUT_PARAMETER); JSONObject response = new JSONObject(); try { Date date = format.parse(input); response.put(RESULT, date.getTime()); } catch (ParseException ex) { response.put(ERROR, ex.getMessage()); } return response; }
Ajax event handler, used when initiating the popup. The client sends the input value form the field to the server to parse it according to the server-side format. The response contains a "result" key of the formatted date in a format acceptable to the JavaScript Date() constructor. Alternately, an "error" key indicates the the input was not formatted correct.
protected void processSubmission(String elementName)
{ String value = request.getParameter(elementName); tracker.recordInput(this, value); Date parsedValue = null; try { if (InternalUtils.isNonBlank(value)) parsedValue = format.parse(value); } catch (ParseException ex) { tracker.recordError(this, "Date value is not parseable."); return; } try { fieldValidationSupport.validate(parsedValue, resources, validate); this.value = parsedValue; } catch (ValidationException ex) { tracker.recordError(this, ex.getMessage()); } }