net.sf.click.control
Class Field

java.lang.Object
  net.sf.click.control.AbstractControl
      net.sf.click.control.Field

All Implemented Interfaces:

Control, Serializable

Direct Known Subclasses:

Button, Checkbox, FieldSet, FileField, HiddenField, Label, Radio, RadioGroup, Select, TextArea, TextField

public abstract class Field

extends AbstractControl

Provides an abstract form Field control. Field controls are contained by the Form control which will orchestrate the processing and rendering of the contained fields. All Form field controls must extend this abstract class.

Field Processing

Post Requests

When processing POST requests forms typically invoke the onProcess() method on all its fields. The Field onProcess() method is used to bind the fields request value, validate the submission and invoke any control listener method. If the onProcess() method returns true the form will continue processing fields, otherwise the form will abort further processing.

The body of the Field onProcess() method is detailed below.

 public boolean onProcess() {
     bindRequestValue();

     if (getValidate()) {
         validate();
     }

     registerActionEvent();

     return true;
 } 

The Field methods called by onProcess() include:

bindRequestValue()

This method will bind the HTTP request value to the Field's value.

getValidate()

This method will return true if the Field should validate itself. This value is generally inherited from the parent Form, however the Field can override this value and specify whether it should be validated.

validate()

This method will validate the submitted Field value. If the submitted value is not valid this method should set the Field error property, which can be rendered by the Form.

AbstractControl.registerActionEvent()

This method will register any Control action listener method which has be defined for the Field.

Field subclasses generally only have to override the validate() method, and possibly the bindRequestValue() method, to provide their own behaviour.

Get Requests

When processing GET requests a Page's Form will typically perform no processing and simply render itself and its Fields.

Rendering

Field subclasses must override the Object.toString() method to enable themselves to be rendered as HTML. With the increasing use of AJAX, Fields should render themselves as valid XHTML, so that they may be parsed correctly and used as the innerHtml in the DOM.

When a Form object renders a Field using autolayout, it renders the Field in a table row using the Field's label attribute, its error attribute if defined, and the Fields toString() method.

To assist with rendering valid HTML Field subclasses can use the HtmlStringBuffer class.

Message Resources

Fields support a hierarchy of resource bundles for displaying validation error messages and display messages. These localized messages can be accessed through the methods:

• AbstractControl.getMessage(String)
• AbstractControl.getMessage(String, Object)
• AbstractControl.getMessage(String, Object[])
• AbstractControl.getMessages()
• setErrorMessage(String)
• setErrorMessage(String, Object)

The order in which localized messages resolve are:

Page scope messages

Message lookups are first resolved to the Pages message bundle if it exists. For example a Login page may define the message properties:

 /com/mycorp/page/Login.properties 

If you want messages to be used only for a specific Page, this is where to place them.

Global page scope messages

Next message lookups are resolved to the global pages message bundle if it exists.

 /click-page.properties 

If you want messages to be used across your entire application this is where to place them.

Control scope messages

Next message lookups are resolved to the Control message bundle if it exists. For example a CustomTextField control may define the message properties:

 /com/mycorp/control/CustomTextField.properties 

Global control scope messages

Finally message lookups are resolved to the global application control message bundle if the message has not already found. The global control properties file is:

 /click-control.properties 

You can modify these properties by copying this file into your applications root class path and editing these properties.

Note when customizing the message properties you must include all the properties, not just the ones you want to override.

Author:

Malcolm Edgar

See Also:

Serialized Form

Field Summary

protected boolean	disabled The Field disabled value.
protected String	error The Field error message.
protected boolean	focus The request focus flag.
protected Form	form The parent Form.
protected String	help The Field help text.
protected String	label The Field label.
protected boolean	readonly The Field is readonly flag.
protected boolean	required The Field is required flag.
protected int	tabindex The Field 'tabindex' attribute.
protected String	title The Field 'title' attribute, which acts as a tooltip help message.
protected Boolean	validate The validate Field value onProcess() invokation flag.
protected String	value The Field value.

Fields inherited from class net.sf.click.control.AbstractControl

actionListener, attributes, listener, listenerMethod, messages, name, parent, styles

Fields inherited from interface net.sf.click.Control

CONTROL_MESSAGES

Constructor Summary

Field()
Construct a new Field object.

Field(String name)
Construct the Field with the given name.

Field(String name, String label)
Construct the Field with the given name and label.

Method Summary

void	bindRequestValue() This method binds the submitted request value to the Field's value.
String	getError() Return the validation error message if the Field is not valid, or null if valid.
protected String	getErrorLabel() Return a normalized label for display in error messages.
boolean	getFocus() Return true if the field has requested focus.
String	getFocusJavaScript() Return the Field focus JavaScript.
Form	getForm() Return the parent Form containing the Field or null if no form is present in the parent hierarchy.
String	getHelp() Return the field help text.
String	getId() Return the Form and Field id appended: "form-field" Use the field the "id" attribute value if defined, or the name otherwise.
String	getLabel() Return the field display label.
protected String	getRequestValue() Return the field's value from the request.
int	getTabIndex() Return the field "tabindex" attribute value.
String	getTextAlign() Return the field CSS "text-align" style, or null if not defined.
String	getTitle() Return the 'title' attribute, or null if not defined.
boolean	getValidate() Return true if the Field should validate itself when being processed.
String	getValidationJavaScript() Return the field JavaScript client side validation function.
String	getValue() Return the Field value.
Object	getValueObject() Return the object representation of the Field value.
String	getWidth() Return the width CSS "width" style, or null if not defined.
boolean	isDisabled() Return true if the Field is disabled.
boolean	isHidden() Return true if the Field type is hidden (<input type="hidden"/>) or false otherwise.
boolean	isReadonly() Return true if the Field is a readonly.
boolean	isRequired() Return true if the Field's value is required.
boolean	isValid() Return true if the Field is valid after being processed, or false otherwise.
void	onInit() This method does nothing.
boolean	onProcess() This method processes the page request returning true to continue processing or false otherwise.
void	setDisabled(boolean disabled) Set the Field disabled flag.
void	setError(String error) Set the Field validation error message.
protected void	setErrorMessage(String key) Set the error with the a label formatted message specified by the given message bundle key.
protected void	setErrorMessage(String key, double value) Set the error with the a label and value formatted message specified by the given message bundle key.
protected void	setErrorMessage(String key, int value) Set the error with the a label and value formatted message specified by the given message bundle key.
protected void	setErrorMessage(String key, Object value) Set the error with the a label and value formatted message specified by the given message bundle key.
void	setFocus(boolean focus) Set the Field request focus flag.
void	setForm(Form form) Set the Field's the parent Form.
void	setHelp(String help) Set the Field help text.
void	setLabel(String label) Set the Field display caption.
void	setListener(Object listener, String method) The callback listener will only be called during processing if the Field value is valid.
void	setParent(Object parent) Set the parent of the Field.
void	setReadonly(boolean readonly) Set the Field readonly flag.
void	setRequired(boolean required) Set the Field required status.
void	setTabIndex(int tabindex) Set the field "tabindex" attribute value.
void	setTextAlign(String align) Set the field CSS horizontal "text-align" style.
void	setTitle(String value) Set the 'title' attribute tooltip message.
void	setValidate(boolean validate) Set the validate Field value when being processed flag.
void	setValue(String value) Set the Field value.
void	setValueObject(Object object) Set the value of the field using the given object.
void	setWidth(String value) Set the the CSS "width" style attribute.
void	validate() The validate method is invoked by onProcess() to validate the request submission.

Methods inherited from class net.sf.click.control.AbstractControl

addStyleClass, appendAttributes, getActionListener, getAttribute, getAttributes, getContext, getControlSizeEst, getHtmlImports, getMessage, getMessage, getMessage, getMessages, getName, getPage, getParent, getStyle, getStyles, getTag, hasAttribute, hasAttributes, hasStyles, onDeploy, onDestroy, onRender, registerActionEvent, removeStyleClass, render, renderTagBegin, renderTagEnd, setActionListener, setAttribute, setId, setName, setStyle, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

disabled

protected boolean disabled

The Field disabled value.

error

protected String error

The Field error message.

focus

protected boolean focus

The request focus flag.

form

protected Form form

The parent Form.

help

protected String help

The Field help text.

label

protected String label

The Field label.

readonly

protected boolean readonly

The Field is readonly flag.

required

protected boolean required

The Field is required flag.

tabindex

protected int tabindex

The Field 'tabindex' attribute.

title

protected String title

The Field 'title' attribute, which acts as a tooltip help message.

validate

protected Boolean validate

The validate Field value onProcess() invokation flag.

value

protected String value

The Field value.

Constructor Detail

Field

public Field()

Construct a new Field object.

Field

public Field(String name)

Construct the Field with the given name.

Parameters:

name - the name of the Field

Field

public Field(String name,
             String label)

Construct the Field with the given name and label.

Parameters:

name - the name of the Field

label - the label of the Field

Method Detail

setParent

public void setParent(Object parent)

Set the parent of the Field.

Specified by:

setParent in interface Control

Overrides:

setParent in class AbstractControl

Parameters:

parent - the parent of the Control

Throws:

IllegalStateException - if AbstractControl.name is not defined

IllegalArgumentException - if the given parent instance is referencing this object: if (parent == this)

See Also:

Control.setParent(Object)

isDisabled

public boolean isDisabled()

Return true if the Field is disabled. The Field will also be disabled if the parent FieldSet or Form is disabled.

Important Note: disabled fields will not submit their values in a HTML form POST. This may cause validation issues in a form submission. Please note this is a HTML limitation and is not due to Click.

Returns:

true if the Field is disabled

setDisabled

public void setDisabled(boolean disabled)

Set the Field disabled flag.

Important Note: disabled fields will not submit their values in a HTML form POST. This may cause validation issues in a form submission. Please note this is a HTML limitation and is not due to Click.

Parameters:

disabled - the Field disabled flag

getError

public String getError()

Return the validation error message if the Field is not valid, or null if valid.

Returns:

the Field validation error message, or null if valid

setError

public void setError(String error)

Set the Field validation error message. If the error message is not null the Field is invalid, otherwise it is valid.

Parameters:

error - the validation error message

getFocus

public boolean getFocus()

Return true if the field has requested focus.

Returns:

true if the field has requested focus

setFocus

public void setFocus(boolean focus)

Set the Field request focus flag.

Parameters:

focus - the request focus flag

getFocusJavaScript

public String getFocusJavaScript()

Return the Field focus JavaScript.

Returns:

the Field focus JavaScript

getForm

public Form getForm()

Return the parent Form containing the Field or null if no form is present in the parent hierarchy.

Returns:

the parent Form containing the Field

setForm

public void setForm(Form form)

Set the Field's the parent Form.

Parameters:

form - Field's parent Form

getHelp

public String getHelp()

Return the field help text.

If the help value is null, this method will attempt to find a localized help message in the parent messages using the key:

getName() + ".help"

If not found then the message will be looked up in the /click-control.properties file using the same key.

For examle given a CustomerPage with the properties file CustomerPage.properties:

 name.label=Customer Name
 name.help=Full name or Business name 

The page TextField code:

 public class CustomerPage extends Page {
     TextField nameField = new TextField("name");
     ..
 } 

Will render the TextField label and title properties as:

 <td><label>Customer Name</label></td>
 <td><input type="text" name="name"/> <span="Full name or Business name"/>/td> 

How the help text is rendered is depends upon the Field subclass.

Returns:

the help text of the Field

setHelp

public void setHelp(String help)

Set the Field help text.

Parameters:

help - the help text of the Field

isHidden

public boolean isHidden()

Return true if the Field type is hidden (<input type="hidden"/>) or false otherwise. By default this method returns false.

Returns:

false

getId

public String getId()

Return the Form and Field id appended: "form-field"

Use the field the "id" attribute value if defined, or the name otherwise.

Specified by:

getId in interface Control

Overrides:

getId in class AbstractControl

Returns:

HTML element identifier attribute "id" value

See Also:

Control.getId()

getLabel

public String getLabel()

Return the field display label.

If the label value is null, this method will attempt to find a localized label message in the parent messages using the key:

getName() + ".label"

If not found then the message will be looked up in the /click-control.properties file using the same key. If a value is still not found, the Field name will be converted into a label using the method: ClickUtils.toLabel(String)

For example given a CustomerPage with the properties file CustomerPage.properties:

 name.label=Customer Name
 name.title=Full name or Business name 

The page TextField code:

 public class CustomerPage extends Page {
     TextField nameField = new TextField("name");
     ..
 } 

Will render the TextField label and title properties as:

 <td><label>Customer Name</label></td>
 <td><input type="text" name="name" title="Full name or Business name"/></td> 

When a label value is not set, or defined in any properties files, then its value will be created from the Fields name.

For example given the TextField code:

 TextField nameField = new TextField("faxNumber");  

Will render the TextField label as:

 <td><label>Fax Number</label></td>
 <td><input type="text" name="faxNumber"/></td> 

Returns:

the display label of the Field

setLabel

public void setLabel(String label)

Set the Field display caption.

Parameters:

label - the display label of the Field

setListener

public void setListener(Object listener,
                        String method)

The callback listener will only be called during processing if the Field value is valid. If the field has validation errors the listener will not be called.

Specified by:

setListener in interface Control

Overrides:

setListener in class AbstractControl

Parameters:

listener - the listener object with the named method to invoke

method - the name of the method to invoke

See Also:

Control.getName()

isReadonly

public boolean isReadonly()

Return true if the Field is a readonly. The Field will also be readonly if the parent FieldSet or Form is readonly.

Returns:

true if the Field is a readonly

setReadonly

public void setReadonly(boolean readonly)

Set the Field readonly flag.

Parameters:

readonly - the Field readonly flag

isRequired

public boolean isRequired()

Return true if the Field's value is required.

Returns:

true if the Field's value is required

setRequired

public void setRequired(boolean required)

Set the Field required status.

Parameters:

required - set the Field required status

getTabIndex

public int getTabIndex()

Return the field "tabindex" attribute value.

Returns:

the field "tabindex" attribute value

setTabIndex

public void setTabIndex(int tabindex)

Set the field "tabindex" attribute value.

Parameters:

tabindex - the field "tabindex" attribute value

getTextAlign

public String getTextAlign()

Return the field CSS "text-align" style, or null if not defined.

Returns:

the field CSS "text-align" style, or null if not defined.

setTextAlign

public void setTextAlign(String align)

Set the field CSS horizontal "text-align" style.

Parameters:

align - the CSS "text-align" value: ["left", "right", "center"]

getTitle

public String getTitle()

Return the 'title' attribute, or null if not defined. The title attribute acts like tooltip message over the Field.

If the title value is null, this method will attempt to find a localized label message in the parent messages using the key:

getName() + ".title"

If not found then the message will be looked up in the /click-control.properties file using the same key. If still not found the title will be left as null and will not be rendered.

For examle given a CustomerPage with the properties file CustomerPage.properties:

 name.label=Customer Name
 name.title=Full name or Business name 

The page TextField code:

 public class CustomerPage extends Page {
     TextField nameField = new TextField("name");
     ..
 } 

Will render the TextField label and title properties as:

 <td><label>Customer Name</label></td>
 <td><input type="text" name="name" title="Full name or Business name"/></td> 

Returns:

the 'title' attribute tooltip message

setTitle

public void setTitle(String value)

Set the 'title' attribute tooltip message.

Parameters:

value - the 'title' attribute tooltip message

getValidate

public boolean getValidate()

Return true if the Field should validate itself when being processed.

If the validate attribute for the Field is not explicity set, this method will return the validation status of its parent Form, see Form.getValidate(). If the Field validate attribute is not set and the parent Form is not set this method will return true.

This method is called by the onProcess() method to determine whether the the Field validate() method should be invoked.

Returns:

true if the Field should validate itself when being processed.

setValidate

public void setValidate(boolean validate)

Set the validate Field value when being processed flag.

Parameters:

validate - the field value when processed

getValidationJavaScript

public String getValidationJavaScript()

Return the field JavaScript client side validation function.

The function name must follow the format validate_[id], where the id is the DOM element id of the fields focusable HTML element, to ensure the function has a unique name.

Returns:

the field JavaScript client side validation function

isValid

public boolean isValid()

Return true if the Field is valid after being processed, or false otherwise. If the Field has no error message after Control.onProcess() has been invoked it is considered to be valid.

Returns:

true if the Field is valid after being processed

getValue

public String getValue()

Return the Field value.

Returns:

the Field value

setValue

public void setValue(String value)

Set the Field value.

Parameters:

value - the Field value

getValueObject

public Object getValueObject()

Return the object representation of the Field value. This method will return a string value, or null if the string value is null or is zero length.

Specialized object field subclasses should override this method to return a non string object. For examples a DoubleField would return a Double value instead.

Returns:

the object representation of the Field value

setValueObject

public void setValueObject(Object object)

Set the value of the field using the given object.

Parameters:

object - the object value to set

getWidth

public String getWidth()

Return the width CSS "width" style, or null if not defined.

Returns:

the CSS "width" style attribute, or null if not defined

setWidth

public void setWidth(String value)

Set the the CSS "width" style attribute.

Parameters:

value - the CSS "width" style attribute

bindRequestValue

public void bindRequestValue()

This method binds the submitted request value to the Field's value.

onInit

public void onInit()

This method does nothing. Subclasses may override this method to perform additional initialization.

Specified by:

onInit in interface Control

Overrides:

onInit in class AbstractControl

See Also:

Control.onInit()

onProcess

public boolean onProcess()

This method processes the page request returning true to continue processing or false otherwise. The Field onProcess() method is typically invoked by the Form onProcess() method when processing POST request.

This method will bind the Field request parameter value to the field, validate the submission and invoke its callback listener if defined. The code of this method is provided below:

 public boolean onProcess() {
     bindRequestValue();

     if (getValidate()) {
         validate();
     }

     registerActionEvent();

     return true
 } 

Specified by:

onProcess in interface Control

Overrides:

onProcess in class AbstractControl

Returns:

true to continue Page event processing or false otherwise

See Also:

Control.onProcess()

validate

public void validate()

The validate method is invoked by onProcess() to validate the request submission. Field subclasses should override this method to implement request validation logic.

If the field determines that the submission is invalid it should set error property with the error message.

getErrorLabel

protected String getErrorLabel()

Return a normalized label for display in error messages.

The error label is a normalized version of getLabel().

Returns:

a normalized label for error message display

setErrorMessage

protected void setErrorMessage(String key)

Set the error with the a label formatted message specified by the given message bundle key. The message will be formatted with the field label using getErrorLabel().

setErrorMessage will attempt to find a localized error message as described here, using the following lookup strategy:

• an error message is looked up for a specific Field instance by prefixing the key with the Field's name:

  getMessage(getName() + "." + key);

• if no message is found for a specific Field instance, an error message is looked up for the Field class based on the key:

  getMessage(key);

Parameters:

key - the key of the localized message bundle string

setErrorMessage

protected void setErrorMessage(String key,
                               Object value)

Set the error with the a label and value formatted message specified by the given message bundle key. The message will be formatted with the field label {0} using getErrorLabel() and the given value {1}.

Also see setErrorMessage(java.lang.String) on how to specify error messages for specific Field instances.

Parameters:

key - the key of the localized message bundle string

value - the value to format in the message

setErrorMessage

protected void setErrorMessage(String key,
                               int value)

Set the error with the a label and value formatted message specified by the given message bundle key. The message will be formatted with the field label {0} using getErrorLabel() and the given value {1}.

Also see setErrorMessage(java.lang.String) on how to specify error messages for specific Field instances.

Parameters:

key - the key of the localized message bundle string

value - the value to format in the message

setErrorMessage

protected void setErrorMessage(String key,
                               double value)

Set the error with the a label and value formatted message specified by the given message bundle key. The message will be formatted with the field label {0} using getErrorLabel() and the given value {1}.

Also see setErrorMessage(java.lang.String) on how to specify error messages for specific Field instances.

Parameters:

key - the key of the localized message bundle string

value - the value to format in the message

getRequestValue

protected String getRequestValue()

Return the field's value from the request.

Returns:

the field's value from the request