org.apache.click.control
Class ActionLink

java.lang.Object
  org.apache.click.control.AbstractControl
      org.apache.click.control.AbstractLink
          org.apache.click.control.ActionLink

All Implemented Interfaces:

Serializable, Control, Stateful

public class ActionLink
extends AbstractLink

Provides a Action Link control: <a href=""></a>.

Action Link

This control can render the "href" URL attribute using getHref(), or the entire ActionLink anchor tag using AbstractControl.toString().

ActionLink support invoking control listeners.

ActionLink Example

An example of using ActionLink to call a logout method is illustrated below:

 public class MyPage extends Page {

     public MyPage() {
         ActionLink link = new ActionLink("logoutLink");
         link.setListener(this, "onLogoutClick");
         addControl(link);
     }

     public boolean onLogoutClick() {
         if (getContext().hasSession()) {
            getContext().getSession().invalidate();
         }
         setRedirect(LogoutPage.class);

         return false;
     }
 } 

The corresponding template code is below. Note href is evaluated by Velocity to getHref():

 <a href="$logoutLink.href" title="Click to Logout">Logout</a> 

ActionLink can also support a value parameter which is accessible using getValue().

For example a products table could include rows of products, each with a get product details ActionLink and add product ActionLink. The ActionLinks include the product's id as a parameter to the getHref(Object) method, which is then available when the control is processed:

 <table>
 #foreach ($product in $productList)
   <tr>
    <td>
      $product.name
    </td>
    <td>
      <a href="$detailsLink.getHref($product.id)" title="Get product information">Details</a>
    </td>
    <td>
      <a href="$addLink.getHref($product.id)" title="Add to basket">Add</a>
    </td>
   </tr>
 #end
 </table> 

The corresponding Page class for this template is:

 public class ProductsPage extends Page {

     public ActionLink addLink = new ActionLink("addLink", this, "onAddClick");
     public ActionLink detailsLink  = new ActionLink("detailsLink", this, "onDetailsClick");
     public List productList;

     public boolean onAddClick() {
         // Get the product clicked on by the user
         Integer productId = addLink.getValueInteger();
         Product product = getProductService().getProduct(productId);

         // Add product to basket
         List basket = (List) getContext().getSessionAttribute("basket");
         basket.add(product);
         getContext().setSessionAttribute("basket", basket);

         return true;
     }

     public boolean onDetailsClick() {
         // Get the product clicked on by the user
         Integer productId = detailsLink.getValueInteger();
         Product product = getProductService().getProduct(productId);

         // Store the product in the request and display in the details page
         getContext().setRequestAttribute("product", product);
         setForward(ProductDetailsPage.class);

         return false;
     }

     public void onRender() {
         // Display the list of available products
         productList = getProductService().getProducts();
     }
 } 

See also the W3C HTML reference: A Links

See Also:

AbstractLink, Submit, Serialized Form

Field Summary

static String	ACTION_LINK The action link parameter name: actionLink.
protected boolean	clicked The link is clicked.
static String	VALUE The value parameter name: value.

Fields inherited from class org.apache.click.control.AbstractLink

disabled, imageSrc, label, parameters, renderLabelAndImage, tabindex, title

Fields inherited from class org.apache.click.control.AbstractControl

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

Fields inherited from interface org.apache.click.Control

CONTROL_MESSAGES

Constructor Summary

ActionLink()
Create an ActionLink with no name defined.

ActionLink(Object listener, String method)
Create an ActionLink for the given listener object and listener method.

ActionLink(String name)
Create an ActionLink for the given name.

ActionLink(String name, Object listener, String method)
Create an ActionLink for the given name, listener object and listener method.

ActionLink(String name, String label)
Create an ActionLink for the given name and label.

ActionLink(String name, String label, Object listener, String method)
Create an ActionLink for the given name, label, listener object and listener method.

Method Summary

void	bindRequestValue() This method binds the submitted request value to the ActionLink's value.
String	getHref() Return the ActionLink anchor <a> tag href attribute value.
String	getHref(Object value) Return the ActionLink anchor <a> tag href attribute for the given value.
String	getValue() Returns the ActionLink value if the action link was processed and has a value, or null otherwise.
Double	getValueDouble() Returns the action link Double value if the action link was processed and has a value, or null otherwise.
Integer	getValueInteger() Returns the ActionLink Integer value if the ActionLink was processed and has a value, or null otherwise.
Long	getValueLong() Returns the ActionLink Long value if the ActionLink was processed and has a value, or null otherwise.
boolean	isClicked() Returns true if the ActionLink was clicked, otherwise returns false.
boolean	onProcess() This method will set the isClicked() property to true if the ActionLink was clicked, and if an action callback listener was set this will be invoked.
void	setName(String name) Set the name of the Control.
void	setParent(Object parent) Set the parent of the ActionLink.
void	setValue(String value) Set the ActionLink value.
void	setValueObject(Object object) Set the value of the ActionLink using the given object.

Methods inherited from class org.apache.click.control.AbstractLink

bindRequestParameters, defineParameter, getId, getImageSrc, getLabel, getParameter, getParameters, getParameterValues, getState, getTabIndex, getTag, getTitle, hasParameters, isAjaxTarget, isDisabled, isRenderLabelAndImage, removeState, render, renderImgTag, renderParameters, restoreState, saveState, setDisabled, setImageSrc, setLabel, setParameter, setParameters, setParameterValues, setRenderLabelAndImage, setState, setTabIndex, setTitle

Methods inherited from class org.apache.click.control.AbstractControl

addBehavior, addStyleClass, appendAttributes, dispatchActionEvent, getActionListener, getAttribute, getAttributes, getBehaviors, getContext, getControlSizeEst, getHeadElements, getHtmlImports, getMessage, getMessage, getMessages, getName, getPage, getParent, getStyle, getStyles, hasAttribute, hasAttributes, hasBehaviors, hasStyles, onDeploy, onDestroy, onInit, onRender, removeBehavior, removeStyleClass, renderTagBegin, renderTagEnd, setActionListener, setAttribute, setId, setListener, setStyle, toString

Methods inherited from class java.lang.Object

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

Field Detail

ACTION_LINK

public static final String ACTION_LINK

The action link parameter name: actionLink.

See Also:

Constant Field Values

VALUE

public static final String VALUE

The value parameter name: value.

See Also:

Constant Field Values

clicked

protected boolean clicked

The link is clicked.

Constructor Detail

ActionLink

public ActionLink(String name)

Create an ActionLink for the given name.

Please note the name 'actionLink' is reserved as a control request parameter name and cannot be used as the name of the control.

Parameters:

name - the action link name

Throws:

IllegalArgumentException - if the name is null

ActionLink

public ActionLink(String name,
                  String label)

Create an ActionLink for the given name and label.

Please note the name 'actionLink' is reserved as a control request parameter name and cannot be used as the name of the control.

Parameters:

name - the action link name

label - the action link label

Throws:

IllegalArgumentException - if the name is null

ActionLink

public ActionLink(Object listener,
                  String method)

Create an ActionLink for the given listener object and listener method.

Parameters:

listener - the listener target object

method - the listener method to call

Throws:

IllegalArgumentException - if the name, listener or method is null or if the method is blank

ActionLink

public ActionLink(String name,
                  Object listener,
                  String method)

Create an ActionLink for the given name, listener object and listener method.

Please note the name 'actionLink' is reserved as a control request parameter name and cannot be used as the name of the control.

Parameters:

name - the action link name

listener - the listener target object

method - the listener method to call

Throws:

IllegalArgumentException - if the name, listener or method is null or if the method is blank

ActionLink

public ActionLink(String name,
                  String label,
                  Object listener,
                  String method)

Create an ActionLink for the given name, label, listener object and listener method.

Please note the name 'actionLink' is reserved as a control request parameter name and cannot be used as the name of the control.

Parameters:

name - the action link name

label - the action link label

listener - the listener target object

method - the listener method to call

Throws:

IllegalArgumentException - if the name, listener or method is null or if the method is blank

ActionLink

public ActionLink()

Create an ActionLink with no name defined. Please note the control's name must be defined before it is valid.

Method Detail

isClicked

public boolean isClicked()

Returns true if the ActionLink was clicked, otherwise returns false.

Returns:

true if the ActionLink was clicked, otherwise returns false.

getHref

public String getHref(Object value)

Return the ActionLink anchor <a> tag href attribute for the given value. This method will encode the URL with the session ID if required using HttpServletResponse.encodeURL().

Parameters:

value - the ActionLink value parameter

Returns:

the ActionLink HTML href attribute

getHref

public String getHref()

Return the ActionLink anchor <a> tag href attribute value.

Specified by:

getHref in class AbstractLink

Returns:

the ActionLink anchor <a> tag HTML href attribute value

setName

public void setName(String name)

Set the name of the Control. Each control name must be unique in the containing Page model or the containing Form.

Please note the name 'actionLink' is reserved as a control request parameter name and cannot be used as the name of the control.

Specified by:

setName in interface Control

Overrides:

setName in class AbstractControl

Parameters:

name - of the control

Throws:

IllegalArgumentException - if the name is null

See Also:

Control.setName(String)

setParent

public void setParent(Object parent)

Set the parent of the ActionLink.

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)

getValue

public String getValue()

Returns the ActionLink value if the action link was processed and has a value, or null otherwise.

Returns:

the ActionLink value if the ActionLink was processed

getValueDouble

public Double getValueDouble()

Returns the action link Double value if the action link was processed and has a value, or null otherwise.

Returns:

the action link Double value if the action link was processed

Throws:

NumberFormatException - if the value cannot be parsed into a Double

getValueInteger

public Integer getValueInteger()

Returns the ActionLink Integer value if the ActionLink was processed and has a value, or null otherwise.

Returns:

the ActionLink Integer value if the action link was processed

Throws:

NumberFormatException - if the value cannot be parsed into an Integer

getValueLong

public Long getValueLong()

Returns the ActionLink Long value if the ActionLink was processed and has a value, or null otherwise.

Returns:

the ActionLink Long value if the action link was processed

Throws:

NumberFormatException - if the value cannot be parsed into a Long

setValue

public void setValue(String value)

Set the ActionLink value.

Parameters:

value - the ActionLink value

setValueObject

public void setValueObject(Object object)

Set the value of the ActionLink using the given object.

Parameters:

object - the object value to set

bindRequestValue

public void bindRequestValue()

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

Overrides:

bindRequestValue in class AbstractLink

onProcess

public boolean onProcess()

This method will set the isClicked() property to true if the ActionLink was clicked, and if an action callback listener was set this will be invoked.

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()