be.atbash.util

Class ComponentUtils

java.lang.Object

be.atbash.util.ComponentUtils

public final class ComponentUtils
extends Object

Some utility methods related too JSF components.

Method Summary

Modifier and Type	Method and Description
static List<javax.faces.component.UIComponent>	findTargets(javax.faces.component.UIComponent component, String target) Searches for JSF Components within the UIComponent or his parents in the component tree.
static <T> T	getAttributeValue(javax.faces.component.UIComponent component, String attributeName, Class<T> resultClass) Returns the attribute value of a custom component.
static int	getMaxLength(javax.faces.component.UIComponent component, javax.faces.context.FacesContext facesContext) Return the maxLngth from the component (HtmlInputText.
static String	getStyle(javax.faces.component.UIComponent component, javax.faces.context.FacesContext facesContext) Return the style from the component (HtmlInputText or HtmlOutputLabel).
static String	getStyleClass(javax.faces.component.UIComponent component, javax.faces.context.FacesContext facesContext) Return the styleClass from the component (HtmlInputText, HtmlOutputLabel or HtmlSelectOneMenu).
static Object	getValue(javax.faces.component.UIComponent component, javax.faces.context.FacesContext facesContext) Return the value from the component (ValueHolder).
static boolean	isRequired(javax.faces.component.UIComponent component, javax.faces.context.FacesContext facesContext) Return the required info from the component (EditableValueHolder).
static void	processTargets(javax.faces.component.UIComponent component, String target, ComponentCallback callback) Searches for JSF Components within the UIComponent or his parents in the component tree.

Methods inherited from class java.lang.Object

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

Method Detail

getValue

public static Object getValue(javax.faces.component.UIComponent component,
                              javax.faces.context.FacesContext facesContext)

Return the value from the component (ValueHolder). It checks first the valueExpression, if not present then the getter is executed for retrieving fixed values.

Parameters:

component - JSF component to get the value from.

facesContext - The FacesContext

Returns:

The 'value' attribute of the JSF Component

isRequired

public static boolean isRequired(javax.faces.component.UIComponent component,
                                 javax.faces.context.FacesContext facesContext)

Return the required info from the component (EditableValueHolder). It checks first the valueExpression, if not present then the getter is executed for retrieving fixed values.

Parameters:

component - JSF component to get the value from.

facesContext - The FacesContext

Returns:

The 'required' attribute of the JSF Component

getStyle

public static String getStyle(javax.faces.component.UIComponent component,
                              javax.faces.context.FacesContext facesContext)

Return the style from the component (HtmlInputText or HtmlOutputLabel). It checks first the valueExpression, if not present then the getter is executed for retrieving fixed values.

Parameters:

component - JSF component to get the value from.

facesContext - The FacesContext

Returns:

The 'style' attribute of the JSF Component

getStyleClass

public static String getStyleClass(javax.faces.component.UIComponent component,
                                   javax.faces.context.FacesContext facesContext)

Return the styleClass from the component (HtmlInputText, HtmlOutputLabel or HtmlSelectOneMenu). It checks first the valueExpression, if not present then the getter is executed for retrieving fixed values.

Parameters:

component - JSF component to get the value from.

facesContext - The FacesContext

Returns:

The 'styleClass' attribute of the JSF Component

getMaxLength

public static int getMaxLength(javax.faces.component.UIComponent component,
                               javax.faces.context.FacesContext facesContext)

Return the maxLngth from the component (HtmlInputText. It checks first the valueExpression, if not present then the getter is executed for retrieving fixed values.

Parameters:

component - JSF component to get the value from.

facesContext - The FacesContext

Returns:

The 'maxLength' attribute of the JSF Component

getAttributeValue

public static <T> T getAttributeValue(javax.faces.component.UIComponent component,
                                      String attributeName,
                                      Class<T> resultClass)

Returns the attribute value of a custom component. The attribute name is defined as parameter of the method, just as the type. The method looks for a 'static' hardcoded value and an EL Value expression. In the latter case, the expression is evaluated.

Type Parameters:

T - The generic type.

Parameters:

component - The custom UIComponent.

attributeName - attribute name

resultClass - The class type of the attribute used for casting

Returns:

The value of the attribute of

findTargets

public static List<javax.faces.component.UIComponent> findTargets(javax.faces.component.UIComponent component,
                                                                  String target)

Searches for JSF Components within the UIComponent or his parents in the component tree. It is thus an extended version of the algorithm than the standard JSF algorithm UIComponent.findComponent() but comes with a potential performance. The algorithm is as follows.

• When target is empty, it returns the UIComponent itself
• the target is split around , and the search is performed for each id
• The id is search with the parent with a call to UIComponent.findComponent. Thus absolute ids are supported
• When no match is found, the search is repeated on the parent component (and this partially overlaps the previous search)

Parameters:

component - The Component where the search starts.

target - The id or set of ids (separated by ,) to be searched. Absolute ids (like :frm:field) are supported.

Returns:

List of Component matching the search ids.

processTargets

public static void processTargets(javax.faces.component.UIComponent component,
                                  String target,
                                  ComponentCallback callback)

Searches for JSF Components within the UIComponent or his parents in the component tree. It is thus an extended version of the algorithm than the standard JSF algorithm UIComponent.findComponent() but comes with a potential performance. For each component found, the callback is called.

• When target is empty, call callback method
• the target is split around , and the search is performed for each id
• The id is search with the parent with a call to UIComponent.findComponent. Thus absolute ids are supported
• When no match is found, the search is repeated on the parent component (and this partially overlaps the previous search)

For each target found, the callback is called. the detection is based on the fact the the parent of the component needs the attribute javax.faces.application.Resource.ComponentResource

Parameters:

component - The Component where the search starts.

target - The id or set of ids (separated by ,) to be searched. Absolute ids (like :frm:field) are supported.

callback - Process the found components.