Components

java.lang.Object
- org.omnifaces.util.Components

```
public final class Components
extends Object
```
Collection of utility methods for the JSF API with respect to working with UIComponent.

Author:

Bauke Scholtz, Arjan Tijms

Method Summary

Methods
Modifier and Type	Method and Description
`static MethodExpressionActionListener`	`createActionListenerMethodExpression(String expression)` Create an action listener method expression based on the given EL expression.
`static AjaxBehavior`	`createAjaxBehavior(String expression)` Create an ajax behavior which should invoke an ajax listener method expression based on the given EL expression.
`static MethodExpression`	`createMethodExpression(String expression, Class<?> returnType, Class<?>... parameterTypes)` Create a method expression based on the given EL expression, the given return type and the given parameter types, if any.
`static ValueExpression`	`createValueExpression(String expression, Class<?> type)` Create an editable value expression based on the given EL expression and the given type.
`static MethodExpression`	`createVoidMethodExpression(String expression, Class<?>... parameterTypes)` Create a void method expression based on the given EL expression and the given parameter types, if any.
`static <T extends UIComponent> T`	`findComponent(String clientId)` Returns the UI component matching the given client ID search expression.
`static <T extends UIComponent> T`	`findComponentInChildren(UIComponent component, String clientId)` Returns the UI component matching the given client ID search expression relative to the point in the component tree of the given component, searching only in its children.
`static <T extends UIComponent> T`	`findComponentInParents(UIComponent component, String clientId)` Returns the UI component matching the given client ID search expression relative to the point in the component tree of the given component, searching only in its parents.
`static <T extends UIComponent> T`	`findComponentRelatively(UIComponent component, String clientId)` Returns the UI component matching the given client ID search expression relative to the point in the component tree of the given component.
`static <T extends UIComponent> List<T>`	`findComponentsInChildren(UIComponent component, Class<T> type)` Returns a list of UI components matching the given type in children of the given component.
`static <T> T`	`getAttribute(UIComponent component, String name)` Returns the attribute of the given component on the given name.
`static <T extends UIComponent> T`	`getClosestParent(UIComponent component, Class<T> parentType)` Returns from the given component the closest parent of the given parent type, or `null` if none is found.
`static UICommand`	`getCurrentCommand()` Returns the currently invoked UI command component, or `null` if there is none, which may happen when the current request is not a postback request at all, or when the view has been changed by for example a successful navigation.
`static UIComponent`	`getCurrentComponent()` Returns the current UI component from the EL context.
`static UIForm`	`getCurrentForm()` Returns the currently submitted UI form component, or `null` if there is none, which may happen when the current request is not a postback request at all, or when the view has been changed by for example a successful navigation.
`static <T> T`	`getImmediateValue(UIInput input)` Returns the value of the given input component whereby any unconverted submitted string value will immediately be converted/validated as this method is called.
`static String`	`getLabel(UIComponent input)` Returns the value of the `label` attribute associated with the given UI component if any, else the client ID.
`static String`	`getOptionalLabel(UIComponent input)` Returns the value of the `label` attribute associated with the given UI component if any, else null.
`static <T> T`	`getValue(EditableValueHolder component)` Returns the value of the given editable value holder component without the need to know if the given component has already been converted/validated or not.
`static boolean`	`hasInvokedSubmit(UIComponent component)` Returns whether the given component has invoked the form submit.
`static boolean`	`hasSubmittedValue(EditableValueHolder component)` Returns whether the given editable value holder component has a submitted value.
`static UIComponent`	`includeCompositeComponent(UIComponent parent, String libraryName, String resourceName, String id)` Create and include the composite component of the given library and resource name as child of the given UI component parent and return the created composite component.
`static void`	`includeFacelet(UIComponent parent, String path)` Include the Facelet file at the given (relative) path as child of the given UI component parent.
`static boolean`	`isEditable(UIInput input)` Returns whether the given UI input component is editable.
`static boolean`	`isRendered(UIComponent component)` Returns whether the given UI component and all of its parents is rendered.
`static boolean`	`shouldVisitSkipIteration(VisitContext context)` Returns true if the given visit context contains the visit hint that iteration should be skipped.
`static <T extends UIComponent> void`	`validateHasDirectParent(UIComponent component, Class<T> parentType)` Validate if the given component has a direct parent of the given parent type.
`static void`	`validateHasNoChildren(UIComponent component)` Validate if the given component has no children.
`static <T extends UIComponent> void`	`validateHasParent(UIComponent component, Class<T> parentType)` Validate if the given component has a parent of the given parent type.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - getCurrentComponent
```
public static UIComponent getCurrentComponent()
```
    Returns the current UI component from the EL context.
    
    Returns:
    The current UI component from the EL context.
    See Also:
    UIComponent.getCurrentComponent(FacesContext)
  - getAttribute
```
public static <T> T getAttribute(UIComponent component,
                 String name)
```
    Returns the attribute of the given component on the given name.
    
    Type Parameters:
    T - The expected return type.
    Parameters:
    component - The component to return the attribute of the given name for.
    name - The name of the attribute of the given component to be returned.
    
    Returns:
    The attribute of the given component on the given name.
    
    Throws:
    
    ClassCastException - When T is of wrong type.
    Since:
    
    1.5
  - isRendered
```
public static boolean isRendered(UIComponent component)
```
    Returns whether the given UI component and all of its parents is rendered. This thus not only checks the component's own rendered attribute, but also of all of its parents.
    
    Parameters:
    component - The component to be checked.
    
    Returns:
    true if the given UI component and all of its parents is rendered.
    Since:
    
    1.8
  - findComponent
```
public static <T extends UIComponent> T findComponent(String clientId)
```
    Returns the UI component matching the given client ID search expression.
    
    Parameters:
    clientId - The client ID search expression.
    
    Returns:
    The UI component matching the given client ID search expression.
    
    Throws:
    
    ClassCastException - When T is of wrong type.
    See Also:
    UIComponent.findComponent(String)
  - findComponentRelatively
```
public static <T extends UIComponent> T findComponentRelatively(UIComponent component,
                                                String clientId)
```
    Returns the UI component matching the given client ID search expression relative to the point in the component tree of the given component. For this search both parents and children are consulted, increasingly moving further away from the given component. Parents are consulted first, then children.
    
    Parameters:
    component - the component from which the relative search is started.
    clientId - The client ID search expression.
    
    Returns:
    The UI component matching the given client ID search expression.
    
    Throws:
    
    ClassCastException - When T is of wrong type.
    See Also:
    UIComponent.findComponent(String)
  - findComponentInParents
```
public static <T extends UIComponent> T findComponentInParents(UIComponent component,
                                               String clientId)
```
    Returns the UI component matching the given client ID search expression relative to the point in the component tree of the given component, searching only in its parents.
    
    Parameters:
    component - the component from which the relative search is started.
    clientId - The client ID search expression.
    
    Returns:
    The UI component matching the given client ID search expression.
    
    Throws:
    
    ClassCastException - When T is of wrong type.
    See Also:
    UIComponent.findComponent(String)
  - findComponentInChildren
```
public static <T extends UIComponent> T findComponentInChildren(UIComponent component,
                                                String clientId)
```
    Returns the UI component matching the given client ID search expression relative to the point in the component tree of the given component, searching only in its children.
    
    Parameters:
    component - the component from which the relative search is started.
    clientId - The client ID search expression.
    
    Returns:
    The UI component matching the given client ID search expression.
    
    Throws:
    
    ClassCastException - When T is of wrong type.
    See Also:
    UIComponent.findComponent(String)
  - findComponentsInChildren
```
public static <T extends UIComponent> List<T> findComponentsInChildren(UIComponent component,
                                                       Class<T> type)
```
    Returns a list of UI components matching the given type in children of the given component.
    
    Parameters:
    component - The component to search in its children for UI components matching the given type.
    type - The type of the UI components to be searched in children of the given component.
    
    Returns:
    A list of UI components matching the given type in children of the given component.
    
    Throws:
    
    ClassCastException - When T is of wrong type.
  - getClosestParent
```
public static <T extends UIComponent> T getClosestParent(UIComponent component,
                                         Class<T> parentType)
```
    Returns from the given component the closest parent of the given parent type, or null if none is found.
    
    Type Parameters:
    T - The generic parent type.
    Parameters:
    component - The component to return the closest parent of the given parent type for.
    parentType - The parent type.
    
    Returns:
    From the given component the closest parent of the given parent type, or null if none is found.
    
    Throws:
    
    ClassCastException - When T is of wrong type.
  - shouldVisitSkipIteration
```
public static boolean shouldVisitSkipIteration(VisitContext context)
```
    Returns true if the given visit context contains the visit hint that iteration should be skipped.
    
    Parameters:
    context - The involved visit context.
    Since:
    
    1.3
  - includeFacelet
```
public static void includeFacelet(UIComponent parent,
                  String path)
                           throws IOException
```
    Include the Facelet file at the given (relative) path as child of the given UI component parent. This has the same effect as using <ui:include>. The path is relative to the current view ID and absolute to the webcontent root.
    
    Parameters:
    parent - The parent component to include the Facelet file in.
    path - The (relative) path to the Facelet file.
    
    Throws:
    
    IOException - Whenever something fails at I/O level. The caller should preferably not catch it, but just redeclare it in the action method. The servletcontainer will handle it.
    Since:
    
    1.5
    
    See Also:
    FaceletContext.includeFacelet(UIComponent, String)
  - includeCompositeComponent
```
public static UIComponent includeCompositeComponent(UIComponent parent,
                                    String libraryName,
                                    String resourceName,
                                    String id)
```
    Create and include the composite component of the given library and resource name as child of the given UI component parent and return the created composite component. This has the same effect as using <my:resourceName>. The given component ID must be unique relative to the current naming container parent and is mandatory for functioning of input components inside the composite, if any.
    
    Parameters:
    parent - The parent component to include the composite component in.
    libraryName - The library name of the composite component.
    resourceName - The resource name of the composite component.
    id - The component ID of the composite component.
    
    Returns:
    The created composite component, which can if necessary be further used to set custom attributes or value expressions on it.
    Since:
    
    1.5
  - getCurrentForm
```
public static UIForm getCurrentForm()
```
    Returns the currently submitted UI form component, or null if there is none, which may happen when the current request is not a postback request at all, or when the view has been changed by for example a successful navigation. If the latter is the case, you'd better invoke this method before navigation.
    
    Returns:
    The currently submitted UI form component.
    See Also:
    UIForm.isSubmitted()
  - getCurrentCommand
```
public static UICommand getCurrentCommand()
```
    Returns the currently invoked UI command component, or null if there is none, which may happen when the current request is not a postback request at all, or when the view has been changed by for example a successful navigation. If the latter is the case, you'd better invoke this method before navigation.
    
    Returns:
    The currently invoked UI command component.
    Since:
    
    1.6
  - isEditable
```
public static boolean isEditable(UIInput input)
```
    Returns whether the given UI input component is editable. That is when it is rendered, not disabled and not readonly.
    
    Parameters:
    input - The UI input component to be checked.
    
    Returns:
    true if the given UI input component is editable.
  - getLabel
```
public static String getLabel(UIComponent input)
```
    Returns the value of the label attribute associated with the given UI component if any, else the client ID. It never returns null.
    
    Parameters:
    input - The UI input component for which the label is to be retrieved.
    
    Returns:
    The value of the label attribute associated with the given UI component if any, else the client ID.
  - getOptionalLabel
```
public static String getOptionalLabel(UIComponent input)
```
    Returns the value of the label attribute associated with the given UI component if any, else null.
    
    Parameters:
    input - The UI input component for which the label is to be retrieved.
    
    Returns:
    The value of the label attribute associated with the given UI component if any, else null.
  - getValue
```
public static <T> T getValue(EditableValueHolder component)
```
    Returns the value of the given editable value holder component without the need to know if the given component has already been converted/validated or not. Note that it thus returns the unconverted submitted string value when the conversion/validation hasn't been taken place for the given component and it returns the converted object value -if applicable- when conversion/validation has been taken place for the given component.
    
    Parameters:
    component - The editable value holder component to obtain the value for.
    
    Returns:
    The value of the given editable value holder component.
    
    Throws:
    
    ClassCastException - When T is of wrong type.
  - getImmediateValue
```
public static <T> T getImmediateValue(UIInput input)
```
    Returns the value of the given input component whereby any unconverted submitted string value will immediately be converted/validated as this method is called. This method thus always returns the converted/validated value.
    
    Parameters:
    input - The input component to obtain the converted/validated value for.
    
    Returns:
    The converted/validated value of the given input component.
    
    Throws:
    
    ClassCastException - When T is of wrong type.
    Since:
    
    1.2
  - hasSubmittedValue
```
public static boolean hasSubmittedValue(EditableValueHolder component)
```
    Returns whether the given editable value holder component has a submitted value.
    
    Parameters:
    component - The editable value holder component to be checked.
    
    Returns:
    true if the given editable value holder component has a submitted value, otherwise false.
  - hasInvokedSubmit
```
public static boolean hasInvokedSubmit(UIComponent component)
```
    Returns whether the given component has invoked the form submit. In non-ajax requests, that can only be an UICommand component. In ajax requests, that can also be among others an UIInput component.
    
    Parameters:
    component - The component to be checked.
    
    Returns:
    true if the given component has invoked the form submit.
    Since:
    
    1.3
  - createValueExpression
```
public static ValueExpression createValueExpression(String expression,
                                    Class<?> type)
```
    Create an editable value expression based on the given EL expression and the given type.
    
    Parameters:
    expression - The EL expression to represent an editable value expression.
    type - The type of the property referenced by the value expression.
    
    Returns:
    The created editable value expression, ready to be used as UIComponent.setValueExpression(String, ValueExpression).
  - createMethodExpression
```
public static MethodExpression createMethodExpression(String expression,
                                      Class<?> returnType,
                                      Class<?>... parameterTypes)
```
    Create a method expression based on the given EL expression, the given return type and the given parameter types, if any. As an example, the following action method examples,
    - public void submit1()
    - public String submit2()
    - public void submit3(String argument)
    - public String submit4(String argument)
    - public void submit5(String argument1, Long argument2)
    - public String submit6(Long argument1, String argument2)
    can be created as follows:
    - createMethodExpression("#{bean.submit1}", Void.class);
    - createMethodExpression("#{bean.submit2}", String.class);
    - createMethodExpression("#{bean.submit3('foo')}", Void.class, String.class);
    - createMethodExpression("#{bean.submit4('foo')}", String.class, String.class);
    - createMethodExpression("#{bean.submit5('foo', 0)}", Void.class, String.class, Long.class);
    - createMethodExpression("#{bean.submit6(0, 'foo')}", String.class, Long.class, String.class);
    Parameters:
    expression - The EL expression to create a method expression for.
    returnType - The return type of the method expression. Can be null if you don't care about the return type (e.g. void or String).
    parameterTypes - The parameter types of the method expression.
    
    Returns:
    The created method expression, ready to be used as UICommand.setActionExpression(MethodExpression).
  - createVoidMethodExpression
```
public static MethodExpression createVoidMethodExpression(String expression,
                                          Class<?>... parameterTypes)
```
    Create a void method expression based on the given EL expression and the given parameter types, if any. As an example, the following action method examples,
    - public void submit1()
    - public void submit3(String argument)
    - public void submit5(String argument1, Long argument2)
    can be created as follows:
    - createVoidMethodExpression("#{bean.submit1}");
    - createVoidMethodExpression("#{bean.submit3('foo')}", String.class);
    - createVoidMethodExpression("#{bean.submit5('foo', 0)}", String.class, Long.class);
    Parameters:
    expression - The EL expression to create a void method expression for.
    parameterTypes - The parameter types of the void method expression.
    
    Returns:
    The created void method expression, ready to be used as UICommand.setActionExpression(MethodExpression).
  - createActionListenerMethodExpression
```
public static MethodExpressionActionListener createActionListenerMethodExpression(String expression)
```
    Create an action listener method expression based on the given EL expression. The target method must take an ActionEvent as argument. As an example, the following action method example,
    - public void actionListener(ActionEvent event)
    can be created as follows:
    - createActionListenerMethodExpression("#{bean.actionListener}");
    Parameters:
    expression - The EL expression to create an action listener method expression for.
    
    Returns:
    The created action listener method expression, ready to be used as UICommand.addActionListener(javax.faces.event.ActionListener).
  - createAjaxBehavior
```
public static AjaxBehavior createAjaxBehavior(String expression)
```
    Create an ajax behavior which should invoke an ajax listener method expression based on the given EL expression. The target method must take an AjaxBehaviorEvent as argument. As an example, the following ajax listener example,
    - public void ajaxListener(AjaxBehaviorEvent event)
    can be created as follows:
    - createAjaxBehavior("#{bean.ajaxListener}");
    Note that this is essentially the programmatic equivalent of <f:ajax>. So if you intented to create for example a <p:ajax> programmatically, then don't use this method.
    Parameters:
    expression - The EL expression to be invoked when the created ajax behavior is processed.
    
    Returns:
    The created ajax behavior, ready to be used as UIComponentBase.addClientBehavior(String, ClientBehavior) whereby the string argument represents the client event name, such as "action", "valueChange", "click", "blur", etc.
  - validateHasParent
```
public static <T extends UIComponent> void validateHasParent(UIComponent component,
                                             Class<T> parentType)
                              throws IllegalArgumentException
```
    Validate if the given component has a parent of the given parent type.
    
    Parameters:
    component - The component to be validated.
    parentType - The parent type to be checked.
    
    Throws:
    
    IllegalArgumentException - When the given component doesn't have any parent of the given type.
  - validateHasDirectParent
```
public static <T extends UIComponent> void validateHasDirectParent(UIComponent component,
                                                   Class<T> parentType)
                                    throws IllegalArgumentException
```
    Validate if the given component has a direct parent of the given parent type.
    
    Parameters:
    component - The component to be validated.
    parentType - The parent type to be checked.
    
    Throws:
    
    IllegalArgumentException - When the given component doesn't have a direct parent of the given type.
  - validateHasNoChildren
```
public static void validateHasNoChildren(UIComponent component)
                                  throws IllegalArgumentException
```
    Validate if the given component has no children.
    
    Parameters:
    component - The component to be validated.
    
    Throws:
    
    IllegalArgumentException - When the given component has any children.

Class Components

Method Summary

Methods inherited from class java.lang.Object

Method Detail

getCurrentComponent

getAttribute

isRendered

findComponent

findComponentRelatively

findComponentInParents

findComponentInChildren

findComponentsInChildren

getClosestParent

shouldVisitSkipIteration

includeFacelet

includeCompositeComponent

getCurrentForm

getCurrentCommand

isEditable

getLabel

getOptionalLabel

getValue

getImmediateValue

hasSubmittedValue

hasInvokedSubmit

createValueExpression

createMethodExpression

createVoidMethodExpression

createActionListenerMethodExpression

createAjaxBehavior

validateHasParent

validateHasDirectParent

validateHasNoChildren