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Keith Donald
2008-04-09 13:38:22 +00:00
parent 2226b1d487
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27
spring-webflow-reference/src/spring-faces.xml
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@@ -5,31 +5,20 @@
<sect1 id="spring-faces-introduction">
<title>Introduction</title>
<para>
Spring Faces is Spring's JSF integration module that ships with the Spring Web Flow 2.0 distribution and
aims to simplify the programming model for using JSF with Spring. It provides support for using JSF in a
Spring-centric environment using Spring MVC and Spring Web Flow for control flow and event handling.
Spring Faces is Spring's JSF integration module that simplifies using JSF with Spring.
It lets you use the JSF UI Component Model with Spring MVC and Spring Web Flow controllers.
</para>
<para>
It includes a lightweight Facelets component library that focuses on providing rich client-side behavior and
Ajax support through the use of progressive enhancement. The client-side functionality of the component
library is provided by Spring JavaScript, an integration layer that aims to be agnostic to the underlying
client-side JavaScript toolkit. Spring Faces also aims to ensure that other JSF component libraries
integrate smoothly with Spring Web Flow, for the cases where a more desktop-like UI is desired as opposed to
the lightweight approach of the Spring Faces components.
Spring Faces also includes a small Facelets component library that provides Ajax and client-side validation capabilities.
This component library builds on Spring Javascript, a Javascript abstraction framework that integrates Dojo as the underlying UI toolkit.
</para>
</sect1>
<sect1 id="spring-faces-integration">
<title>Spring-centric Integration Approach</title>
<para>
Spring Faces aims to emphasize the strengths of JSF (i.e, its component model and EL binding) while
providing an alternative controller model that addresses many of its traditional weaknesses. Spring Faces
requests are routed through the Spring MVC DispatcherServlet instead of the FacesServlet, and the JSF
lifecycle is executed within the context of the current flow execution. Whereas pure JSF requests are
essentially driven by the current JSF view in a pull-oriented fashion, routing through the Spring
infrastructure allows for more flexible request processing with many well-defined extension points for
initialization and manipulation of the model and event-handling mechanisms that enable a reduced dependence
on the JSF API.
Spring Faces combines the strengths of JSF, its UI component model, with the strengths of Spring, its controller and configuration model.
This brings you all the strengths of JSF without any of the weaknesses.
</para>
<para>
Spring Faces provides a powerful supplement to a number of the standard JSF facilities, including:
@@ -45,13 +34,13 @@
<listitem>Ajax partial page updates and full navigation</listitem>
<listitem>progressive enhancement and graceful degradation</listitem>
</orderedlist>
Using these features will significantly reduce the amount of configuration required in faces-config.xml
while providing a cleaner separation between the view and controller layer and better modularization of your
application's functional responsibilities. These use of these features are outlined in the sections to
follow. As the majority of these features build on the flow definition language of Spring Web Flow, it is
assumed that you have an understanding of the foundations presented in
<link linkend="defining-flows">Defining Flows</link>
.
<link linkend="defining-flows">Defining Flows</link>.
</para>
</sect1>
<sect1 id="spring-faces-managed-beans">

4
spring-webflow-reference/src/spring-webflow-reference.xml
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@@ -5,8 +5,10 @@
<!ENTITY overview SYSTEM "overview.xml">
<!ENTITY defining-flows SYSTEM "defining-flows.xml">
<!ENTITY el SYSTEM "el.xml">
<!ENTITY views SYSTEM "views.xml">
<!ENTITY flow-security SYSTEM "flow-security.xml">
<!ENTITY flow-inheritance SYSTEM "flow-inheritance.xml">
<!ENTITY spring-faces SYSTEM "spring-faces.xml">
<!ENTITY upgrade-guide SYSTEM "upgrade-guide.xml">
<!ENTITY flow-definition-field-mappings SYSTEM "flow-definition-field-mappings.xml">
]>
@@ -70,8 +72,10 @@
&overview;
&defining-flows;
&el;
&views;
&flow-security;
&flow-inheritance;
&spring-faces;
&upgrade-guide;
&flow-definition-field-mappings;

287
spring-webflow-reference/src/views.xml Normal file
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@@ -0,0 +1,287 @@
<?xml version="1.0" encoding="UTF-8"?>
<chapter id="el">
<title>Rendering Views</title>
<sect1 id="views-introduction">
<title>Introduction</title>
<para>
This chapter shows you how to use the view-state element to render views within a flow.
</para>
</sect1>
<sect1 id="view-convention">
<title>view-state</title>
<para>
Use the <code>view-state</code> element to define a step of the flow that renders a view and waits for a user event to resume:
</para>
<programlisting language="xml">
&lt;view-state id="enterBookingDetails" &gt;
&lt;transition on="submit" to="reviewBooking" /&gt;
&lt;/view-state&gt;
</programlisting>
<para>
By convention, a view-state maps its id to a view template in the directory where the flow is located.
For example, the state above might render <filename>/WEB-INF/hotels/booking/enterBookingDetails.xhtml</filename>
if the flow itself was located in the <filename>/WEB-INF/hotels/booking</filename> directory.
</para>
<para>
Below is a sample directory structure showing views and other resources like message bundles co-located with their flow definition:
</para>
</sect1>
<sect1 id="view-explicit">
<title>Explicit view ids</title>
<para>
Use the <code>view</code> attribute to explictly specify the id of the view to render.
</para>
<sect2 id="view-explicit-flowrelative">
<title>Flow relative view ids</title>
<para>
The view id may be a relative path to view resource in the flow's working directory:
</para>
<programlisting language="xml">
&lt;view-state id="enterBookingDetails" view="bookingDetails.xhtml"&gt;
</programlisting>
</sect2>
<sect2 id="view-explicit-absolute">
<title>Absolute view ids</title>
<para>
The view id may be a absolute path to a view resource in the webapp root directory:
</para>
<programlisting language="xml">
&lt;view-state id="enterBookingDetails" view="/WEB-INF/hotels/booking/bookingDetails.xhtml"&gt;
</programlisting>
</sect2>
<sect2 id="view-explicit-absolute">
<title>Logical view ids</title>
<para>
With some view frameworks, such as Spring MVC's view framework, the view id may also be a logical identifier resolved by the framework:
</para>
<programlisting language="xml">
&lt;view-state id="enterBookingDetails" view="bookingDetails"&gt;
</programlisting>
<para>
See the Spring MVC integration section for more information on how to integrate with the MVC <code>ViewResolver</code> infrastructure.
</para>
</sect2>
<para>
A sample directory structure showing views and other resources co-located with their flow is shown below:
</para>
<mediaobject>
<imageobject role="fo">
<imagedata fileref="images/flow-view-packaging.png" format="PNG" align="center"/>
</imageobject>
<imageobject role="html">
<imagedata fileref="images/flow-view-packaging.png" format="PNG" align="center"/>
</imageobject>
<caption>
<para>Flow Packaging</para>
</caption>
</mediaobject>
</sect1>
<sect1 id="view-scope">
<title>viewScope</title>
<para>
A view-state allocates a new <code>viewScope</code> when it enters.
This scope may be referenced within the view-state to assign variables that should live for the duration of the state.
This scope is useful for manipulating objects over a series of requests from the same view, often Ajax requests.
A view-state destroys its viewScope when it exits.
</para>
<sect2 id="view-scope-actions">
<title>Assigning a viewScope variable using an Action</title>
<para>
Variables are often assigned before the view renders:
</para>
<programlisting language="xml">
&lt;on-render&gt;
&lt;evaluate expression="bookingService.findHotels(searchCriteria)" result="viewScope.hotels" result-type="dataModel" /&gt;
&lt;/on-render&gt;
</programlisting>
</sect2>
<sect2 id="view-scope-actions">
<title>Using the var tag to allocate view variables</title>
<para>
Use the <code>var</code> tag to declare a view variable.
Like a flow variable, any @Autowired references are automatically restored when the view state resumes.
</para>
<programlisting language="xml">
&lt;var name="searchCriteria" class="com.mycompany.myapp.hotels.SearchCriteria" /&gt;
</programlisting>
</sect2>
<sect2 id="view-scope-ajax">
<title>Manipulating objects view scope</title>
<para>
Objects in view scope are often manipulated over a series of requests from the same view.
The following example illustrates paginiation through a search results list.
The list is updated in view scope before each render.
Asynchronous event handlers modify the current data page, then request re-rendering of the search results fragment.
</para>
<programlisting language="xml">
&lt;view-state id="searchResults"&gt;
&lt;on-render&gt;
&lt;evaluate expression="bookingService.findHotels(searchCriteria)" result="viewScope.hotels" result-type="dataModel" /&gt;
&lt;/on-render&gt;
&lt;transition on="next"&gt;
&lt;evaluate expression="searchCriteria.nextPage()" /&gt;
&lt;render fragments="searchResultsTFragment" /&gt;
&lt;/transition&gt;
&lt;transition on="previous"&gt;
&lt;evaluate expression="searchCriteria.previousPage()" /&gt;
&lt;render fragments="searchResultsFragment" /&gt;
&lt;/transition&gt;
&lt;/view-state&gt;
</programlisting>
</sect2>
</sect1>
<sect1 id="view-on-render">
<title>on-render</title>
<para>
Use the <code>on-render</code> element to execute one or more actions before view rendering
Render actions are executed on the initial render as well as any subsequent refreshes, including any partial re-renderings of the view.
</para>
<programlisting language="xml">
&lt;on-render&gt;
&lt;evaluate expression="bookingService.findHotels(searchCriteria)" result="viewScope.hotels" result-type="dataModel" /&gt;
&lt;/on-render&gt;
</programlisting>
</sect1>
<sect1 id="view-model">
<title>Model binding</title>
<para>
Use the <code>model</code> attribute to declare the model object the view binds to.
The following example declares the <code>enterBookingDetails</code> state manipulates the <code>booking</code> model:
</para>
<programlisting language="xml">
&lt;view-state id="enterBookingDetails" model="booking"&gt;
</programlisting>
<para>
The model may be in any accessible scope, such as <code>flowScope</code> or <code>viewScope</code>.
Specifying a <code>model</code> triggers the following behavior when a view event occurs:
</para>
<orderedlist>
<listitem><para>View-to-model binding. On view postback, form values are bound to model object properties for you.</para></listitem>
<listitem><para>Model validation. After binding, if the model object requires validation, that validation logic will be invoked.</para></listitem>
</orderedlist>
<para>
For a flow event to be generated that can drive a view state transition, model binding must complete successfully.
If model binding fails, the view is re-rendered to allow the user to revise their edits.
</para>
<para>
The exact model binding and validation semantics are a function of the view technology in use.
See the Spring MVC and Faces section for more information on MVC and JSF semantics, respectively.
Regardless of the view technology used, the flow definition metadata should not change.
</para>
</sect1>
<sect1 id="view-bind">
<title>bind</title>
<para>
Use the <code>bind</code> attribute to suppress model binding and validation for particular view events.
</para>
<programlisting language="xml">
&lt;view-state id="enterBookingDetails"&gt;
&lt;transition on="proceed" to="reviewBooking"&gt;
&lt;transition on="cancel" to="bookingCancelled" bind="false" /&gt;
&lt;/view-state&gt;
</programlisting>
</sect1>
<sect1 id="view-validate">
<title>Validation</title>
<para>
Model validation is driven by constraints specified against the model object.
These constraints may be specified declaratively, or enforced using a programmatic validation routine or external <code>Validator</code>.
</para>
<sect2 id="view-validation-programmatic">
<title>Programmatic validation</title>
<para>
There are two ways to perform model validation programatically.
</para>
<sect3 id="view-validation=programmatic-validate-method">
<title>Implementing a model validate method</title>
<para>
The first way has you define a validate method on the model object class.
To do this, create a public method with the name <code>validate&lt;state&gt;</code>, where <code>state</code> is the id of the view-state.
The method must declare a <code>MessageContext</code> parameter for recording validation error messages.
For example:
</para>
<programlisting language="java">
public void validateEnterBookingDetails(MessageContext context) {
Calendar calendar = Calendar.getInstance();
calendar.add(Calendar.DAY_OF_MONTH, -1);
if (checkinDate.before(calendar.getTime())) {
context.addMessage(new MessageBuilder().error().source("checkinDate").defaultText(
"Check in date must be a future date").build());
} else if (!checkinDate.before(checkoutDate)) {
context.addMessage(new MessageBuilder().error().source("checkoutDate").defaultText(
"Check out date must be later than check in date").build());
}
}
</programlisting>
</sect3>
<sect3 id="view-validation=programmatic-validator">
<title>Implementing a Validator</title>
<para>
The second way has you define a separate object, called a Validator, which validates your model object.
To do this, create a class that defines a public method with the name <code>validate&lt;state&gt;</code>, where <code>state</code> is the id of the view-state.
The method must declare a <code>Object</code> parameter to accept your model object, and a <code>MessageContext</code> parameter for recording validation error messages.
For example:
</para>
<programlisting language="java">
public class BookingValidator {
public void validateEnterBookingDetails(Object object, MessageContext context) {
Booking booking = (Booking) object;
Calendar calendar = Calendar.getInstance();
calendar.add(Calendar.DAY_OF_MONTH, -1);
if (booking.getCheckinDate().before(calendar.getTime())) {
context.addMessage(new MessageBuilder().error().source("checkinDate").defaultText(
"Check in date must be a future date").build());
} else if (!booking.getCheckinDate().before(checkoutDate)) {
context.addMessage(new MessageBuilder().error().source("checkoutDate").defaultText(
"Check out date must be later than check in date").build());
}
}
}
</programlisting>
<para>
A Validator can also accept a Spring MVC <code>Errors</code> object, useful for invoking existing Spring Validators.
</para>
</sect3>
</sect2>
</sect1>
<sect1 id="simple-event-handlers">
<title>Event handlers</title>
<para>
From a view-state, transitions without targets can also be defined. Such transitions are called "event handlers":
</para>
<programlisting language="xml">
&lt;transition on="event"&gt;
&lt;-- Handle event --&gt;
&lt;/transition&gt;
</programlisting>
<para>
These event handlers do not change the state of the flow.
They simply execute their actions and re-render the current view or one or more fragments of the current view.
</para>
<sect2 id="event-handlers-render">
<title>render</title>
<para>
Use the <code>render</code> element to request partial re-rendering of a view after handling an event:
</para>
<programlisting language="xml">
&lt;transition on="next"&gt;
&lt;evaluate expression="searchCriteria.nextPage()" /&gt;
&lt;render fragments="searchResultsTFragment" /&gt;
&lt;/transition&gt;
</programlisting>
</sect2>
</sect1>
<sect1 id="view-popup">
<title>popup</title>
<para>
Use the <code>popup</code> attribute to indicate the view should be rendered in a model popup dialog:
</para>
<programlisting language="java">
&lt;view-state id="changeSearchCriteria" view="enterSearchCriteria.xhtml" popup="true"&gt;
</programlisting>
<para>
When using Web Flow with the Spring Javascript, no client side code is necessary for the popup to display.
Web Flow will send a response to the client requesting a redirect to the view from a popup, and the client will honor the request.
</para>
</sect1>
</chapter>