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h2.  Overview

*Result Types* are classes that determine what happens after an Action executes and a Result is returned. Developers are free to create their own Result Types according to the needs of their application or environment. In WebWork 2 for example, Servlet and Velocity Result Types have been created to handle rendering views in web applications.

+Note:+ All built in webwork result types implement the {{

Overview

Result Types are classes that determine what happens after an Action executes and a Result is returned. Developers are free to create their own Result Types according to the needs of their application or environment. In WebWork 2 for example, Servlet and Velocity Result Types have been created to handle rendering views in web applications.

...

com.opensymphony.xwork.Result}} interface, which represents a generic interface for all action execution results, whether that be displaying a webpage, generating an email, sending a JMS message, etc.

...



Result types define classes and map them to names to be referred in the action configuration results. This serves as a shorthand name-value pair for these classes.

...

Code Block

<!-- parts of xwork.xml  -->
....
 
{code|title=snippet of webwork-default.xml}
...
<result-types>
    <result-type name="dispatcher" class="com.opensymphony.webwork.dispatcher.ServletDispatcherResult" default="true"/>
    <result-type name="redirect" class="com.opensymphony.webwork.dispatcher.ServletRedirectResult"/>
    <result-type name="velocity" class="com.opensymphony.webwork.dispatcher.VelocityResult"/>
    <result-type name="chain" class="com.opensymphony.xwork.ActionChainResult"/>
    <result-type name="xslt" class="com.opensymphony.webwork.views.xslt.XSLTResult"/>
    <result-type name="jasper" class="com.opensymphony.webwork.views.jasperreports.JasperReportsResult"/>
    <result-type name="freemarker" class="com.opensymphony.webwork.views.freemarker.FreemarkerResult"/>
</result-types>

....
<!-- this action uses the result type dispatcher which is defined above -->

<action name="bar" class="myPackage.barAction">
  <result name="success" type="dispatcher">
    <param name="location">foo.jsp</param>
  </result>
  <result name="error" type="dispatcher">
    <param name="location">error.jsp</param>
  </result>
</action>

....

Result Types

...

    <result-type name="httpheader" class="com.opensymphony.webwork.dispatcher.HttpHeaderResult"/>
    <result-type name="stream" class="com.opensymphony.webwork.dispatcher.StreamResult"/>
</result-types>
...
{code}

{code|title=snippet of your xwork.xml}
<include file="webwork-default.xml"/>

<package name="myPackage" extends="default">
  <action name="bar" class="myPackage.barAction">
    <!-- default result type is "dispatcher" -->
    <!-- default result name is "success" -->
    <result>foo.jsp</result>
    <result name="error">error.jsp</result>
    </result>
  </action>
</package>
{code}

h2. Result Types

Webwork provides several implementations of the {{com.opensymphony.xwork.Result}} interface to make web-based interactions with your actions simple.  These result types include:

...



|| Result Type

...

name

...

class

...

#Dispatcher

...

dispatcher

 || name || class ||
| [#Dispatcher] | dispatcher | com.opensymphony.webwork.dispatcher.ServletDispatcherResult

...

#Redirect

...

redirect

 |
| [#Redirect] | redirect | com.opensymphony.webwork.dispatcher.ServletRedirectResult

...

#Action Chaining

...

chain

 |
| [#Action Chaining] | chain | com.opensymphony.xwork.ActionChainResult

...

#Velocity

...

velocity

 |
| [#Velocity] | velocity | com.opensymphony.webwork.dispatcher.VelocityResult

...

#FreeMarker

...

freemarker

 |
| [#FreeMarker] | freemarker | com.opensymphony.webwork.views.freemarker.FreemarkerResult

...

#JasperReports

...

jasper

 |
| [#JasperReports] | jasper | com.opensymphony.webwork.views.jasperreports.JasperReportsResult

...

 |
| [#XML/XSL

...

xslt

] | xslt | com.opensymphony.webwork.views.xslt.XSLTResult

...

#HttpHeader

...

 

 |
| [#HttpHeader] |  | com.opensymphony.webwork.dispatcher.HttpHeaderResult

...

 |

Results are specified in a xwork xml config file(xwork.xml) nested inside <action>.  If the {{location}} param is the only param being specified in the result tag, you can simplify it as follows:

...



{code
}
<action name="bar" class="myPackage.barAction">
  <result name="success" type="dispatcher">
    <param name="location">foo.jsp</param>
  </result>
</action>
{code}
or simplified

...


{code
}
<action name="bar" class="myPackage.barAction">
  <result name="success" type="dispatcher">foo.jsp</result>
</action>
{code}

+NOTE:+ The Parse attribute enables the location element to be parsed for expressions.  An example of how this could be useful:

...


{code
}
<result name="success" type="redirect">/displayCart.action?userId=${userId}</result>

{code}

+NOTE:+ You can also specify global-results to use with multiple actions.  This can save time from having to add the same result to many different actions. For more information on result tags and global-results, see [Results] section.

...

Includes or forwards to a view (usually a jsp). Behind the scenes WebWork will use a RequestDispatcher, where the target servlet/JSP receives the same request/response objects as the original servlet/JSP. Therefore, you can pass data between them using request.setAttribute() – the WebWork action is available.

Parameters

Required

Description

location

yes

the location to go to after execution (ex. jsp)

parse

no

true by default. If set to false, the location param will not be parsed for Ognl expressions

Code Block


h4. Dispatcher {anchor:Dispatcher}

Includes or forwards to a view (usually a jsp). Behind the scenes WebWork will use a RequestDispatcher, where the target servlet/JSP receives the same request/response objects as the original servlet/JSP. Therefore, you can pass data between them using request.setAttribute() -- the WebWork action is available.

||Parameters || Required || Description ||
| location | *yes* |  the location to go to after execution (ex. jsp) |
| parse | no | true by default. If set to false, the location param will not be parsed for Ognl expressions |

{code}
<result name="success" type="dispatcher">
    <param name="location">foo.jsp</param>
</result>

...


{code}

h4. Redirect {anchor:Redirect}

The response is told to redirect the browser to the specified location (a new request from the client).  The consequence of doing this means that the action (action instance, action errors, field errors, etc) that was just executed is lost and no longer available.  This is because actions are built on a single-thread model. The only way to pass data is through the session or with web parameters (url?name=value) which can be OGNL expressions.

...

Parameters

Required

Description

location

yes

the location to go to after execution

parse

no

true by default. If set to false, the location param will not be parsed for Ognl expressions

Code Block
 

||Parameters || Required || Description ||
| location | *yes* |  the location to go to after execution |
| parse | no | true by default. If set to false, the location param will not be parsed for Ognl expressions |

{code}
<result name="success" type="redirect">
    <param name="location">foo.jsp</param>
    <param name="parse">false</param>
</result>

...

A special kind of view that invokes GenericDispatch (using the previously existing ActionContext) and executes another action. This is useful if you need to execute one action immediately after another.

Parameters

Required

Description

actionName

yes

the name of the action that will be chained to

namespace

no

sets the namespace of the Action that we're chaining to. If namespace is null, this defaults to the current namespace.

Code Block
{code}

h4. Action Chaining {anchor:Action Chaining}

A special kind of view that invokes GenericDispatch (using the previously existing ActionContext) and executes another action.  This is useful if you need to execute one action immediately after another.

||Parameters || Required || Description ||
| actionName | *yes* | the name of the action that will be chained to
| namespace | no | sets the namespace of the Action that we're chaining to.  If namespace is null, this defaults to the current namespace. |

{code}
<result name="success" type="chain">
    <param name="actionName">bar</param>
    <param name="namespace">/foo</param>
</result>
{code}
invokes this

...


{code
}
<action name="bar" class="myPackage.barAction">
    ...
</action>

...

This result mocks a JSP execution environment and then displays a Velocity template that will be streamed directly to the servlet output.

Parameters

Required

Description

location

yes

the location to go to after execution

parse

no

true by default. If set to false, the location param will not be parsed for Ognl expressions

Code Block

{code}

h4. Velocity {anchor:Velocity}

This result mocks a JSP execution environment and then displays a Velocity template that will be streamed directly to the servlet output.

||Parameters || Required || Description ||
| location | *yes* |  the location to go to after execution |
| parse | no | true by default. If set to false, the location param will not be parsed for Ognl expressions |

{code}
<result name="success" type="velocity">
    <param name="location">foo.vm</param>
</result>

...

Parameters

...

Required

...

Description

...

location

...

yes

...

the location to go to after execution

...

parse

...

no

...

true by default. If set to false, the location param will not be parsed for Ognl expressions

...

contentType

...

no

...

{code}

h4. FreeMarker {anchor:FreeMarker}

||Parameters || Required || Description ||
| location | *yes*|  the location to go to after execution |
| parse | no | true by default. If set to false, the location param will not be parsed for Ognl expressions |
| contentType | no | defaults to "text/html" unless specified

...

Code Block
 |

{code}
<result name="success" type="freemarker">foo.ftl</result>

...

Generates a JasperReports report using the specified format or PDF if no format is specified.

Parameters

Required

Description

location

yes

the location to go to after execution

parse

no

true by default. If set to false, the location param will not be parsed for Ognl expressions

dataSource

yes

the Ognl expression used to retrieve the datasource from the value stack (usually a List)

format

no

the format in which the report should be generated, defaults to pdf

contentDisposition

no

defaults to "inline" when using documentName unless specified

documentName

no

generates the http header "Content-disposition = <contentDisposition>; filename=<documentName>.<format>"

Code Block

{code}

h4. JasperReports {anchor:JasperReports}

Generates a JasperReports report using the specified format or PDF if no format is specified.

||Parameters || Required || Description ||
| location | *yes* |  the location to go to after execution |
| parse | no | true by default. If set to false, the location param will not be parsed for Ognl expressions |
| dataSource | *yes* | the Ognl expression used to retrieve the datasource from the value stack (usually a List) |
| format | no |the format in which the report should be generated, defaults to pdf |
| contentDisposition | no | defaults to "inline" when using documentName unless specified |
| documentName | no | generates the http header "Content-disposition = <contentDisposition>; filename=<documentName>.<format>" |

{code}
<result name="success" type="jasper">
    <param name="location">foo.jasper</param>
    <param name="dataSource">mySource</param>
    <param name="format">CSV</param>
</result>
{code}
or for pdf

...


{code
}
<result name="success" type="jasper">
    <param name="location">foo.jasper</param>
    <param name="dataSource">mySource</param>
</result>

{code}

h4. XML/XSL

...

 {anchor

...

:XML/XSL

...

Interfaces with xml transformations.

Parameters

Required

Description

location

yes

the location to go to after execution

parse

no

Defaults to false. If set to true, the location will be parsed for Ognl expressions

Code Block
}

Interfaces with xml transformations.

||Parameters || Required || Description ||
| location | *yes* |  the location to go to after execution |
| parse | no | Defaults to false. If set to true, the location will be parsed for Ognl expressions |

{code}
<result name="success" type="xslt">foo.xslt</result>

...

A custom Result type for evaluating HTTP headers against the ValueStack.

Parameters

Required

Description

status

no

the http servlet response status code that should be set on a response

parse

no

true by default. If set to false, the headers param will not be parsed for Ognl expressions

headers

no

header values

Example:

Code Block
xmlxml
{code}


h4. HttpHeader {anchor:HttpHeader}

A custom Result type for evaluating HTTP headers against the ValueStack.

||Parameters || Required || Description ||
| status | no |  the http servlet response status code that should be set on a response |
| parse | no | true by default. If set to false, the *headers* param will not be parsed for Ognl expressions |
| headers| no | header values|

Example:
{code:xml}
<result name="success" type="header">
    <param name="status">204</param>
    <param name="headers.a">a custom header value</param>
    <param name="headers.b">another custom header value</param>
</result>
{code}