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| <document> |
| <properties> |
| <title>DirectLink</title> |
| </properties> |
| <body> |
| |
| <section name="DirectLink"> |
| |
| <p> |
| Creates an <code><a></code> hyperlink that notifies the component when the link is |
| triggered. The link includes some context-specific data that is made available to |
| the component's listener. |
| </p> |
| <p> |
| See the Developers Guide DirectLink listeners for a more complete |
| description. |
| </p> |
| |
| <p> |
| <strong> |
| See also: |
| <a href="externallink.html">ExternalLink</a> |
| , |
| <a href="genericlink.html">GenericLink</a> |
| , |
| <a href="pagelink.html">PageLink</a> |
| , |
| <a href="servicelink.html">ServiceLink</a> |
| </strong> |
| |
| </p> |
| |
| <section name="Parameters"> |
| <table> |
| |
| <tr> |
| <th>Name</th> |
| <th>Type</th> |
| |
| <th>Required</th> |
| <th>Default</th> |
| |
| <th>Description</th> |
| </tr> |
| <tr> |
| <td>listener</td> |
| <td> |
| <a href="../../apidocs/org/apache/tapestry/IActionListener.html"> |
| IActionListener |
| </a> |
| </td> |
| <td>no</td> |
| <td> </td> |
| <td> |
| Specifies an object that is notified when the link is clicked, which is |
| typically a listener method of its container (for example, listeners. |
| <em>method</em>). If this parameter is not provided, Tapestry will attempt |
| to find a listener with the capitalized id of the component, prefixed by |
| "do". For example, jwcid="clear@DirectLink" would expect a listener called doClear(). |
| </td> |
| </tr> |
| <tr> |
| <td>parameters</td> |
| <td> |
| Object or |
| <br /> |
| |
| Object[] or |
| <br /> |
| List |
| </td> |
| <td>no</td> |
| <td> </td> |
| <td> |
| <p> |
| An array of objects to be encoded into the URL. These parameters |
| will be decoded when the link is triggered. |
| </p> |
| |
| <p> |
| In a web application built onto of Enterprise JavaBeans, the context |
| is often the primary key of some Entity bean; typically such keys |
| are Strings or Integers. |
| </p> |
| <p> |
| A listener method can retrieve the parameters three ways: |
| <br /> |
| parameters are declared in the method itself, e.g. - listenerMethod( |
| <em>parameters</em> |
| ) |
| <br /> |
| parameters are declared along with the IRequestCycle, e.g. - |
| listenerMethod(IRequestCycle cycle, |
| <em>parameters</em> |
| ) |
| |
| <br /> |
| or through the request cycle, e.g. - listenerMethod(IReuqestCycle |
| cycle), using IRequestCycle.getServiceParameters() |
| </p> |
| <p> |
| Prior to release 2.2, the parameters were always type String. They |
| may now be of any type; type will be maintained when the parameters |
| are later retrieved by a listener. See |
| <a |
| href="../../apidocs/org/apache/tapestry/util/io/SqueezeAdaptor.html"> |
| SqueezeAdaptor |
| </a> |
| for more details. |
| </p> |
| </td> |
| </tr> |
| |
| <tr> |
| <td>disabled</td> |
| <td>boolean</td> |
| <td>no</td> |
| <td>false</td> |
| |
| <td> |
| Controls whether the link is produced. If disabled, the portion of the |
| template the link surrounds is still rendered, but not the link itself. |
| </td> |
| </tr> |
| <tr> |
| <td>stateful</td> |
| <td>boolean</td> |
| <td>no</td> |
| <td>true</td> |
| <td> |
| If true (the default), then the component requires an active (i.e., |
| non-new) HttpSession when triggered. Failing that, it throws a |
| <a |
| href="../../apidocs/org/apache/tapestry/StaleLinkException.html"> |
| StaleLinkException |
| </a> |
| . If false, then no check is necessary. The latter works well with links |
| that encode all necessary state inside the URL itself. |
| </td> |
| </tr> |
| <tr> |
| <td>target</td> |
| |
| <td>String</td> |
| <td>no</td> |
| <td /> |
| <td> |
| The name of the html target for this link, this is just the normal html attribute that will |
| control where the response generated from this link will go. (Usually used in frames) |
| </td> |
| </tr> |
| <tr> |
| <td>anchor</td> |
| |
| <td>String</td> |
| <td>no</td> |
| <td /> |
| <td> |
| |
| The name of an anchor or element to link to. The final URL will have '#' |
| and the anchor appended to it. |
| </td> |
| |
| </tr> |
| |
| <tr> |
| <td>scheme</td> |
| <td>String</td> |
| <td>no</td> |
| <td> </td> |
| <td> |
| The required scheme ("http" or "https", typically) for the URL. This |
| will force the creation of an absolute URL when the current request's |
| scheme does not match the value for this parameter. This is most often |
| used to switch to "https" for secure portions of an application (such as |
| a login page), before switching back to standard "http" for the majority |
| of an application. |
| </td> |
| </tr> |
| |
| <tr> |
| <td>port</td> |
| <td>Integer</td> |
| <td>no</td> |
| <td> </td> |
| <td> |
| The required port (80, 443, 8080. 8443, typically) for the URL. This |
| will force the creation of an absolute URL when the current request's |
| scheme does not match the value for this parameter. This is most often |
| used in conjunction with scheme to switch to "https:443"/"https:8443" |
| for secure portions of an application (such as a login page), before |
| switching back to standard "http:80"/"http:80" for the majority of an |
| application. |
| </td> |
| </tr> |
| |
| <tr> |
| <td>renderer</td> |
| <td> |
| <a |
| href="../../apidocs/org/apache/tapestry/link/ILinkRenderer.html"> |
| ILinkRenderer |
| </a> |
| </td> |
| <td>no</td> |
| |
| <td> </td> |
| |
| <td>The object which will actually render the link.</td> |
| </tr> |
| <tr> |
| <td>updateComponents</td> |
| <td>String[],Collection</td> |
| <td>no</td> |
| <td> </td> |
| <td> |
| In an asynchronous request, specifies which components should have their content |
| rendered back to the client. These are expected to be unique component ids. |
| |
| <p> |
| See: <a href="../../apidocs/org/apache/tapestry/services/ResponseBuilder.html">ResponseBuilder</a> |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td>json</td> |
| <td>boolean</td> |
| <td>no</td> |
| <td>false</td> |
| <td> |
| Causes the request to be asynchronous and the response to be captured/rendered via |
| the <a href="../../apidocs/org/apache/tapestry/services/impl/JSONResponseBuilder.html">JSONResponseBuilder</a> |
| renderer. |
| </td> |
| </tr> |
| <tr> |
| <td>async</td> |
| <td>boolean</td> |
| <td>no</td> |
| <td>false</td> |
| <td> |
| Causes the request to be asynchronous and the response to be captured/rendered via |
| the <a href="../../apidocs/org/apache/tapestry/services/impl/DojoAjaxResponseBuilder.html">DojoAjaxResponseBuilder</a> |
| renderer. |
| </td> |
| </tr> |
| </table> |
| |
| <p> |
| Body: |
| <strong>rendered</strong> |
| |
| </p> |
| |
| <p> |
| |
| Informal parameters: |
| <strong>allowed</strong> |
| </p> |
| |
| <p> |
| Reserved parameters: |
| <em>href</em> |
| </p> |
| |
| </section> |
| <section name="Examples"> |
| |
| <p> |
| In this example the DirectLink component enables users to select a Customer from |
| the Customer List table. |
| </p> |
| |
| <img src="../../images/ComponentReference/DirectLink.png" |
| alt="DirectLink Screen Shot" /> |
| |
| |
| <p>HTML template</p> |
| <source xml:space="preserve"><![CDATA[ |
| <table cellspacing="6"> |
| <tr> |
| <td>ID</td> |
| <td> </td> |
| <td>Name</td> |
| <td> </td> |
| <td>Level</td> |
| <th> </th> |
| </tr> |
| <tr> |
| <td colspan="6"><hr></td> |
| </tr> |
| <tr jwcid="@Foreach" source="ognl:customerList" value="ognl:customer" element="tr"> |
| <td><span jwcid="@Insert" value="ognl:customer.id"/></td> |
| <td> </td> |
| <td><a jwcid="@DirectLink" listener="listener:customerSelectAction" parameters="ognl:customer.id"> <span jwcid="@Insert" value="ognl:customer.fullName"/> </a></td> |
| <td> </td> |
| <td><span jwcid="@Insert" value="ognl:customer.memberLevel"/></td> |
| <td> |
| <a jwcid="@DirectLink" listener="listener.customerDeleteAction" parameters="ognl:customer.id" onclick="return window.confirm('Are you sure you want remove this customer?');"> |
| <img jwcid="@Image" image="ognl:assets.deleteImage" alt="Delete"/> |
| </a> |
| </td> |
| </tr> |
| </table> |
| ]]></source> |
| |
| <p>Page specification</p> |
| <source xml:space="preserve"><![CDATA[ |
| <property name="customerList" type="java.util.List" persistent="yes"/> |
| <property name="customer" type="Customer"/> |
| ]]></source> |
| |
| |
| <p>Java sources</p> |
| <source xml:space="preserve"> |
| public abstract class SalesPage extends BasePage { |
| public abstract List getCustomerList(); |
| public abstract List setCustomerList(List value); |
| |
| public abstract Customer getCustomer(); |
| |
| public void customerSelectAction(Integer id) { |
| Visit visit = (Visit) getVisit(); |
| Customer customer = visit.findCustomerByPrimaryKey(id); |
| // Perform some action with the selected customer. |
| .. |
| } |
| |
| public void customerDeleteAction(Integer id) { |
| Visit visit = (Visit) getVisit(); |
| Customer customer = visit.findCustomerByPrimaryKey(id); |
| visit.deleteCustomer(customer); |
| } |
| } |
| </source> |
| <source xml:space="preserve"> |
| public class Visit() implements Serializable { |
| |
| public List getCustomerList() { |
| List customerList = new ArrayList(); |
| // Perform a database query retrieving the list of customers. |
| .. |
| return customerList; |
| } |
| |
| public Customer findCustomerByPrimaryKey(Integer id) { |
| Customer customer = null; |
| // Retrieve the customer from the database with given the customer ID. |
| .. |
| return customer; |
| } |
| |
| public void deleteCustomer(Customer customer) { |
| // Delete customer from the database. |
| .. |
| } |
| } |
| </source> |
| |
| <source xml:space="preserve"> |
| public class Customer implements Serializable { |
| private Integer id; |
| private String fullName; |
| private String memberLevel; |
| |
| public Customer(Integer id, String fullName, String memberLevel) { |
| this.id = id; |
| this.fullName = fullName; |
| this.memberLevel = memberLevel; |
| } |
| |
| public Integer getId() { return id; } |
| |
| public String getFullName() { return fullName; } |
| |
| public String getMemberLevel() { return memberLevel; } |
| } |
| </source> |
| </section> |
| |
| </section> |
| |
| </body> |
| </document> |
