Tapestry Components for Web 2.0

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Tapestry Components for Web 2.0

Howard Lewis Ship

TWD Consulting, Inc.

[email protected]

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What is Tapestry?

Application

PagePage

ComponentComponent ComponentComponent

ComponentComponent

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Controller

ModelView

HTML template Java Beans

Dynamic HTML output

Links / Form Submissions

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Login Form

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Border.html<div jwcid="loginDialog"> <div class="dialog"> <form jwcid="form"> <p> Enter your email address and password to log in. </p> <span jwcid="errors@Errors"/> <label jwcid="@FieldLabel" field="component:email"/> <input jwcid="email" size="30"/> <label jwcid="@FieldLabel" field="component:password"/> <input jwcid="password" size="30"/> <input type="submit" value="Login"/> <input jwcid="@Cancel" ajax="true"/> </form> <p> Not registered yet? <a jwcid="register2"> Click here to setup an account</a>. </p> </div></div>

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Border.html

Placeholder for tacos:Dialog component Dialogs are invisible until un-hidden Active dialogs mask the rest of the page

<div jwcid="loginDialog">

. . .

</div>

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Border.jwc

Dialog visibility from dialogHidden property of page

Login link: Set dialogHidden to false Re-render just the loginDialog

<component id="loginDialog" type="tacos:Dialog"> <binding name="hidden" value="dialogHidden"/></component>

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Border.jwc

Invoke the listener method Re-render just the loginDialog component

<component id="login" type="tacos:AjaxDirectLink"> <binding name="listener" value="listener:doShowLogin"/> <binding name="updateComponents" value="{ 'loginDialog' }"/></component>

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Form component

Tapestry forms are inside a Form component: Unique names & ids for fields (even inside loops) Tracking of user input and errors Handling submit, refresh & cancel AjaxForm: Partial page refreshes

<form jwcid="form"> . . .</form>

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Form Component

listener: Name of listener method to invoke delegate Object that tracks user input and

errors

<component id="form" type="tacos:AjaxForm"> <binding name="updateComponents" value="{ 'errors' }"/> <binding name="success" value="listener:doLogin"/> <binding name="cancel" value="listener:doCancel"/> <binding name="delegate" value="delegate"/></component>

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OGNL

Object Graph Navigation Language Expression language used by Tapestry ognl: prefix when used in HTML template No prefix when used in XML file

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OGNL

Simple: property namesdelegate getDelegate(),

setDelegate() Complex: property paths

poll.title getPoll().getTitle(), getPoll().setTitle()

Much more!

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TextField Component

@FieldLabel anonymous component of type FieldLabel Nothing in the Login.page file

component:email reference to email component

<label jwcid="@FieldLabel" field="component:email"/>:<input jwcid="email" size="30"/>

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TextField Component

value property to read and update validators validations to perform displayName Used in error messages, and

by FieldLabel

<component id="email" type="TextField"> <binding name="value" value="email"/> <binding name="validators" value="validators:required"/> <binding name="displayName" value="message:email-label"/></component>

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Password TextField

<component id="password" type="TextField"> <binding name="value" value="password"/> <binding name="validators" value="validators:required"/> <binding name="displayName" value="message:password-label"/> <binding name="hidden" value="true"/></component>

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Register Link

literal: value is just a string, not an OGNL expression

<p>Not registered yet? <a jwcid="register">Click here to setup an account</a>. </p>

<component id="register" type="PageLink"> <binding name="page" value="literal:Register"/> </component>

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Java Classpublic abstract class Border extends BaseComponent{

public abstract String getEmail();

public abstract String getPassword();

. . .

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Abstract?

Pages are stateful Hold transient data during request Hold persistent data between requests

Pages are expensive to create Pages are pooled

Like database connections

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No, Really, Abstract?

Tapestry extends abstract class Adds getter, setter, instance variables Adds end-of-request cleanup Lots of injections based on getters and

annotations (or XML)

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Embedded Components

Injected CodeApplication

Code

Inherited Code

Page Behavior

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Java Class

getEmail() & setEmail() getPassword() & setPassword()

public abstract class Border extends BaseComponent{

public abstract String getEmail();

public abstract String getPassword();

. . .

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Listener Methods

Public method Changes server side state Form will re-render

public void doCancel(){ getLoginDialog().hide();}

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Injecting Services

Service defined in HiveMind IoC Container Can inject Spring beans as easily Keep business logic out of pages / components

@InjectObject("service:epluribus.LoginAuthenticator")public abstract LoginAuthenticator getAuthenticator();

public interface LoginAuthenticator{ User authenticateCredentials(String email, String plaintextPassword);}

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Listener Methodspublic String doLogin() { String email = getEmail(); String password = getPassword();

User user = getAuthenticator().authenticateCredentials( email, password);

. . .

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Listener Methods . . .

if (user == null) { getDelegate().record(null, "Invalid user name or password."); return null; }

getIdentity().login(user);

getLoginDialog().hide();}

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Server Side State: ASO

Application State Objects Global to all pages Stored in HttpSession Created on demand Defined in HiveMind Injected into pages or components

@InjectState("identity")public abstract Identity getIdentity();

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Identity ASO

public class Identity implements Serializable { . . .

public boolean isLoggedIn() { . . . }

public void login(User user) { . . . } public void logout() { . . . }

public User getUser() { . . . }}

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Loops, Tables and Actions

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Home.html

<table class="data-grid" cellspacing="0" jwcid="polls"/>

<div jwcid="pollingEndColumnValue@Block"><span jwcid="@InsertDate" date="ognl:poll.pollingEnd"/></div>

<div jwcid="statusColumnValue@Block"><span jwcid="@Insert" value="ognl:responseCount"/><a jwcid="respond">Respond</a></div>

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Home.page

<property name="rowIndex"/>

<component id="polls" type="contrib:Table"> <binding name="source" value="polls"/> <binding name="columns" value="message:table-columns"/> <binding name="row" value="poll"/> <binding name="index" value="rowIndex"/> <binding name="rowsClass"> rowIndex == 0 ? "first" : null </binding> </component>

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Home.page

Defines a new property on page Alternately: create abstract property



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Home.page

contrib: is name of tapestry-contrib.jar library



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Home.page

source total list of Poll objects



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Home.page



columns how to break a Poll object into columns

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Home.properties

column-id : title : OGNL expression poll.title poll.questionCount null calculated elsewhere

!status status is not sortable

table-columns=\ title:Title:title, \ questions:Questions:questionCount, \ pollingEnd:End of Polling:pollingEnd, \ !status:Status:null

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Home.page



row Property to update with each rendered row (each Poll)

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Home.page



index Stores index into row (used to set row CSS class)

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Home.page



rowsClass CSS class value for the <tr> Identify first row to change its formatting

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Home.html




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Home.html




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Home.page

DirectLink invokes a listener method when clicked

Can pass parameters into the listener method

<component id="respond" type="DirectLink"> <binding name="listener" value="listener:doRespond"/> <binding name="parameters" value="poll.id"/></component>

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Home.java

Parameters show up … with proper type (not just String)

@InjectPage("RespondToPoll")public abstract RespondToPoll getRespondToPoll();

public void doRespond(long pollId) { Poll poll = getPollAccess().getPoll(pollId);

// TODO: A few checks, i.e., Poll is active getRespondToPoll().activate(poll);}

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Creating New Components

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FCKEditor

"the text editor for the Internet" Open Source http://www.fckeditor.net/

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FCKEditor

Primarily a JavaScript library: FCKeditor/fckeditor.js

Goal: Component to take place of TextArea

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FCKEditor Component

FCKEditor.jwc Copy of TextArea.jwc FCKEditor extends TextArea

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FCKEditor.javaprotected void renderFormComponent(IMarkupWriter writer, IRequestCycle cycle){ super.renderFormComponent(writer, cycle);

// Now, we want to work with the script.

PageRenderSupport support = TapestryUtils.getPageRenderSupport(cycle, this);

support.addExternalScript(getEditorScript().getResourceLocation());

String contextPath = getRequest().getContextPath();

String id = getClientId();

String clientObject = "editor_" + id;

StringBuffer buffer = new StringBuffer();

buffer.append(String.format("var %s = new FCKeditor('%s');\n", clientObject, id)); buffer.append(String.format("%s.BasePath = '%s/FCKeditor/';\n", clientObject, contextPath)); buffer.append(String.format("%s.ReplaceTextarea();\n", clientObject));

support.addInitializationScript(buffer.toString());}

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FCKEditor.java

super.renderFormComponent(writer, cycle);

PageRenderSupport support = TapestryUtils.getPageRenderSupport(cycle, this);

support.addExternalScript( getEditorScript().getResourceLocation());

@Asset("context:FCKeditor/fckeditor.js")public abstract IAsset getEditorScript();

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FCKEditor.java

String contextPath = getRequest().getContextPath();

String id = getClientId();

String clientObject = "editor_" + id;

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FCKEditor.java

StringBuffer buffer = new StringBuffer();

buffer.append(String.format("var %s = new FCKeditor('%s');\n", clientObject, id));

buffer.append(String.format("%s.BasePath = '%s/FCKeditor/';\n", clientObject, contextPath));

buffer.append(String.format("%s.ReplaceTextarea();\n",

clientObject));

support.addInitializationScript(buffer.toString());

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FCKEditor Summary

Easy to knit components & JavaScript Super easy to use:

<input jwcid="@FCKEditor" value="ognl:description"/>

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Wrap Up

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More Tapestry Topics

Persistent Page Properties Creating New Components Localization Packaging component libraries Integration with Hibernate and Spring Unit and Integration Testing Extending and Overriding Tapestry

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ePluribus Source

Via Anonymous SVN:

http://svn.javaforge.com/svn/tapestry/epluribus/trunk

User: anonymous Password: anon

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Links

Tapestry http://tapestry.apache.org

HiveMind http://jakarta.apache.org/hivemind/ http://hivemind.apache.org/

Tacos http://tacos.sf.net/

OGNL http://www.ognl.org/

Tapestry Components for Web 2.0

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