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Click is a web application framework. You may read the Java Web Programming Overview fist.

Click needs a servlet container such as Apache Tomcat.

To get the Click examples served from your own tomcat server, just copy click-2.1.0/dist/click-examples.war into $CATALINA_HOME/webapps and point your browser to http://localhost:8080/click-examples Note that Tomcat extracts the .war file into the webapps dir and serves content from the extracted directory and not from the war file. More

We call our first project translator and create a directory for it. This dir is our project root.

We roughly follow the Quick Start Guide and copy the most files from click-2.1.0/template/ into our project to ajust them for our needs.

Application configuration: Copy click-2.1.0/template/WebContent/WEB-INF/click.xml from the Click distribution to translator/WebContent/WEB-INF/click.xml. Specify among others your Java package name, eg. sb.translator.page and optionally the charset, the locale, the logging / caching mode and autobinding of controls in the application configuration file. More

Servlet configuration: Copy & paste the servlet configuration file translator/WebContent/WEB-INF/web.xml directly from the quick start guide. This file is for specifying the location of the ClickServlet and the servlet is mapped to process all *.htm URL requests. More

Copy click-2.1.0.jar and click-extras-2.1.0.jar into translator/WebContent/WEB-INF/WEB-INF/lib

Create your first java file in your java package path, eg translator/src/sb/translator/page/HomePage.java

Copy click-2.1.0/template/build.xml into our project root and run ant

Project structure:

translator/
|-- WebContent
|   |-- WEB-INF
|   |   |-- click.xml
|   |   |-- lib
|   |   |   |-- click-2.1.0.jar
|   |   |   `-- click-extras-2.1.0.jar
|   |   `-- web.xml
|   |-- home.htm
|   `-- redirect.html
|-- build.xml
`-- src
    `-- sb
        `-- translator
            `-- page
                `-- HomePage.java

Make a symlink from Tomcat to your project $CATALINA_HOME/webapps/translator → translator/WebContent in order to get your page in the browser.

1. The URL request to eg home.htm is automatically mapped to the class Home.java, or, if not found: HomePage.java. More
2. If no associated class can be found, redirect.html is used which results in the default URL (eg. home.htm) and finally in the associated default class (HomePage.java).
3. The associated Velocity template for the class is specified by the requested file in the URL, eg. home.htm
4. The associated Velocity template may by modified by the class by overwriting the getTemplate method of the Page class.

How to add the same default bordering HTML to each Page in order to get the same look for all pages?

1. Extend a Page class BorderedPage from Page
2. Overwrite getTemplate() so that always border-template.htm is returned as Velocity template.
3. Create your bordering HTML in border-template.htm
4. Add the Velocity directive #parse($path) to border-template.htm. This will be replaced with the real template file.
5. Extend all your Page classes from BorderedPage, not from Page

More

How to prevent caching without resart of Tomcat?

Why is @Bindable not recognized? Add more jar files?? Look in Template!

Verify this paragraph!

Java classes can be accessed by the Velocity templates by adding them to the model Map of the Page class. Adding can be done explicitely (by calling a method), implizitely (by making them public) or by using an annotation. More: Page class overview, Autobinding

Distinguish between plain dynamic data types like String or Date and Click Control types like Checkbox or FormTable.

Plain data types are made available for the Velocity template by calling Page.addModel() in the constructor of the Page class or in Page.onInit().

Click Control types must be added with Page.addControl() in Page.onInit()

As default, all public attributes of a Page class are added automatically to the Page's model.

Alle attributes of a Page, annotated with @Bindable are added automatically to the Page's model.

The @Bindable annotation is only respected, when autobinding ist set to annotation in click.xml:

<pages package="sb.translator.page" autobinding="annotation"/>

Alle Java files must import Bindable:

import org.apache.click.util.Bindable;

Using the @Bindable annotation seems to be the best way of binding

Parameter data, which is sent with HTTP Get (or Post?) can be made available in the page class just by creating a public attribute with the same name. More.

The data is also available in the velocity template, because it is automatically added to the page's model