| <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> |
| |
| <!-- |
| Copyright 1999-2004 The Apache Software Foundation |
| Licensed under the Apache License, Version 2.0 (the "License"); |
| you may not use this file except in compliance with the License. |
| You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, software |
| distributed under the License is distributed on an "AS IS" BASIS, |
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| See the License for the specific language governing permissions and |
| limitations under the License. |
| --> |
| |
| |
| <!-- Content Stylesheet for Site --> |
| |
| |
| <!-- start the processing --> |
| <!-- ====================================================================== --> |
| <!-- GENERATED FILE, DO NOT EDIT, EDIT THE XML FILE IN xdocs INSTEAD! --> |
| <!-- Main Page Section --> |
| <!-- ====================================================================== --> |
| <html> |
| <head> |
| <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"/> |
| |
| <meta name="author" value="Velocity Documentation Team"> |
| <meta name="email" value="jvanzyl@zenplex.com"> |
| |
| |
| |
| |
| <title>Velocity - Velocity Design</title> |
| </head> |
| |
| <body bgcolor="#ffffff" text="#000000" link="#525D76"> |
| <table border="0" width="100%" cellspacing="0"> |
| <!-- TOP IMAGE --> |
| <tr> |
| <td align="left"> |
| <a href="http://jakarta.apache.org"><img src="http://jakarta.apache.org/images/jakarta-logo.gif" border="0"/></a> |
| </td> |
| <td align="right"> |
| <a href="http://jakarta.apache.org/velocity/"><img src="./images/logo.gif" alt="Velocity" border="0"/></a> |
| </td> |
| </tr> |
| </table> |
| <table border="0" width="100%" cellspacing="4"> |
| <tr><td colspan="2"> |
| <hr noshade="" size="1"/> |
| </td></tr> |
| |
| <tr> |
| <!-- LEFT SIDE NAVIGATION --> |
| <td width="20%" valign="top" nowrap="true"> |
| |
| <!-- ============================================================ --> |
| |
| <p><strong>About</strong></p> |
| <ul> |
| <li> <a href="./index.html">Overview</a> |
| </li> |
| <li> <a href="./getting-started.html">Getting Started</a> |
| </li> |
| <li> <a href="http://jakarta.apache.org/builds/jakarta-velocity/">Download</a> |
| </li> |
| <li> <a href="./install.html">Install</a> |
| </li> |
| <li> <a href="./design.html">Design</a> |
| </li> |
| <li> <a href="./contributors.html">Contributors</a> |
| </li> |
| <li> <a href="./changes.html">ChangeLog</a> |
| </li> |
| <li> <a href="./code-standards.html">Coding Standards</a> |
| </li> |
| <li> <a href="./license.html">License</a> |
| </li> |
| <li> <a href="./todo.html">TODO</a> |
| </li> |
| <li> <a href="http://issues.apache.org/bugzilla/enter_bug.cgi?product=Velocity">Report Issues</a> |
| </li> |
| </ul> |
| <p><strong>Community</strong></p> |
| <ul> |
| <li> <a href="./powered.html">Powered By Velocity</a> |
| </li> |
| <li> <a href="http://jakarta.apache.org/site/getinvolved.html">Get Involved</a> |
| </li> |
| <li> <a href="http://jakarta.apache.org/site/mail.html">Mailing Lists</a> |
| </li> |
| <li> <a href="http://jakarta.apache.org/site/cvsindex.html">CVS Repositories</a> |
| </li> |
| </ul> |
| <p><strong>Docs</strong></p> |
| <ul> |
| <li> <a href="./user-guide.html">User's Guide (English)</a> |
| </li> |
| <li> <a href="./user-guide_fi.html">User's Guide (Finnish)</a> |
| </li> |
| <li> <a href="./user-guide_fr.html">User's Guide (French)</a> |
| </li> |
| <li> <a href="./user-guide_es.html">User's Guide (Spanish)</a> |
| </li> |
| <li> <a href="./developer-guide.html">Developer's Guide</a> |
| </li> |
| <li> <a href="./vtl-reference-guide.html">VTL Reference Guide</a> |
| </li> |
| <li> <a href="./specification.html">Specification</a> |
| </li> |
| <li> <a href="./api/index.html">Javadoc</a> |
| </li> |
| </ul> |
| <p><strong>Tools</strong></p> |
| <ul> |
| <li> <a href="./tools/index.html">Velocity Tools</a> |
| </li> |
| <li> <a href="./anakia.html">Anakia : XML->doc tool</a> |
| </li> |
| <li> <a href="./texen.html">Texen : text generation</a> |
| </li> |
| <li> <a href="./dvsl/index.html">DVSL : XML xformation</a> |
| </li> |
| <li> <a href="./veltag.html">Veltag : JSP taglib</a> |
| </li> |
| <li> <a href="./migration.html">Migration to Velocity</a> |
| </li> |
| <li> <a href="./devtools.html">Editors and IDEs</a> |
| </li> |
| </ul> |
| <p><strong>Comparisons</strong></p> |
| <ul> |
| <li> <a href="./ymtd/ymtd.html">YMTD</a> |
| </li> |
| <li> <a href="./differences.html">VM/WM Differences</a> |
| </li> |
| <li> <a href="./casestudy1.html">JSP vs. Velocity</a> |
| </li> |
| <li> <a href="./casestudy2.html">XMLC vs. Velocity</a> |
| </li> |
| </ul> |
| <p><strong>Site Translations</strong></p> |
| <ul> |
| <li> <a href="http://jakarta.apache.org/velocity/">English</a> |
| </li> |
| <li> <a href="http://www.ingrid.org/jajakarta/velocity/velocity-1.2-rc2/docs-ja/index.html">Japanese</a> |
| </li> |
| </ul> |
| </td> |
| <td width="80%" align="left" valign="top"> |
| <table border="0" cellspacing="0" cellpadding="2" width="100%"> |
| <tr><td bgcolor="#525D76"> |
| <font color="#ffffff" face="arial,helvetica,sanserif"> |
| <a name="Design"><strong>Design</strong></a> |
| </font> |
| </td></tr> |
| <tr><td> |
| <blockquote> |
| <p> |
| Velocity is a Java-based template engine. It can be used as a |
| standalone utility for generating source code, HTML, reports, |
| or it can be combined with other systems to provide template |
| services. Velocity will be tightly integrated with the |
| <a href="http://java.apache.org/turbine">Turbine</a> |
| web application framework. Velocity-Turbine |
| provide a template service by which web applications may be |
| developed according to a true MVC model. |
| </p> |
| <p> |
| Velocity has a myriad of potential uses -- generating SQL, PostScript, |
| or Java source code from templates -- but web developers looking for |
| a viable alternative to |
| <a href="http://www.php.net/">PHP</a> and |
| <a href="http://java.sun.com/products/jsp/">Java |
| Server Pages</a> (JSPs) are expected to be its principle user group. |
| </p> |
| <p> |
| Velocity allows web page designers to embed simple yet powerful script |
| elements in their web pages. These script elements work |
| in conjunction with a Context object, which is defined in Java code. |
| A context object--essentially a hashtable that provides get and set |
| methods for retrieving and setting objects by name within the Context |
| --provides a "hook" from the Java code to the Velocity script |
| elements. These script elements allow a web designer to retrieve |
| objects from the Context and insert these into a web page as text |
| values. The web designer has some control over looping (for each) |
| and conditional statements (if/else). |
| </p> |
| <p> |
| Velocity enforces a Model-View-Controller (MVC) style of development |
| by separating Java code from HTML template code. Unlike JSPs, |
| Velocity does not allow Java code to be embedded in pages. Unlike PHP, |
| Velocity does not implement features with other functions. The MVC |
| approach is one of Velocity's great strengths, and allows for more |
| maintainable and better-designed web pages. |
| </p> |
| <p> |
| Although MVC-style development can sometimes lead to longer incubation |
| periods for web sites, particularly if the developers involved are new |
| to MVC, this approach saves time over the long term (believe us, we have |
| been doing this for a long time now). The MVC abstraction prevents web page |
| designers from messing with a software engineer's Java code, and |
| programmers from unduly influencing the look of web sites. Velocity enforces |
| a contract that defines what roles people play in the web site development |
| process. |
| </p> |
| <p> |
| Velocity uses a grammar-based parser generated by |
| <a href="http://www.metamata.com/javacc/">JavaCC</a> (Java Compiler |
| Compiler) using the JJTree extension to create an Abstract Syntax Tree. |
| </p> |
| <p> |
| Velocity's design concept is borrowed from <a href="http://www.webmacro.org/">WebMacro</a>. Those involved in the |
| Velocity project acknowledge and appreciate the development and design work |
| that went into the WebMacro project. |
| </p> |
| </blockquote> |
| </p> |
| </td></tr> |
| <tr><td><br/></td></tr> |
| </table> |
| </td> |
| </tr> |
| |
| <!-- FOOTER --> |
| <tr><td colspan="2"> |
| <hr noshade="" size="1"/> |
| </td></tr> |
| <tr><td colspan="2"> |
| <div align="center"><font color="#525D76" size="-1"><em> |
| Copyright © 1999-2004, The Apache Software Foundation |
| </em></font></div> |
| </td></tr> |
| </table> |
| </body> |
| </html> |
| <!-- end the processing --> |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
