| <HTML><HEAD><TITLE>Velocity Todo</TITLE></HEAD><BODY alink="#023264" bgcolor="#ffffff" leftmargin="4" link="#023264" marginheight="4" marginwidth="4" text="#000000" topmargin="4" vlink="#023264"><TABLE border="0" cellpadding="0" cellspacing="0" width="100%"><TR><TD align="left" valign="top"><A href="http://jakarta.apache.org/index.html"><IMG border="0" hspace="0" src="resources/jakarta-logo.gif" vspace="0"></A></TD><TD align="left" bgcolor="#ffffff" valign="top" width="100%"><IMG align="right" alt="" border="0" hspace="0" src="resources/header.gif" vspace="0"></TD></TR><TR><TD><IMG border="0" height="5" hspace="0" src="resources/void.gif" vspace="0" width="5"></TD></TR><TR><TD background="resources/line.gif" colspan="2" height="2" width="100%"><IMG alt="" border="0" height="2" hspace="0" src="resources/line.gif" vspace="0" width="1"></TD></TR></TABLE><TABLE border="0" cellpadding="0" cellspacing="0" width="100%"><TR><TD valign="top" width="1%"></TD><TD nowrap="1" valign="top" width="14%"><BR> |
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| <P></P> |
| <FONT face="arial,helvetica,sanserif" size="-1"><LI><A href="index.html">Overview</A></LI></FONT> |
| <FONT face="arial,helvetica,sanserif" size="-1"><LI><A href="getting-started.html">Getting Started</A></LI></FONT> |
| <FONT face="arial,helvetica,sanserif" size="-1"><LI><A href="install.html">Install</A></LI></FONT> |
| <FONT face="arial,helvetica,sanserif" size="-1"><LI><A href="design.html">Design</A></LI></FONT> |
| <FONT face="arial,helvetica,sanserif" size="-1"><LI><A href="contributors.html">Contributors</A></LI></FONT> |
| <FONT face="arial,helvetica,sanserif" size="-1"><LI><A href="code-standards.html">Coding Standards</A></LI></FONT> |
| <FONT face="arial,helvetica,sanserif" size="-1"><LI><A href="license.html">License</A></LI></FONT> |
| <FONT face="arial,helvetica,sanserif" size="-1"><LI><A href="todo.html">TODO</A></LI></FONT> |
| <P></P> |
| <FONT face="arial,helvetica,sanserif" size="-1"><LI><A href="user-guide.html">User's Guide</A></LI></FONT> |
| <FONT face="arial,helvetica,sanserif" size="-1"><LI><A href="developer-guide.html">Developer's Guide</A></LI></FONT> |
| <FONT face="arial,helvetica,sanserif" size="-1"><LI><A href="vtl-reference-guide.html">VTL Reference Guide</A></LI></FONT> |
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| <DIV align="right"><TABLE border="0" cellpadding="0" cellspacing="0" width="98%"><TR><TD bgcolor="#023264" width="100%"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="5" hspace="0" src="resources/void.gif" vspace="0" width="5"><B>Todo</B></FONT></TD></TR><TR><TD><IMG border="0" height="5" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE><TABLE border="0" cellpadding="0" cellspacing="0" width="98%"><TR><TD><FONT color="#000000" face="arial,helvetica,sanserif"> |
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| <P align="justify"> |
| This is an informal document describing what needs to |
| be done in the Velocity code base and the |
| Velocity documentation. If you need more detailed help, or have specific |
| questions, please send mail to the mailing list |
| (<A href="mailto:velocity-dev@jakarta.apache.org">velocity-dev@jakarta.apache.org</A>). |
| The Todo list that follows is roughly in order of importance. |
| </P> |
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| </FONT></TD></TR></TABLE></DIV><BR> |
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| <DIV align="right"><TABLE border="0" cellpadding="0" cellspacing="0" width="98%"><TR><TD bgcolor="#023264" width="100%"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="5" hspace="0" src="resources/void.gif" vspace="0" width="5"><B>The List</B></FONT></TD></TR><TR><TD><IMG border="0" height="5" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE><TABLE border="0" cellpadding="0" cellspacing="0" width="98%"><TR><TD><FONT color="#000000" face="arial,helvetica,sanserif"> |
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| <B>Runtime API</B> |
| <BR> |
| The Velocity Runtime is the single access point for all |
| Velocity's functionality. A standard API for the |
| Runtime should be defined so that in the span between |
| the 0.5 Milestone release and a 1.0 release, the Runtime |
| API changes as little as possible. |
| <P align="justify"></P> |
| |
| <B>JUnit Test Suite</B> |
| <BR> |
| A JUnit test suite would allow Velocity developers to |
| aggressively add, refactor, and optimize code. We need |
| a comprehensive test suite so that we can |
| be assured changes in the code base have no adverse |
| effects for users. <A href="mailto:dlr@collab.net">Daniel L. Rall</A> |
| has started us off with some code so you may want to contact |
| him if you are interested in working on a JUnit test suite. |
| <P align="justify"></P> |
| |
| <B>Directive Interface</B> |
| <BR> |
| Right now there is a very thin interface for directives, but |
| some knowledge of JavaCC is required. The directive |
| interface is not intended to be used outside core Velocity |
| developers (it is not intended to be a public API), but it |
| probably makes sense to shield directive creators from JavaCC. |
| <P align="justify"></P> |
| |
| <B>Context</B> |
| <BR> |
| The Velocity Context class is still fairly primitive. It |
| loosely adheres to a Map, but it definitely needs some |
| thinking. It works fine now, but it might be good to |
| think about: how to load standard tools and how to |
| make that process efficient; how to stamp items in |
| the context with expiry durations so that items can |
| be cached and how this might work. |
| <P align="justify"></P> |
| |
| <B>Sample Applications</B> |
| <BR> |
| Any type of sample application would be useful to |
| help new developers get acquainted with |
| Velocity. Any suggestions are welcome. |
| <P align="justify"></P> |
| |
| <B>User's Guide</B> |
| <BR> |
| This would be a guide for designers who would |
| be using the Velocity Template Language (VTL) to |
| create templates. The users guide would give |
| example usage and a definitive description |
| of the VTL syntax. <A href="mailto:jvanzyl@periapt.com">Jason van Zyl</A> |
| has started work on this with John Castura, but any and all |
| suggestions are welcome. |
| <P align="justify"></P> |
| |
| <B>Developer Guide</B> |
| <BR> |
| This would be a guide for developers who would use |
| Velocity as a standalone servlet tool, or in conjuction |
| with a servlet controller framework like Turbine. |
| <A href="mailto:jvanzyl@periapt.com">Jason van Zyl</A> is |
| currently working on this guide, but any and all suggestions |
| are welcome. |
| <P align="justify"></P> |
| |
| <B>Template Loader System</B> |
| <BR> |
| The template loader system is functional but could probably use an |
| overhaul. There is currently a double template instantiation |
| problem. It is not causing any serious problems, but it |
| should be corrected. We could utilize some |
| object caching/pooling code from Turbine, or JServ, or the |
| Avalon Server Framework. |
| <P align="justify"></P> |
| |
| <B>Caching</B> |
| <BR> |
| It would be good to have a discussion about how objects |
| in the context should be cached, how the caching |
| should be specified, and who should control the |
| caching: the designer, by specifying something in the template; |
| the developer, |
| by placing expiry times on objects placed in the context; |
| or a third party, such as a content manager. For example, |
| say an array consisting of a top 10 list of books is |
| placed in the context. This top 10 list might be valid |
| for a 24 hour period: how should that be specified? Say |
| a content manager later decides this list will be valid |
| for a week. Do they tell the designer, who in turn changes |
| the template, or could we provide a mechanism that would |
| allow a content manager to change the default expiry time |
| for that particular context object with the aid of a webapp |
| of some sort? The groundwork has be laid for a flexible |
| caching system in Velocity, but this discussion would be |
| one of usage and policy. |
| <P align="justify"></P> |
| |
| <B>Parser Pool</B> |
| <BR> |
| It would be good to create a pool of parsers that could |
| be utilized by the Runtime. Right now there is only a single |
| parser and the parsing is synchronized. The parsing doesn't |
| happen all that often in production, but a small pool of |
| parsers might alleviate any potential bottlenecks. Again, |
| object caching/pooling code could be borrowed from Turbine, |
| JServ, or the Avalon Server Framework. |
| <P align="justify"></P> |
| |
| <B>UML Overview</B> |
| <BR> |
| It would great to include a set of comprehensive |
| UML diagrams that describe Velocity. This would |
| allow new developers to get up to speed quickly. |
| <P align="justify"></P> |
| |
| <B>Velocity Profiling</B> |
| <BR> |
| If someone is handy with one of the standard profilers, |
| it would be great to start hunting for bottlenecks. No |
| serious optimization has been started. But in conjuction |
| with the presence of a JUnit test suite, optimization |
| changes could be made with confidence. It would be nice |
| to have a configuration of a setup for a common profiler |
| so that anyone who wanted to do some profiling could do |
| so in a consistent manner. |
| <P align="justify"></P> |
| |
| <B>Encoding Caching</B> |
| <BR> |
| What would this entail? And how could we implement an |
| efficient encoding caching mechanism. |
| <P align="justify"></P> |
| |
| <B>Plugins</B> |
| <BR> |
| It would be good to allow plugins in the form of JAR files |
| to be picked up the Velocity Runtime during startup. This |
| would be a good way for Velocity developers to share tools |
| that could be used in a context. For example there are some |
| utilities in Turbine that allow email to be sent from within |
| a template. It might be good to package this sort of utility |
| in a JAR file so that there are no dependencies in the |
| Velocity build for a specific utility. |
| <P align="justify"></P> |
| |
| <B>Context Tools</B> |
| <BR> |
| What kind of tools might be good to add to Velocity? There |
| are several utilties that have been created in Turbine that |
| might be good to move over to the Velocity code base. |
| <P align="justify"></P> |
| |
| <B>Syntax Dumper</B> |
| <BR> |
| Right now there is a primitive syntax dumper in the Velocity |
| code base, and it could be improved. This tool is very helpful |
| in debugging, and it is also good for creating directives. |
| It basically has a simple dump method that is used for all |
| the AST node types. It would be good to tailor dump methods |
| for particular AST node types so that the structure produced |
| is a little clearer. |
| <P align="justify"></P> |
| |
| <B>Syntax Checker</B> |
| <BR> |
| It would be good to have a standard syntax checker, something |
| that would find all syntax errors and report them to the |
| designer in some intelligible format. This tool could be |
| hooked into various designer tools like DreamWeaver. |
| <P align="justify"></P> |
| |
| <B>Extended Properties</B> |
| <BR> |
| There are classes that are present in JServ, Turbine and Cocoon |
| that allow a more flexible properties mechanism. It allows properties |
| files to be 'included', and allows the concatentation of the values |
| of multiply defined properties. These classes are very good and |
| should be integrated into Velocity. |
| <P align="justify"></P> |
| |
| <B>Compiler</B> |
| <BR> |
| It would be great to have a template compiler. There is a great |
| utility called JavaClass that provides a very clean and simple way |
| to create class files, and there is also some byte code generating |
| code present in the DynamicJava package that could be utilized. |
| <P align="justify"></P> |
| |
| <B>IDE Integration</B> |
| <BR> |
| How could Velocity be integrated into standard IDEs like |
| JBuilder and VisualAge? |
| <P align="justify"></P> |
| |
| <B>Scripting Language Integration</B> |
| <BR> |
| This is something that has been discussed on the Turbine |
| list. Allowing Context building classes to be written |
| in JPython, Rhino or other scripting languages would |
| dramatically improve development time and might allow technically |
| proficient web designers who are familiar JavaScript to create |
| an entire servlet solution with Velocity. As most of these |
| scripting solutions provide a compiler, performance would still |
| remain at an acceptable level. |
| <P align="justify"></P> |
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