New version of the cewolf chart tag library

[Ulf Dittmer]

cewolf is a tag library for embedding charts in JSP pages. While the project has been around for a while on SourceForge, updates haven't happened there for a few years. That is about to change in the not-too-distant future! I have maintained an enhanced distribution of the library for some time on my web site, and since I have been made a committer on the project on SourceForge, my version will become the official version at some point in the next few months. Until then, I invite everybody to check out the enhancements that have been made to cewolf since the last "official" release. Broadly speaking, those fall into these three areas:

Various bugs have been fixed, and some small enhancements made (like additional parameters to some of the tags)

Many more ChartPostProcessors ship with the library than used to be the case. These are Java classes that can be used to finetune the appearance and/or functionality of a chart. (cewolf uses the JFreeChart library, but doesn't expose all its functionality through the tags; post processors are a way of getting around that.)

Serialization was broken, resulting in exceptions at runtime. This has been fixed, although at the price of slight incompatibility with the previous version. Most people should not run into this, though.

All the details can be found on the web page, and questions can be asked in this thread here, or in the Other Open Source Projects forum.

[Pat Garner]

Perhaps you could forward the following message to Guido, since his email listed at Sourceforge is being returned (reason: 550 unknown user) and I am therefore unable to send him a message:

1. The Cewolf taglib documentation at cewolf.sourceforge.net indicates that the attribute tooltipgeneratorid of <map> should refer to a com.jrefinery.chart.tooltips.ToolTipGenerator object, but in the example in the tutorial the tool tip generator implements de.laures.cewolf.tooltips.CategoryToolTipGenerator, which creates confusion. It appears to me that jrefinery.com seems to have a squatter sitting on it.

2. The Cewolf taglib documentation does not indicate that the attribute 'id' is allowed for a <map> node. The only two attributes listed are linkgeneratorid and tooltipgeneratorid. However, in the example in the tutorial the id attribute is used, i.e. <cewolf:map id="pageViews"/>, and this is also confusing.

I am having difficulty getting tool tips to work in Firefox (the tool tips work in IE just fine, but not in Firefox) and such is the reason that I began looking at the Cewolf tool tip generator documentation more closely.

Meanwhile, if you, Ulf, would be able to provide clarification of the above two issues and indicate how I might get tool tips to work in Firefox I would greatly appreciate it! Thanks!

[Ulf Dittmer]

Guido has not been involved with cewolf for quite a while, so he would not be a good choice for addressing any questions.

I'll look into the documentation issues, but in the mean time, make sure you're using the latest distribution from my web site, not the one from SourceForge. One of the recent builds specifically addresses a problem with tooltips. If you're still experiencing a problem with that, then a SSCCE would help track down the problem.

[Ulf Dittmer]

1. The Cewolf taglib documentation at cewolf.sourceforge.net indicates that the attribute tooltipgeneratorid of <map> should refer to a com.jrefinery.chart.tooltips.ToolTipGenerator object, but in the example in the tutorial the tool tip generator implements de.laures.cewolf.tooltips.CategoryToolTipGenerator, which creates confusion.

I checked that the documentation is the distribution linked above does not have references to obsolete classes, so this should no longer be an issue.

2. The Cewolf taglib documentation does not indicate that the attribute 'id' is allowed for a <map> node. The only two attributes listed are linkgeneratorid and tooltipgeneratorid. However, in the example in the tutorial the id attribute is used, i.e. <cewolf:map id="pageViews"/>, and this is also confusing.

An "id" attribute is no longer supported by the map tag, and the examples in the current distribution don't use it.

So, this is more of a reminder to myself that I need to make my distribution the official one, lest folks use an obsolete version :-)

[Chris Sprehe]

Have you confirmed if the most recent cewolf distribution works with the latest JFreechart distribution (1.0.13)? I recently tried updating the JFreeChart version only to find that the tooltip no longer works and noticed that the underlying map generated by cewolf is slightly different than before updating the JFreeChart .jar.

[Ulf Dittmer]

Welcome to JavaRanch.

I have not confirmed it one way or another, but I've had reports before that there's a tooltip bug when using cewolf with the latest JFree version. That's the reason cewolf comes bundled with an older JFree version. That's no loss in functionality since cewolf does not make use of the latest JFree features.

[Chris Sprehe]

Thank you for the quick response. Ulf, per your posts above, are you still updating the cewolf distribution actively ... i.e. eventually to take advantage of any of the latest features?

[Ulf Dittmer]

I'm actively fixing bugs (in cewolf, not in JFree), occasionally adding features, and patching in contributions by users. I've not kept up to date on what's happening with JFree, and don't think that all these 1.0.x releases make much of a difference as far as cewolf is concerned. If you see anything in the 1.0.x release notes that you think would make sense for cewolf to support, feel free to contact me about it.

[Ulf Dittmer]

A new version of cewolf has been released that incorporates numerous improvements, amongst them:

Tooltips now work in IE 8.

Labels and arrows (so-called annotations) can be added to X/Y and category charts using a postprocessor.

StackedXYAreaRenderer, StackedXYAreaRenderer2 and StackedHorizontalBar3D charts can be created.

Instead of a single axisinteger attribute that applies to both axes, separate xaxisinteger and yaxisinteger attributes have been introduced. This is an incompatible change. If you were using axisinteger before, you need to change this to use one or both of the new attributes.

See the "Java web charts" link in my signature for where to get it.

[Ulf Dittmer]

I've put out a new version that adds xticklabelsvisible, yticklabelsvisible, xtickmarksvisible and ytickmarksvisible attributes to the chart tag. These can be used to hide tick marks and tick labels on both X and Y axes.

[Ulf Dittmer]

Recent releases have made some improvements to the BarRendererProcessor, which can now display item labels (i.e., their values) in a user-defined color.

The chart tag has new attributes plotbordervisible and plotbordercolor to control whether the plot border is shown, and if so, in which color. This is analogous to the bordervisible and bordercolor attribute for the chart border.

The LineRendererProcessor (used for spline, scatter and XY plots) can highlight individual points based on a user-supplied expression/condition.

[Ulf Dittmer]

To anyone who's watching this topic: My unoffical cewolf distribution has now been migrated over to SourceForge; see https://coderanch.com/t/502955/ba/Cewolf-released for the details.