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Version Date Modified Size Author Changes ... Change note
90 24-Feb-2016 11:06 9 KB Albrecht Striffler to previous
89 15-May-2014 09:33 9 KB Volker Belli to previous | to last
88 15-May-2014 09:32 9 KB Volker Belli to previous | to last
87 15-May-2014 09:30 9 KB Volker Belli to previous | to last
86 21-Jun-2013 15:09 8 KB Jochen Reutelshöfer to previous | to last
85 21-Jun-2013 15:08 8 KB Jochen Reutelshöfer to previous | to last
84 21-Dec-2012 16:15 7 KB Jochen Reutelshöfer to previous | to last
83 21-Dec-2012 16:14 7 KB Jochen Reutelshöfer to previous | to last
82 18-Dec-2012 17:47 7 KB Alex Legler to previous | to last Fix Image link URL
81 17-Dec-2012 21:33 7 KB CarstenWasner to previous | to last

Page References

Incoming links Outgoing links
Developer FAQ
Developer FAQ

Version management

Difference between version and

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This page is supposed to help you getting started with the development of KnowWE. Feel free to add your solutions to this page. If you don't find the information you need here, you can post it in the [Forum|http://sourceforge.net/projects/knowwe/forums].
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[{TableOfContents title='Frequently Asked Questions'}]
!!! FAQ
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What... ? and Why...? Questions
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!!General
This Page is supposed to help you getting started with the development of KnowWE. Feel free to add your Solutions to this page. If you don't find the Informations you need here, you can post it in the forum.
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[{TableOfContents }]
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!What is a Plugin?
!!Creating new projects
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A plugin is a module extending KnowWE's functionality. A plugin needs a [plugin.xml|Meaning of plugin.xml] file defining the extensions for this plugin.
Every new project has to be allocated to one of the three main repositories: __d3web-core, d3web-KnowWE or Research.__
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!Creating the project in Eclipse
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!What is an Extension?
* Do a right click on the main project (one of the three projects mentioned above) → New → Other…. In the window, select "Maven Module"
* Check the checkbox called "Skip Archetype selection", give the project a name and hit Next.
* Enter a human-readable name into the field "Name", fill in "Description" as needed.
* Click "Finish".
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An extension implements the plugin's functionality using an extension point. For further definition and usage instructions see [this page|How-To Extension Points]..
Now you will see the new project in the Eclipse Project Explorer. Now you can start creating or copying source files. Using the __UTF-8 encoding__ is __mandatory.__
! License header
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!What is the Scope of an Extension?
A scope is an selector of a specific subset of KDOM nodes. Its selection is based on the type of the KDOM nodes itself as well as on the type of the KDOM node's anchestors. It can be compared a little bit to the css selectors.
The scope is a path of those KDOM node types that should be matched/selected. The path can be relative (anywhere in the KDOM tree) or root based. Specific path wildcards as "*" and "**" are allowed. The different kinds of scopes and their usage are explained [here|How-To Extension Points].
!What is an Extension Point?
An extension point has a specific type, for example ''Action, TagHandler, TypeHandler'' or ''EventListener''. The defined extension point specifies that each extension has to give values for class, name, description, version, and priority. This has to be defined by each extension point; an extension point further can require additional value, for example the specification of a file name.
For further definition and usage instructions see [this page|How-To Extension Points].
!!Getting Started
!Why isn't Plugin X included in my build?
[{Image src='attach/Developer%20FAQ/m2eclipse-plugins.png' width='232' height='202' align='right' link='attach/Developer%20FAQ/m2eclipse-plugins.png'}]
You need to enable the plug-ins you want to build into KnowWE when using Eclipse. Here's how:
Open your Run Configuration for the KnowWE build and add parameters for the plug-ins you want to have in the goals section.
For instance: You want to enable the Comment plug-in. Here, you have to add a {{comment-plugin}} parameter. List all the profile names for the Plug-ins you want to add in the Profiles Section and build KnowWE.
See the screenshot on the right for another example.
! What do I have to mind about the license?
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You can do this automatically by adding [codetemplates.xml] in Eclipse: ''Window'' -> ''Preferences'' -> ''Java'' -> ''Code Style'' -> ''Code Templates''
!First check-in
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! What is important about the first check-in?
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!!Selecting plugins to build
[{Image src='FAQ/m2eclipse-plugins.png' width='232' height='202' align='right' link='http://d3webwiki.informatik.uni-wuerzburg.de/attach/FAQ/m2eclipse-plugins.png'}]
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!! Plugin-Development
You need to enable the plug-ins you want to build into KnowWE when using Eclipse. Here's how:
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Open your Run Configuration for the KnowWE build and add parameters for the plug-ins you want to have.
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!What do I need to do after I change a .java file?
For instance: You want to enable the Comment plug-in. Here, you have to add a {{comment-plugin}} parameter. You can set it to an arbitrary value ('true' for instance).
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Usually you only have to refresh your browser page. Hot Code Replacement makes your changes effective at runtime.
See the screenshot on the right for another example.
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!!Eclipse does not catch breakpoints
Update your JDK to at least Version 6, Update 17.
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!I'm done editing. How to make my changes permanent?
<tags>workspace problems FAQ </tags>
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You don't have to worry that you changes will be lost after you shut down KnowWE. To make the changes effective for the next restart, you have to perform Maven install on KnowWE-App.
!!java.util.MissingResourceException: Can't find bundle for base name...
Happens after cleaning the workspace.
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Solution: For each of the two maven super projects (d3web, d3web-KnowWE), select the project, right click on it, "Run as...", "Maven package".
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!Hot Code Replacement failed. What to do?
!!Offline Build (if Artifactory is not available or you have no Internet connection)
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Sometimes, especially when doing major changes to a .java file, Hot Code Replacement fails. In this case you have to
*Quit Tomcat
*Perform a Maven install on KnowWE-App and
*Start Tomcat again.
Create a second runtime configuration for building KnowWE, just like shown here: [http://d3webwiki.informatik.uni-wuerzburg.de/Wiki.jsp?page=Workspace#section-Workspace-CreateARunConfigurationForBuildingTheWiki], just check the "Offline" checkbox. __Note__: Do not enable this option for your regular build, only use it if Artifactory is down or you are not connected to the internet!
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!! Problems with Umlauts
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!What do I need to do after I change a Non-Java file?
Tomcat can be configured in UTF-8 to handle Umlauts correctlty. Look at [http://www.jspwiki.org/wiki/BugProblemsWithGermanUmlaute]
//End Old
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Unfortunately, there is no Hot Code Replacement for Non-Java files. However, there is a [How-To for developing Javascript at runtime|How-To Develop JavaScript in KnowWE], which may be useful for you.
What... ? and Why...? Questions\\
Coordinate with How-To
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How to make changes to Non-Java files effective:
*Quit Tomcat
*Perform Maven Install on your plugin aswell as KnowWE-App
*Restart Tomcat
%%Todo
Set this page up, add table of contents and some introductory words. Every question is its own small headline with the answer directly below.
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@user: Christian Henniger
%
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!Tomcat successfully starts, but the wiki pages are not loaded. What to do?
%%Todo
Developer FAQ
* Define questions
* Answer questions, get the information if unkown
* Get and update/improve stuff from old pages: [http://d3webwiki.informatik.uni-wuerzburg.de/Wiki.jsp?page=FAQ]
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This can happen when you perform a Maven install while Tomcat is still running. To fix this, you have to follow these steps:
*Right click on KnowWE-App in Eclipse and select
@user: Christian Henniger
%
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{{{Tomcat > Update Tomcat Context}}}
%%Todo
Developer FAQ
* Some examples:
** What do I need do mvn install, after I change a java file or non-java file?
** Tomcat starts, but wikipages are not loaded -> update Tomcat-Context... this happens when mvn installing while tomcat is running...
** What is an plugin, what is an extension, what is an extension point ([http://d3webwiki.informatik.uni-wuerzburg.de/Wiki.jsp?page=Plugins%20and%20Extensions])
** What is the Scope of an extension
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*Start Tomcat
! Why cannot my JUnit tests be executed?
If the message appears 'dependencies/output.txt not found' read further in this [howto|How-To Initialize Plugin Manager for JUnit Tests].
!Can I make a build without a Internet connection?
Create a second runtime configuration for building KnowWE, just like shown here: [http://d3webwiki.informatik.uni-wuerzburg.de/Wiki.jsp?page=Workspace#section-Workspace-CreateARunConfigurationForBuildingTheWiki], just check the "Offline" checkbox. __Note__: Do not enable this option for your regular build, only use it if artifactory is down or you are not connected to the internet!
!!Common Problems
! Why are Umlauts viewed uncorrectly?
Tomcat can be configured in UTF-8 to handle Umlauts correctly. Look at [http://www.jspwiki.org/wiki/BugProblemsWithGermanUmlaute]
!Why does Eclipse not catch breakpoints?
This issue is caused by an outdated JDK. Please update your JDK to the [latest version | http://www.oracle.com/technetwork/java/javaee/downloads/index.html].
!Why do i get a java.util.MissingResourceException: Can't find bundle for base name Exception?
This happens after cleaning the workspace.
For each of the two maven super projects (d3web, d3web-KnowWE), select the project, right click on it, "Run as...", "Maven package".
! INFO: ERROR: Failed to create a Wiki engine: JSPWiki: Unable to load and setup properties from jspwiki.properties.
This is a missleading message display caused by unprecise error handling within jspwiki initialization code. The try-catch does not only include reading of the jspwiki.properties file, but also initialization of plugins/filters, i.e. also entire initialisiation of KnowWE. If you have recently changed code of KnowWE or a KnowWE-Plugin this error __most likely__ has __nothing__ to do with the jspwiki.properties file. It can be any kind of exception happening during KnowWE initialization. After the ''Unable to load and setup properties from jspwiki.properties'' the ''e.getMessage()'' of the actual exception is shown (without stack-trace unfortunately). __Tipp:__ Check the message string to guess what kind of exception it might have been; Consider your latest code changes; if nothing helps start debugging, e.g. in ''Environment.initInstance()''
! Are d3web's Session objects thread-safe for multi-threaded environments?
In general a single d3web session is not thread-safe for write access. Reading contents from the same session with multiple threads is ok. But having an applications where multiple threads simultaneously read/write to a session, they need to be synchronized. Even if there is only one thread that writes to the session, it need to be synchronized with all reading threads. By convention, in d3web this should be done using the "Session"-Object as the semaphore for synchronization. This makes sure that your code will be interoperable with all other applications code (also considering this convention), without being in danger to create deadlocks.
%%prettify
{{{
// put your non d3web-code here
// ...
synchronized (session) {
// your read/write access to the session or blackboard or ... here
// ...
}
}}}
/%
%%tags
FAQ Developer
@user: Daniel Zügner
This page (revision-90) was last changed on 24-Feb-2016 11:06 by Albrecht Striffler Top