February 2009 - logback-dev

[JIRA] Created: (LBCORE-68) Add a pattern resolver to <file> property of FileAppnder
by Nicolas Giraud (JIRA) 03 Feb '09

03 Feb '09

Add a pattern resolver to <file> property of FileAppnder -------------------------------------------------------- Key: LBCORE-68 URL: http://jira.qos.ch/browse/LBCORE-68 Project: logback-core Issue Type: New Feature Components: Appender, Joran Affects Versions: 0.9.11 Environment: Ubuntu 8.04, J2SE 6 Reporter: Nicolas Giraud Assignee: Logback dev list Following discussion on the mailing list, it would be very convenient to be able to use patterns in the filename of a FileAppender. My initial expectation was to be able to do something like: <appender name="myFileAppender" class="ch.qos.logback.core.FileAppender"> <file>${logFolder}/SomePrefix.%d.someExt</file> [...] </appender> where %d would be substituted by the current date. However Ralph Goers, when replying to my question on the mailing list, suggested a more flexibl approach: <appender name="myFileAppender" class="ch.qos.logback.core.FileAppender"> <File resolver="com.mycorp.logback.MyPatternResolver">someName.%{host}.%{datetime}.log</File> [...] </appender> with MyPatternResolver implementing an interface like: package ch.qos.logback.core.pattern; public interface Resolver { String resolve(String pattern); } Providing a default implementation allowing to generate timestamp, use system properties, would be nice too. Currently this can be done programmatically, but it would be most convenient to have the possibility to do this using the Joran configurator. Best regards, Nicolas -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://jira.qos.ch/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

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[JIRA] Created: (LBCORE-85) Allow configuration of timezone with file name pattern
by Neil Lott (JIRA) 03 Feb '09

03 Feb '09

Allow configuration of timezone with file name pattern ------------------------------------------------------ Key: LBCORE-85 URL: http://jira.qos.ch/browse/LBCORE-85 Project: logback-core Issue Type: Bug Components: Appender Affects Versions: 0.9.14 Environment: Any Reporter: Neil Lott Assignee: Logback dev list <rollingPolicy class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy"> <FileNamePattern>/usr/local/neil/logs/msa-mdn-%i-%d{yyyyMMdd-HHmmss}.log</FileNamePattern> <MinIndex>1</MinIndex> <MaxIndex>5</MaxIndex> </rollingPolicy> In this case the filename pattern %d it would be nice to allow configuration of timezone somehow in the pattern. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://jira.qos.ch/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

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Instant Messenger appender for logback?
by Thorbjørn Ravn Andersen 02 Feb '09

02 Feb '09

Hi. Just to hear if anybody has yet written an Instant Messenger logback appender? I think that the most robust backend would be Jabber so that would be preferred. If not, I'll probably have a go at writing one with the Smack library :) -- Thorbjørn Ravn Andersen "...plus... Tubular Bells!"

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svn commit: r2138 - logback/trunk/logback-core/src/main/java/ch/qos/logback/core/util
by noreply.ceki＠qos.ch 02 Feb '09

02 Feb '09

Author: ceki Date: Mon Feb 2 23:40:27 2009 New Revision: 2138 Modified: logback/trunk/logback-core/src/main/java/ch/qos/logback/core/util/StatusPrinter.java Log: - printInCaseOfErrorsOrWarnings should print ERRORS not just WARNings Modified: logback/trunk/logback-core/src/main/java/ch/qos/logback/core/util/StatusPrinter.java ============================================================================== --- logback/trunk/logback-core/src/main/java/ch/qos/logback/core/util/StatusPrinter.java (original) +++ logback/trunk/logback-core/src/main/java/ch/qos/logback/core/util/StatusPrinter.java Mon Feb 2 23:40:27 2009 @@ -50,7 +50,7 @@ ps.println("WARN: Context named \"" + context.getName() + "\" has no status manager"); } else { - if (sm.getLevel() == ErrorStatus.WARN) { + if (sm.getLevel() == ErrorStatus.WARN || (sm.getLevel() == ErrorStatus.ERROR) ) { print(sm); } } @@ -112,9 +112,9 @@ private static void buildStrFromStatusList(StringBuilder sb, List<Status> statusList) { - Iterator it = statusList.iterator(); - while (it.hasNext()) { - Status s = (Status) it.next(); + if(statusList == null) + return; + for(Status s : statusList) { buildStr(sb, "", s); } }

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svn commit: r2137 - in logback/trunk: logback-core/src/main/java/ch/qos/logback/core/joran/action logback-examples/src/main/java/chapter10/calculator logback-examples/src/main/java/chapter10/helloWorld logback-examples/src/main/java/chapter10/implicit logback-site/src/site/pages/manual
by noreply.ceki＠qos.ch 02 Feb '09

02 Feb '09

Author: ceki Date: Mon Feb 2 23:16:18 2009 New Revision: 2137 Added: logback/trunk/logback-examples/src/main/java/chapter10/helloWorld/readme.txt Modified: logback/trunk/logback-core/src/main/java/ch/qos/logback/core/joran/action/NestedComplexPropertyIA.java logback/trunk/logback-examples/src/main/java/chapter10/calculator/ComputationAction2.java logback/trunk/logback-examples/src/main/java/chapter10/calculator/calculator3.xml logback/trunk/logback-examples/src/main/java/chapter10/calculator/readme.txt logback/trunk/logback-examples/src/main/java/chapter10/implicit/PrintMe.java logback/trunk/logback-examples/src/main/java/chapter10/implicit/PrintMeImplicitAction.java logback/trunk/logback-examples/src/main/java/chapter10/implicit/implicit1.xml logback/trunk/logback-examples/src/main/java/chapter10/implicit/readme.txt logback/trunk/logback-site/src/site/pages/manual/menu.js logback/trunk/logback-site/src/site/pages/manual/onJoran.html Log: Ongoing work on LBSITE-25 Modified: logback/trunk/logback-core/src/main/java/ch/qos/logback/core/joran/action/NestedComplexPropertyIA.java ============================================================================== --- logback/trunk/logback-core/src/main/java/ch/qos/logback/core/joran/action/NestedComplexPropertyIA.java (original) +++ logback/trunk/logback-core/src/main/java/ch/qos/logback/core/joran/action/NestedComplexPropertyIA.java Mon Feb 2 23:16:18 2009 @@ -67,7 +67,6 @@ // we only push action data if NestComponentIA is applicable case AS_COMPLEX_PROPERTY_COLLECTION: case AS_COMPLEX_PROPERTY: - // addInfo("was deemed applicable for " + pattern); IADataForComplexProperty ad = new IADataForComplexProperty(parentBean, aggregationType, nestedElementTagName); actionDataStack.push(ad); Modified: logback/trunk/logback-examples/src/main/java/chapter10/calculator/ComputationAction2.java ============================================================================== --- logback/trunk/logback-examples/src/main/java/chapter10/calculator/ComputationAction2.java (original) +++ logback/trunk/logback-examples/src/main/java/chapter10/calculator/ComputationAction2.java Mon Feb 2 23:16:18 2009 @@ -21,7 +21,7 @@ /** * ComputationAction2 will print the result of the compuration made by - * children elements but only if the compuration itself is named, that is if the + * children elements but only if the computation itself is named, that is if the * name attribute of the associated computation element is not null. In other * words, anonymous computations will not print their result. * @@ -41,7 +41,7 @@ * saved by one begin() will be consumed only by the matching end() method. * * Note that in the vast majority of cases there is no need to resort to a - * separate stack for each variable. The situation of successibe begin() + * separate stack for each variable. The situation of successive begin() * invocations can only occur if: * * 1) the associated pattern contains a wildcard, i.e. the * character Modified: logback/trunk/logback-examples/src/main/java/chapter10/calculator/calculator3.xml ============================================================================== --- logback/trunk/logback-examples/src/main/java/chapter10/calculator/calculator3.xml (original) +++ logback/trunk/logback-examples/src/main/java/chapter10/calculator/calculator3.xml Mon Feb 2 23:16:18 2009 @@ -1,10 +1,8 @@ -<?xml version="1.0" encoding="UTF-8" ?> -<!DOCTYPE computation> - +  + --> <computation name="toto"> <computation> Modified: logback/trunk/logback-examples/src/main/java/chapter10/calculator/readme.txt ============================================================================== --- logback/trunk/logback-examples/src/main/java/chapter10/calculator/readme.txt (original) +++ logback/trunk/logback-examples/src/main/java/chapter10/calculator/readme.txt Mon Feb 2 23:16:18 2009 @@ -1,17 +1,7 @@ -+------------------------------+ -| | -| Joran Examples | -| | -| Calculator | -| | -+------------------------------+ +This directory contains the the calculator example. It shows how Actions can +collaborate in order to accomplish a simple computation. -This directory contains the the calculator example. +For further information, please refer to -It shows how Actions can collaborate in order to accomplish a simple -computation. - -For more in-depth informations about this example, please visit: - -http://logback.qos.ch/manual/joran.html#calculator + http://logback.qos.ch/manual/onJoran.html#calculator Added: logback/trunk/logback-examples/src/main/java/chapter10/helloWorld/readme.txt ============================================================================== --- (empty file) +++ logback/trunk/logback-examples/src/main/java/chapter10/helloWorld/readme.txt Mon Feb 2 23:16:18 2009 @@ -0,0 +1,6 @@ +The example illustrates the minimal plumbing required for using Joran. + +For further explanations, please refer to + + http://logback.qos.ch/manual/onJoran.html#helloWorld + Modified: logback/trunk/logback-examples/src/main/java/chapter10/implicit/PrintMe.java ============================================================================== --- logback/trunk/logback-examples/src/main/java/chapter10/implicit/PrintMe.java (original) +++ logback/trunk/logback-examples/src/main/java/chapter10/implicit/PrintMe.java Mon Feb 2 23:16:18 2009 @@ -1,7 +1,7 @@ /** * Logback: the generic, reliable, fast and flexible logging framework. * - * Copyright (C) 1999-2006, QOS.ch + * Copyright (C) 2000-2009, QOS.ch * * This library is free software, you can redistribute it and/or modify it under * the terms of the GNU Lesser General Public License as published by the Free @@ -14,54 +14,46 @@ import java.util.List; import java.util.Map; -import chapter10.SimpleConfigurator; import ch.qos.logback.core.Context; import ch.qos.logback.core.ContextBase; import ch.qos.logback.core.joran.action.Action; import ch.qos.logback.core.joran.action.ImplicitAction; -import ch.qos.logback.core.joran.spi.JoranException; import ch.qos.logback.core.joran.spi.Pattern; import ch.qos.logback.core.util.StatusPrinter; - +import chapter10.SimpleConfigurator; /** - * This example illustrates the usage of implcit actions. + * This example illustrates the usage of implicit actions. * - * The crucial point to remember about implicit actions is that they - * are not associated with a pattern. Moreover, they are added directly to - * a Joran Interpreter instead of a rule store. + * Keep in mind that implicit actions are not associated with any specific + * pattern. Moreover, they are added directly to a Joran Interpreter instead of + * a rule store. * * @author Ceki Güulcü */ public class PrintMe { - - + public static void main(String[] args) throws Exception { Context context = new ContextBase(); - + Map<Pattern, Action> ruleMap = new HashMap<Pattern, Action>(); - // we start with the rule for the top-most (root) element ruleMap.put(new Pattern("*/foo"), new NOPAction()); - + // Add an implicit action. List<ImplicitAction> iaList = new ArrayList<ImplicitAction>(); - // --------------------------+ - // Add an implicit action. | - // --------------------------+ iaList.add(new PrintMeImplicitAction()); - - SimpleConfigurator simpleConfigurator = new SimpleConfigurator(ruleMap, iaList); + SimpleConfigurator simpleConfigurator = new SimpleConfigurator(ruleMap, + iaList); + // link the configurator with its context simpleConfigurator.setContext(context); try { - simpleConfigurator.doConfigure(args[0]); - } catch (JoranException e) { - // Print any errors that might have occured. - StatusPrinter.print(context); + simpleConfigurator.doConfigure(args[0]); + } catch (Exception e) { + StatusPrinter.print(context); } - } } Modified: logback/trunk/logback-examples/src/main/java/chapter10/implicit/PrintMeImplicitAction.java ============================================================================== --- logback/trunk/logback-examples/src/main/java/chapter10/implicit/PrintMeImplicitAction.java (original) +++ logback/trunk/logback-examples/src/main/java/chapter10/implicit/PrintMeImplicitAction.java Mon Feb 2 23:16:18 2009 @@ -1,13 +1,12 @@ /** - * Logback: the reliable, fast and flexible logging library for Java. + * Logback: the generic, reliable, fast and flexible logging framework. * - * Copyright (C) 1999-2006, QOS.ch + * Copyright (C) 2000-2009, QOS.ch * * This library is free software, you can redistribute it and/or modify it under * the terms of the GNU Lesser General Public License as published by the Free * Software Foundation. */ - package chapter10.implicit; import org.xml.sax.Attributes; @@ -16,29 +15,26 @@ import ch.qos.logback.core.joran.spi.InterpretationContext; import ch.qos.logback.core.joran.spi.Pattern; - - /** - * - * A rather trivial implicit action which is applicable as soon as an - * element has a printme attribute set to true. - * + * + * A rather trivial implicit action which is applicable if an element has a + * printme attribute set to true. + * * @author Ceki Gülcü */ public class PrintMeImplicitAction extends ImplicitAction { - - public boolean isApplicable( - Pattern pattern, Attributes attributes, InterpretationContext ec) { + + public boolean isApplicable(Pattern pattern, Attributes attributes, + InterpretationContext ec) { String printmeStr = attributes.getValue("printme"); return Boolean.valueOf(printmeStr).booleanValue(); } public void begin(InterpretationContext ec, String name, Attributes attributes) { - System.out.println("Element ["+name+"] asked to be printed."); - } + System.out.println("Element [" + name + "] asked to be printed."); + } - public void end(InterpretationContext ec, String name) { } } Modified: logback/trunk/logback-examples/src/main/java/chapter10/implicit/implicit1.xml ============================================================================== --- logback/trunk/logback-examples/src/main/java/chapter10/implicit/implicit1.xml (original) +++ logback/trunk/logback-examples/src/main/java/chapter10/implicit/implicit1.xml Mon Feb 2 23:16:18 2009 @@ -1,9 +1,6 @@ -<?xml version="1.0" encoding="UTF-8" ?> -<!DOCTYPE foo> - <foo> -  +  <xyz printme="true"> <abc printme="true"/> </xyz> @@ -17,7 +14,7 @@  <foo printme="true"/> Modified: logback/trunk/logback-examples/src/main/java/chapter10/implicit/readme.txt ============================================================================== --- logback/trunk/logback-examples/src/main/java/chapter10/implicit/readme.txt (original) +++ logback/trunk/logback-examples/src/main/java/chapter10/implicit/readme.txt Mon Feb 2 23:16:18 2009 @@ -1,17 +1,7 @@ -+------------------------------+ -| | -| Joran Examples | -| | -| Implicit | -| | -+------------------------------+ -This directory contains the implicit action example. +This directory contains an example illustrating implicit actions. -It shows how to use implicit actions, which do not require an explicit -pattern. - -For more in-depth informations about this example, please visit: - -http://logback.qos.ch/manual/joran.html#implicit +For further information, please refer to + http://logback.qos.ch/manual/onJoran.html#implicit + \ No newline at end of file Modified: logback/trunk/logback-site/src/site/pages/manual/menu.js ============================================================================== --- logback/trunk/logback-site/src/site/pages/manual/menu.js (original) +++ logback/trunk/logback-site/src/site/pages/manual/menu.js Mon Feb 2 23:16:18 2009 @@ -9,4 +9,4 @@ document.write('<a href="mdc.html">Ch7: Mapped Diagnostic Contexts</a>'); document.write('<a href="loggingSeparation.html">Ch8: Logging Separation</a>'); document.write('<a href="jmxConfig.html">Ch9: JMX Configurator</a>'); -document.write('<a href="onJoran.html">Ch9: Joran</a>'); +document.write('<a href="onJoran.html">Ch10: Joran</a>'); Modified: logback/trunk/logback-site/src/site/pages/manual/onJoran.html ============================================================================== --- logback/trunk/logback-site/src/site/pages/manual/onJoran.html (original) +++ logback/trunk/logback-site/src/site/pages/manual/onJoran.html Mon Feb 2 23:16:18 2009 @@ -305,7 +305,7 @@ <literal value="3"/> </computation> - In the <a href="../xref/chapter3/calculator/Calculator1.html"> + In the <a href="../xref/chapter10/calculator/Calculator1.html"> <code>Calculator1</code></a> application, we declare various parsing rules (patterns and actions) collaborating together to compute a result based on the contents of an XML document. @@ -326,16 +326,43 @@ <ul> - <li>The <a - href="../xref/chapter3/calculator/ComputationAction1.html"> - <code>ComputationAction1</code></a> class' <code>begin()</code> - method is called</li> - <li>The <a href="../xref/chapter3/calculator/LiteralAction.html"> - <code>LiteralAction</code></a> class' <code>begin()</code> and <code>end()</code> - methods are called</li> - <li>The <a href="../xref/chapter3/calculator/ComputationAction1.html"> - <code>ComputationAction1</code></a> class' <code>end()</code> method - is called</li> + <li>The start event corresponding to the <computation> + element translates into the current pattern + "/computation". Since in the <a + href="../xref/chapter10/calculator/Calculator1.html"> + <code>Calculator1</code></a> application we associated the + pattern "/computation" with a + <a + href="../xref/chapter10/calculator/ComputationAction1.html"> + <code>ComputationAction1</code></a> instance, the + <code>begin()</code> method of that + <code>ComputationAction1</code> instance is invoked. + </li> + + <li>The start event corresponding to the <literal> + element translates into the current pattern + "/computation/literal". Given the association of the + "/computation/literal" pattern with a + <a + href="../xref/chapter10/calculator/LiteralAction.html"> + <code>LiteralAction</code></a> instance, the + <code>begin()</code> method of that <code>LiteralAction</code> + instance is called. + </li> + + <li>By the same token, the end event corresponding to the + <literal> element triggers the invocation of the + <code>end</code>() method of the same <code>LiteralAction</code> + instance. + </li> + + + <li>Similarly, the event corresponding to the end of + <computation> element triggers the invocation the + <code>end()</code> method of the <code>ComputationAction1</code> + same instance. + + </li> </ul> What is interesting here is the way actions collaborate. The @@ -349,14 +376,12 @@  - The calculator2.xml file is a bit more complex, but - much more interesting. - - It contains the following elements: + The next example, calculator2.xml file is a bit more + complex, but also more interesting. Example 3.: Calculator configuration file - (logback-examples/src/main/java/chapter3/calculator/calculator2.xml) + (logback-examples/src/main/java/chapter10/calculator/calculator2.xml) <div class="source"><pre><computation name="toto"> <literal value="7"/> <literal value="3"/> @@ -365,25 +390,38 @@ <multiply/> </computation></pre></div> - Here, there are obviously more actions that will be part of the - computation. + + As in the previous example, in response to the <literal> + element,the appropriate <a + href="../xref/chapter10/calculator/LiteralAction.html"> + <code>LiteralAction</code></a> instance will push an integer, + corresponding to the value attribute, at the top of the + interpretation context's object stack. In this example, that is + calculator2.xml, the values are 7 and 3. In response to the + <add> element, the appropriate <a + href="../xref/chapter10/calculator/AddAction.html"><code>AddAction</code></a> + will pop two previously pushed integers, compute their sum and push + the result, i.e. 10 (=7+3), at the top of the interpretation + context's stack. The next literal element will cause LiteralAction + to push an integer with value 3 at the top of the stack. In response + to the <multiply> element, the appropriate <a + href="../xref/chapter10/calculator/MultiplyAction.html"><code>MultiplyAction</code></a> + will pop two previously pushed integers, i.e. 10 and 3, and compute + their product. It will push the result, i.e. 30, at the top of the + stack. At the very end, in reponse to the end event corresponding to + the <;/computation> tag, the ComputationAction1 will print the + object at the top of the stack. Thus, running: - When called, the <a - href="../xref/chapter3/calculator/AddAction.html"> - <code>AddAction</code></a> class will remove the two integers at the - bottom of the stack, add them and push the resulting integer at the - top of the stack, for further use. - - Later in the computation, the <a - href="../xref/chapter3/calculator/MultiplyAction.html"> - <code>MultiplyAction</code></a> class will be called. It will take - the last two integers from the stack, multiply them and push the - result in the stack. - - We have here two examples of action whose <code>begin()</code> - method behaves in a certain, predictable way, but whose - <code>end()</code> methods are empty. + java chapter10.calculator.Calculator1 src/main/java/chapter10/calculator/calculator2.xml + + will yield + + The computation named [toto] resulted in the value 30 + + +  <h3><a name="implicit" href="#implicit">Implicit actions</a></h3> - The rules defined thus far are called explicit rules because they - require an explicit pattern, hence fixing the tag name of the - elements for which they apply. - - - In highly extensible systems, the number and type of components - to handle are innumerable so that it would become very tedious or - even impossible to list all the applicable patterns by name. + The rules defined thus far are called explicit actions because an + pattern/action association could be found in the rule store for the + current element. However, in highly extensible systems, the number + and type of components can be so large so as to make it very tedious + to associate an explicit action for all patterns. At the same time, even in highly extensible systems one can - observe well-defined patterns linking the various parts - together. Implicit rules come in very handy when processing - components composed of sub-components unknown ahead of time. For + observe recurrent rules linking various parts together. Assuming we + could identify such rules, we could process components composed of + sub-components unknown at compilation time (of logback). For example, Apache Ant is capable of handling tasks which contain tags - unknown at compile time by looking at methods whose names start with - add, as in <code>addFile</code>, or - <code>addClassPath</code>. When Ant encounters an embedded tag - within a task, it simply instantiates an object that matches the - signature of the task class' add method and attaches the resulting - object to the parent. + unknown at compile time, simply by inspecting the component for + methods whose names start with add, as in + <code>addFile</code>, or <code>addClassPath</code>. When Ant + encounters an embedded tag within a task, it simply instantiates an + object that matches the signature of the task class' add method and + attaches the resulting object to the parent. - Joran includes similar capability in the form of implicit - actions. Joran keeps a list of implicit actions which can be applied - if no explicit pattern matches the current XML element. However, + Joran supports similar capability in the form of implicit + actions. Joran keeps a list of implicit actions which are applied if + no explicit pattern could match the current pattern. However, applying an implicit action may not be always appropriate. Before - executing the implicit action, Joran asks an implicit action whether - it is appropriate in the current context. Only if the action replies - affirmatively does Joran interpreter invoke the (implicit) - action. This extra step makes it possible to support multiple - implicit actions or obviously none, if no implicit action is - appropriate for a given situation. + executing the implicit action, Joran asks a given implicit action + whether it is appropriate in the current situation. Only if the + action replies in the affirmative does the Joran configurator invoke + the (implicit) action. Note that this extra step makes it possible + to support multiple implicit actions for or possibly none, if no + implicit action is appropriate for a given situation. - For example, the <a - href="../xref/ch/qos/logback/core/joran/action/NestedComponentIA.html"> - <code>NestedComponentIA</code></a> extending <a - href="../xref/ch/qos/logback/core/joran/action/ImplicitAction.html"> - <code>ImplicitAction</code></a> , will instantiate the class - specified in a nested component and attach it to the parent - component by using setter method of the parent component and the - nested element's name. Under certain circumstances, a nested action - needs to be applied to an element say <a> and also to another - element nested within <a>. The current implementation of - <code>NestedComponentIA</code> is capable of handling multiply - nested elements requiring intervention by the same implicit action. + You can create and register a custom implicit action as + illustrated in the next example contained within the + logback-examples/src/main/java/chapter10/implicit folder. - Both <code>ImplicitAction</code> and - <code>NestedComponentIA</code> are located in the - <code>ch.qos.logback.core.joran.action</code> package. + The <a + href="../xref/chapter10/implicit/PrintMe.html"><code>PrintMe</code></a> + application associates an <a + href="../xref/chapter3/implicit/NOPAction.html"> + <code>NOPAction</code></a> instance with the pattern "*/foo", that + is any element named as "foo". As its name indicates, the + <code>begin</code>() and <code>end</code>() methods of + <code>NOPAction</code> are empty. The <code>PrintMe</code> + application also registers an instance of <a + href="../xref/chapter10/implicit/PrintMeImplicitAction.html">PrintMeImplicitAction</a> + in its list of implicit actions. The + <code>PrintMeImplicitAction</code> is applicable for any element + which has a printme attribute set to + true. See the isApplicable method in + <code>PrintMeImplicitAction</code>. The <code>begin</code>() method + of <code>PrintMeImplicitAction</code> prints the name of the current + element on the console. - Refer to the - logback-examples/src/main/java/joran/implicit directory for - an example of an implicit action. - - - In that directory, you will find two actions classes, one xml - file and one class containing the setup of Joran. - - The <a href="../xref/chapter3/implicit/NOPAction.html"> - <code>NOPAction</code></a> class does nothing. It is used to set the - context of the foo element, using this line: - - ruleStore.addRule(new Pattern("*/foo"), new NOPAction()); - - After that, the implicit action, namely <a - href="../xref/chapter3/implicit/PrintMeImplicitAction.html"> - <code>PrintMeImplicitAction</code></a>, is added to the - <code>RuleStore</code>. This is done by simply adding a new instance - of the action to the <code>Joran interpreter</code> - - ji.addImplicitAction(new - PrintMeImplicitAction()); - - When called, the <code>isApplicable()</code> method of - <code>PrintMeImplicitAction</code> checks the value of the - printme attribute. If the value is <code>true</code>, the - implicit action is applicable: its <code>begin()</code> method will - be called. - - The implicit1.xml file contains the following lines: + The XML document implicit1.xml is designed to illustrate + how implicit actions come into play. Example 3.: Usage of implicit rules - (logback-examples/src/main/java/chapter3/implicit/implicit1.xml) -<div class="source"><pre><foo> - + (logback-examples/src/main/java/chapter10/implicit/implicit1.xml) + <foo> <xyz printme="true"> <abc printme="true"/> </xyz> @@ -511,29 +523,70 @@ <foo printme="true"/> -</foo></pre></div> +</foo> + + Running - As you can see, the first element will be printed, since it has a - printme attribute, which bears the value - <code>true</code>. + java chapter10.implicit.PrintMe src/main/java/chapter10/implicit/implicit1.xml + yields: - The second element will not be printed, because no printme attibute is present. + Element [xyz] asked to be printed. +Element [abc] asked to be printed. + + Given that <code>NOPAction</code> instance is explicitly + associated with the "*/foo" pattern, the + <code>PrintMeImplicitAction</code> is never triggered for any of the + <foo> elements. For other elements, the + <code>isApplicable</code> method of + <code>PrintMeImplicitAction</code> is invoked. It will return true + only for elements having a printme + attribute set to true, namely the first <xyz> element (but not + the second) and the <abc> element. This explains the output shown + above (previous paragraph). + + + <h3><a name="iaPractice" href="#iaPractice">Implicit actions in + practice</a></h3> + + The respective Joran configurators of logback-classic and + logback-access include just two implicit actions, namely <a + href="../xref/ch/qos/logback/core/joran/action/NestedBasicPropertyIA.html"> + <code>NestedComplexPropertyIA</code></a> and <a + href="../xref/ch/qos/logback/core/joran/action/NestedComplexPropertyIA.html"> + <code>NestedComplexPropertyIA</code></a>. + - The last element will not be printed, although the required - attribute is present. This is because implicit rules are called - only if no explicit rules are defined. Since we added a - <code>NOPAction</code> with the */foo pattern, it will be - used instead of the <code>PrintMeImplicitAction</code>. + + <code>NestedBasicPropertyIA</code> is applicable for any property + whose type, is a primitive type, or equivalent object type in the + <code>java.lang</code> package, an enumeration type, or any type + adhering to the "valueOf" convention. A class is said to adhere to + the "valueOf" convention if it contains a static method named + <code>valueOf</code>() taking a <code>java.lang.String</code> as + parameter and returning an instance of the type in question. + + + <code>NestedComplexPropertyIA</code> action is applicable in the + remaining cases where <code>NestedBasicPropertyIA</code> is not + applicable. In other words, <code>NestedComplexPropertyIA</code> is + a last resort, catch-all, implicit action. It will + - Running the example yields the following output: + For example, the <a + href="../xref/ch/qos/logback/core/joran/action/NestedComplexPropertyIA.html"> + <code>NestedComplexPropertyIA</code></a> extending <a + href="../xref/ch/qos/logback/core/joran/action/ImplicitAction.html"> + <code>ImplicitAction</code></a>, will instantiate the class + specified in a nested component and attach it to the parent + component by using setter method of the parent component and the + nested element's name. Under certain circumstances, a nested action + needs to be applied to an element say <a> and also to another + element nested within <a>. The current implementation of + <code>NestedComponentIA</code> is capable of handling multiply + nested elements requiring intervention by the same implicit action. + -<div class="source"><pre>Element <xyz> asked to be printed. -Element <abc> asked to be printed. -ERROR in ch.qos.logback.core.joran.spi.InterpretationContext@1c5c1 - no applicable action \ -for <xyz>, current pattern is [/foo/xyz]</pre></div> - The last line was printed because of a call to - <code>StatusPrinter</code> at the end of the main class. <a name="newRule"></a>

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