condition to check for parser features. Left to others to put into Ant's build.xml.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@277735 13f79535-47bb-0310-9956-ffa450edef68

docs/manual/CoreTasks/conditions.html

@@ -475,6 +475,62 @@ Example:
 
 Sets the default value of the condition to true, then in the script, 
 sets the value to false. This condition always evaluates to "false"
+
+<h4>parsersupports</h4>
+
+<p>Tests whether Ant's XML parser supports a given
+feature or property, as per the SAX/JAXP specifications, by
+attempting to set the appropriate property/feature/</p>
+
+<p>This condition was added in Apache Ant 1.7.</p>
+
+<table border="1" cellpadding="2" cellspacing="0">
+  <tr>
+    <td valign="top"><b>Attribute</b></td>
+    <td valign="top"><b>Description</b></td>
+    <td align="center" valign="top"><b>Required</b></td>
+  </tr>
+  <tr>
+    <td valign="top">property</td>
+    <td valign="top">property to set</td>
+    <td valign="top" align="center">one of property or feature</td>
+  </tr>
+  <tr>
+    <td valign="top">feature</td>
+    <td valign="top">feature to set</td>
+    <td valign="top" align="center">one of property or feature</td>
+  </tr>
+  <tr>
+    <td valign="top">value</td>
+    <td valign="top">string (property) or boolean (feature)</td>
+    <td valign="top" align="center">For property tests, but not for feature tests</td>
+  </tr>
+</table>
+
+<pre>
+&lt;parsersupports feature="http://xml.org/sax/features/namespaces"/&gt;
+</pre>
+Check for namespace support. All SAX2 parsers should have this.
+<pre>
+&lt;or&gt;
+  &lt;parsersupports
+    feature="http://apache.org/xml/features/validation/schema"/&gt;
+  &lt;parsersupports
+    feature="http://java.sun.com/xml/jaxp/properties/schemaSource"/&gt;
+&lt;/or&gt;
+</pre>
+
+Check for XML Schema support.
+
+<pre>
+
+&lt;parsersupports
+  property="http://apache.org/xml/properties/schema/external-noNamespaceSchemaLocation"
+  value="document.xsd"/&gt;
+</pre>
+
+Check for Xerces-specific definition of the location of the no namespace schema.
+
 <hr>
 <p align="center">Copyright &copy; 2001-2005 Apache Software
 Foundation. All rights Reserved.</p>

src/etc/testcases/taskdefs/conditions/parsersupports.xml

@@ -0,0 +1,93 @@
+<project name="parsersupports" >
+<!--
+ * Copyright  2005 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.
+ *
+-->
+
+  <target name="testEmpty">
+    <condition property="empty">
+      <parsersupports />
+    </condition>
+    <fail>Expected failure before here</fail>
+  </target>
+
+  <target name="testBoth">
+    <condition property="both">
+      <parsersupports property="http://bar" feature="http://foo"/>
+    </condition>
+    <fail>Expected failure before here</fail>
+  </target>
+
+  <target name="testNamespaces">
+    <fail>
+    <condition >
+      <not>
+        <parsersupports feature="http://xml.org/sax/features/namespaces"/>
+      </not>
+    </condition>
+      Expected namespace support
+    </fail>
+  </target>
+
+  <target name="testPropertyInvalid">
+    <fail>
+      <condition>
+        <not>
+          <parsersupports
+            property="http://xml.org/sax/properties/declaration-handler"
+            value="undefined"/>
+        </not>
+      </condition>
+      Expected DTD declaration property settable.
+    </fail>
+  </target>
+
+  <target name="testPropertyNoValue">
+    <fail>
+      <condition>
+        <not>
+          <parsersupports
+            property="http://xml.org/sax/properties/declaration-handler"
+              />
+        </not>
+      </condition>
+      Expected no property
+    </fail>
+  </target>
+  
+  <target name="testUnknownProperty">
+    <fail>
+      <condition>
+          <parsersupports property="http://org.apache.ant/something"
+              value="undefined"/>
+      </condition>
+      Expected unsupported property.
+    </fail>
+  </target>
+  
+  <target name="testXercesProperty">
+    <fail>
+      <condition>
+        <not>
+          <parsersupports
+          property="http://apache.org/xml/properties/schema/external-noNamespaceSchemaLocation"
+            value="parsersupports.xml"/>
+        </not>
+      </condition>
+      Expected XSD support on Xerces.
+    </fail>
+  </target>
+  
+</project>

src/main/org/apache/tools/ant/taskdefs/condition/ParserSupports.java

@@ -0,0 +1,150 @@
+/*
+ * Copyright  2005 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.
+ *
+ */
+package org.apache.tools.ant.taskdefs.condition;
+
+import org.apache.tools.ant.ProjectComponent;
+import org.apache.tools.ant.BuildException;
+import org.apache.tools.ant.Project;
+import org.apache.tools.ant.util.JAXPUtils;
+import org.xml.sax.XMLReader;
+import org.xml.sax.SAXNotRecognizedException;
+import org.xml.sax.SAXNotSupportedException;
+
+/**
+ * test for the XML parser supporting a particular feature
+ * @since Ant 1.7
+ */
+public class ParserSupports extends ProjectComponent implements Condition {
+
+    private String feature;
+    private String property;
+    private String value;
+    public static final String ERROR_BOTH_ATTRIBUTES =
+            "Property and feature attributes are exclusive";
+    public static final String FEATURE="feature";
+    public static final String PROPERTY = "property";
+
+    public static final String NOT_RECOGNIZED =
+            " not recognized: ";
+    private static final String NOT_SUPPORTED =
+            " not supported: ";
+    public static final String ERROR_NO_ATTRIBUTES = "Neither feature or property are set";
+    public static final String ERROR_NO_VALUE = "A value is needed when testing for property support";
+
+    /**
+     * Feature to probe for.
+     *
+     * @param feature
+     */
+    public void setFeature(String feature) {
+        this.feature = feature;
+    }
+
+    /**
+     * Property to probe for
+     * @param property
+     */
+    public void setProperty(String property) {
+        this.property = property;
+    }
+
+    /**
+     * Optional value to set.
+     * Converted to a boolean value when setting a property
+     * @param value
+     */
+    public void setValue(String value) {
+        this.value = value;
+    }
+
+
+
+    /**
+     * validate the args, then try to set the feature or property
+     * @return
+     * @throws BuildException
+     */
+    public boolean eval() throws BuildException {
+        if(feature!=null && property!=null) {
+            throw new BuildException(ERROR_BOTH_ATTRIBUTES);
+        }
+        if(feature==null && property==null) {
+            throw new BuildException(ERROR_NO_ATTRIBUTES);
+        }
+        //pick a value that is good for everything
+        if(feature!=null) {
+            return evalFeature();
+        } else {
+            if(value==null) {
+                throw new BuildException(ERROR_NO_VALUE);
+            }
+            return evalProperty();
+        }
+    }
+
+    /**
+     * get our reader
+     * @return a reader
+     */
+    private XMLReader getReader() {
+        JAXPUtils.getParser();
+        return JAXPUtils.getXMLReader();
+    }
+
+    /**
+     * set a feature
+     * @return true if the feature could be set
+     */
+    public boolean evalFeature() {
+        XMLReader reader = getReader();
+        if (value == null) {
+            value = "true";
+        }
+        boolean v= Project.toBoolean(value);
+        try {
+            reader.setFeature(feature,v);
+        } catch (SAXNotRecognizedException e) {
+            log(FEATURE+NOT_RECOGNIZED+feature,Project.MSG_VERBOSE);
+            return false;
+        } catch (SAXNotSupportedException e) {
+            log(FEATURE+NOT_SUPPORTED + feature, Project.MSG_VERBOSE);
+            return false;
+        }
+        return true;
+    }
+
+    /**
+     * set a feature
+     *
+     * @return true if the feature could be set
+     */
+    public boolean evalProperty() {
+        XMLReader reader = getReader();
+        try {
+            reader.setProperty(property, value);
+        } catch (SAXNotRecognizedException e) {
+            log(PROPERTY + NOT_RECOGNIZED + property, Project.MSG_VERBOSE);
+            return false;
+        } catch (SAXNotSupportedException e) {
+            log(PROPERTY + NOT_SUPPORTED + property, Project.MSG_VERBOSE);
+            return false;
+        }
+        return true;
+    }
+
+
+}

src/main/org/apache/tools/ant/types/defaults.properties

@@ -42,3 +42,4 @@ mavenrepository=org.apache.tools.ant.taskdefs.repository.MavenRepository
 scriptselector=org.apache.tools.ant.types.optional.ScriptSelector
 scriptcondition=org.apache.tools.ant.types.optional.ScriptCondition
 xor=org.apache.tools.ant.taskdefs.condition.Xor
+parsersupports=org.apache.tools.ant.taskdefs.condition.ParserSupports

src/testcases/org/apache/tools/ant/taskdefs/condition/ParserSupportsTest.java

@@ -0,0 +1,52 @@
+package org.apache.tools.ant.taskdefs.condition;
+
+import org.apache.tools.ant.BuildFileTest;
+
+/**
+ 
+ */
+public class ParserSupportsTest extends BuildFileTest {
+
+    public ParserSupportsTest(String name) {
+        super(name);
+    }
+
+    /**
+     * The JUnit setup method
+     */
+    public void setUp() {
+        configureProject("src/etc/testcases/taskdefs/conditions/parsersupports.xml");
+    }
+
+    public void testEmpty() throws Exception {
+        expectBuildExceptionContaining("testEmpty",
+                ParserSupports.ERROR_NO_ATTRIBUTES,
+                ParserSupports.ERROR_NO_ATTRIBUTES);
+    }
+
+    public void testBoth() throws Exception {
+        expectBuildExceptionContaining("testBoth",
+                ParserSupports.ERROR_BOTH_ATTRIBUTES,
+                ParserSupports.ERROR_BOTH_ATTRIBUTES);
+    }
+
+    public void testNamespaces() throws Exception {
+        executeTarget("testNamespaces");
+    }
+
+    public void testPropertyNoValue() throws Exception {
+        expectBuildExceptionContaining("testPropertyNoValue",
+                ParserSupports.ERROR_NO_VALUE,
+                ParserSupports.ERROR_NO_VALUE);
+    }
+
+    public void testUnknownProperty() throws Exception {
+        executeTarget("testUnknownProperty");
+    }
+    public void NotestPropertyInvalid() throws Exception {
+        executeTarget("testPropertyInvalid");
+    }
+    public void NotestXercesProperty() throws Exception {
+        executeTarget("testXercesProperty");
+    }
+}