How to use

AttributeExpressionImpl

in

org.geotools.filter

public PropertyName property(String name) {
  return new AttributeExpressionImpl(name);
}

  public void testSetupAndExtraction() throws Exception {
    // this should move out to a more configurable system run from scripts
    // but we can start with a set of hard coded tests
    SimpleFeature[] f = sampleFeatures();

    AttributeExpressionImpl e1 = new AttributeExpressionImpl(schema, "value");
    AttributeExpressionImpl e2 = new AttributeExpressionImpl(schema, "name");

    assertEquals(12d, ((Integer) e1.evaluate(f[0])).doubleValue(), 0);
    assertEquals(3d, ((Integer) e1.evaluate(f[1])).doubleValue(), 0);
    assertEquals(15d, ((Integer) e1.evaluate(f[2])).doubleValue(), 0);
    assertEquals("first", (String) e2.evaluate(f[0]));
    assertEquals("second", (String) e2.evaluate(f[1]));
  }
}

+ isEqual
+ "; in:"
+ expAttr.getPropertyName()
+ "; out:"
+ this.attPath);

  public PropertyName property(String name) {
    AttributeExpressionImpl att = new AttributeExpressionImpl(name);
    att.setLenient(false);
    return att;
  }
}

    new AttributeExpressionImpl(
        "eg:simpleAttribute",
        new Hints(FeaturePropertyAccessorFactory.NAMESPACE_CONTEXT, NAMESPACES));
assertEquals(simpleAttribute, ex.evaluate(feature));
    new AttributeExpressionImpl(
        "eg:complexAttribute",
        new Hints(FeaturePropertyAccessorFactory.NAMESPACE_CONTEXT, NAMESPACES));
assertEquals(complexAttribute, ex.evaluate(feature));
    new AttributeExpressionImpl(
        "eg:complexAttribute/eg:rootAttribute",
        new Hints(FeaturePropertyAccessorFactory.NAMESPACE_CONTEXT, NAMESPACES));
Object o = ex.evaluate(feature);
assertTrue(o instanceof List);
assertEquals(3, ((List) o).size());
    new AttributeExpressionImpl(
        "eg:complexAttribute/eg:rootAttribute/eg:singleLeafAttribute",
        new Hints(FeaturePropertyAccessorFactory.NAMESPACE_CONTEXT, NAMESPACES));
o = ex.evaluate(feature);
assertTrue(o instanceof List);
assertEquals(3, ((List) o).size());
    new AttributeExpressionImpl(
        "eg:complexAttribute/eg:rootAttribute[1]",
        new Hints(FeaturePropertyAccessorFactory.NAMESPACE_CONTEXT, NAMESPACES));

/**
 * Gets the value of this property from the passed object.
 *
 * @param obj Object from which we need to extract a property value.
 */
public Object evaluate(Object obj) {
  return evaluate(obj, null);
}

AttributeExpressionImpl expAttr = (AttributeExpressionImpl) obj;
boolean isEqual = (expAttr.getType() == this.expressionType);
if(LOGGER.isLoggable(Level.FINEST))
  LOGGER.finest("expression type match:" + isEqual + "; in:"
  + expAttr.getType() + "; out:" + this.expressionType);
isEqual = (expAttr.attPath != null)
  ? (isEqual && expAttr.attPath.equals(this.attPath))
if(LOGGER.isLoggable(Level.FINEST))
  LOGGER.finest("attribute match:" + isEqual + "; in:"
  + expAttr.getAttributePath() + "; out:" + this.attPath);
isEqual = (expAttr.schema != null)
  ? (isEqual && expAttr.schema.equals(this.schema))

/**
 * Constructor with schema and path to the attribute.
 *
 * @param schema The initial (required) sub filter.
 * @param attPath the xpath to the attribute.
 *
 * @throws IllegalFilterException If the attribute path is not in the
 *         schema.
 */
protected AttributeExpressionImpl(SimpleFeatureType schema, String attPath)
  throws IllegalFilterException {
  this.schema = schema;
  this.expressionType = ATTRIBUTE;
  setAttributePath(attPath);
}

AttributeExpressionImpl ex = new AttributeExpressionImpl("eg:simpleAttribute", new Hints(
    FeaturePropertyAccessorFactory.NAMESPACE_CONTEXT, NAMESPACES));
assertEquals(simpleAttribute, ex.evaluate(feature));
ex = new AttributeExpressionImpl("eg:complexAttribute", new Hints(
    FeaturePropertyAccessorFactory.NAMESPACE_CONTEXT, NAMESPACES));
assertEquals(complexAttribute, ex.evaluate(feature));
ex = new AttributeExpressionImpl("eg:complexAttribute/eg:rootAttribute", new Hints(
    FeaturePropertyAccessorFactory.NAMESPACE_CONTEXT, NAMESPACES));
Object o = ex.evaluate(feature);
assertTrue( o instanceof List );        
assertEquals(3,  ((List) o).size());
ex = new AttributeExpressionImpl("eg:complexAttribute/eg:rootAttribute/eg:singleLeafAttribute", new Hints(
    FeaturePropertyAccessorFactory.NAMESPACE_CONTEXT, NAMESPACES));
o = ex.evaluate(feature);
assertTrue( o instanceof List );     
assertEquals(3,  ((List) o).size());
ex = new AttributeExpressionImpl("eg:complexAttribute/eg:rootAttribute[1]", new Hints(
    FeaturePropertyAccessorFactory.NAMESPACE_CONTEXT, NAMESPACES));
 assertEquals(rootOne, ex.evaluate(feature));
ex = new AttributeExpressionImpl("eg:complexAttribute/eg:rootAttribute[2]", new Hints(
    FeaturePropertyAccessorFactory.NAMESPACE_CONTEXT, NAMESPACES));
assertEquals(rootTwo, ex.evaluate(feature));

public PropertyName property(String name) {
  AttributeExpressionImpl att = new AttributeExpressionImpl(name);
  att.setLenient(false);
  return att;
}

/**
 * Gets the value of this attribute from the passed feature.
 *
 * @param feature Feature from which to extract attribute value.
 */
public Object evaluate(SimpleFeature feature) {
  //NC - is exact copy of code anyway, don't need to keep changing both
  //this method can probably be removed all together
  return evaluate((Object) feature, null); 
  }

AttributeExpressionImpl expAttr = (AttributeExpressionImpl) obj;
boolean isEqual = (expAttr.getType() == this.expressionType);
if(LOGGER.isLoggable(Level.FINEST))
  LOGGER.finest("expression type match:" + isEqual + "; in:"
  + expAttr.getType() + "; out:" + this.expressionType);
isEqual = (expAttr.attPath != null)
  ? (isEqual && expAttr.attPath.equals(this.attPath))
if(LOGGER.isLoggable(Level.FINEST))
  LOGGER.finest("attribute match:" + isEqual + "; in:"
  + expAttr.getAttributePath() + "; out:" + this.attPath);
isEqual = (expAttr.schema != null)
  ? (isEqual && expAttr.schema.equals(this.schema))

/**
 * Constructor with schema and path to the attribute.
 *
 * @param schema The initial (required) sub filter.
 * @param attPath the xpath to the attribute.
 *
 * @throws IllegalFilterException If the attribute path is not in the
 *         schema.
 */
protected AttributeExpressionImpl(FeatureType schema, String attPath)
  throws IllegalFilterException {
  this.schema = schema;
  this.expressionType = ATTRIBUTE;
  setAttributePath(attPath);
}

public PropertyName property(Name name) {
  return new AttributeExpressionImpl(name);
}

  public void testSetupAndExtraction() throws Exception {
    // this should move out to a more configurable system run from scripts
    // but we can start with a set of hard coded tests
    SimpleFeature[] f = sampleFeatures();

    AttributeExpressionImpl e1 = new AttributeExpressionImpl(schema, "value");
    AttributeExpressionImpl e2 = new AttributeExpressionImpl(schema, "name");

    assertEquals(12d, ((Integer) e1.evaluate(f[0])).doubleValue(), 0);
    assertEquals(3d, ((Integer) e1.evaluate(f[1])).doubleValue(), 0);
    assertEquals(15d, ((Integer) e1.evaluate(f[2])).doubleValue(), 0);
    assertEquals("first", (String) e2.evaluate(f[0]));
    assertEquals("second", (String) e2.evaluate(f[1]));
  }
}

    new AttributeExpressionImpl(
        "eg:simpleAttribute",
        new Hints(FeaturePropertyAccessorFactory.NAMESPACE_CONTEXT, NAMESPACES));
assertEquals(simpleAttribute, ex.evaluate(feature));
    new AttributeExpressionImpl(
        "eg:complexAttribute",
        new Hints(FeaturePropertyAccessorFactory.NAMESPACE_CONTEXT, NAMESPACES));
assertEquals(complexAttribute, ex.evaluate(feature));
    new AttributeExpressionImpl(
        "eg:complexAttribute/eg:rootAttribute",
        new Hints(FeaturePropertyAccessorFactory.NAMESPACE_CONTEXT, NAMESPACES));
Object o = ex.evaluate(feature);
assertTrue(o instanceof List);
assertEquals(3, ((List) o).size());
    new AttributeExpressionImpl(
        "eg:complexAttribute/eg:rootAttribute/eg:singleLeafAttribute",
        new Hints(FeaturePropertyAccessorFactory.NAMESPACE_CONTEXT, NAMESPACES));
o = ex.evaluate(feature);
assertTrue(o instanceof List);
assertEquals(3, ((List) o).size());
    new AttributeExpressionImpl(
        "eg:complexAttribute/eg:rootAttribute[1]",
        new Hints(FeaturePropertyAccessorFactory.NAMESPACE_CONTEXT, NAMESPACES));

protected Object getValues(
    boolean isMultiValued, Expression expression, Object sourceFeatureInput) {
  if (isMultiValued
      && sourceFeatureInput instanceof FeatureImpl
      && expression instanceof AttributeExpressionImpl) {
    // RA: Feature Chaining
    // complex features can have multiple nodes of the same attribute.. and if they are used
    // as input to an app-schema data access to be nested inside another feature type of a
    // different XML type, it has to be mapped like this:
    // <AttributeMapping>
    // <targetAttribute>
    // gsml:composition
    // </targetAttribute>
    // <sourceExpression>
    // <inputAttribute>mo:composition</inputAttribute>
    // <linkElement>gsml:CompositionPart</linkElement>
    // <linkField>gml:name</linkField>
    // </sourceExpression>
    // <isMultiple>true</isMultiple>
    // </AttributeMapping>
    // As there can be multiple nodes of mo:composition in this case, we need to retrieve
    // all of them
    AttributeExpressionImpl attribExpression = ((AttributeExpressionImpl) expression);
    String xpath = attribExpression.getPropertyName();
    ComplexAttribute sourceFeature = (ComplexAttribute) sourceFeatureInput;
    StepList xpathSteps = XPath.steps(sourceFeature.getDescriptor(), xpath, namespaces);
    return getProperties(sourceFeature, xpathSteps);
  }
  return expression.evaluate(sourceFeatureInput);
}

/**
 * Gets the value of this property from the passed object.
 *
 * @param obj Object from which we need to extract a property value.
 */
public Object evaluate(Object obj) {
  return evaluate(obj, null);
}

public PropertyName property(String name, NamespaceSupport namespaceContext) {
  if (namespaceContext == null) {
    return property(name);
  }
  return new AttributeExpressionImpl(name, namespaceContext);
}

public void testTypeMissmatch() throws Exception {
  SimpleFeature[] f = sampleFeatures();
  // the following are intentionaly backwards
  AttributeExpressionImpl e1 = new AttributeExpressionImpl(schema, "value");
  AttributeExpressionImpl e2 = new AttributeExpressionImpl(schema, "name");
  boolean pass = false;
  Object value = null;
  value = e1.evaluate(f[0]);
  if (value instanceof Integer) {
    pass = true;
  }
  assertTrue("String expresion returned an Integer", pass);
  pass = false;
  value = e2.evaluate(f[0]);
  if (value instanceof String) {
    pass = true;
  }
  assertTrue("Integer expresion returned a String", pass);
}