Exemple #1
0
  /**
   * The constructor is protected, to ensure that instances can only be created using the
   * compileQuery() methods of StaticQueryContext
   *
   * @param exp an expression to be wrapped as an XQueryExpression
   * @param exec the executable
   * @param mainModule the static context of the main module
   * @param config the configuration
   * @throws XPathException if an error occurs
   */
  protected XQueryExpression(
      Expression exp, Executable exec, QueryModule mainModule, Configuration config)
      throws XPathException {
    stackFrameMap = config.makeSlotManager();
    executable = exec;
    exp.setContainer(this);
    try {
      ExpressionVisitor visitor = ExpressionVisitor.make(mainModule);
      visitor.setExecutable(exec);
      exp = visitor.simplify(exp);
      exp.checkForUpdatingSubexpressions();
      exp = visitor.typeCheck(exp, mainModule.getUserQueryContext().getRequiredContextItemType());
      //            ExpressionPresenter presenter = new ExpressionPresenter(config,
      //                    ExpressionPresenter.defaultDestination(config, new
      // FileOutputStream("c:/projects/montreal/before50.xml")));
      //            exp.explain(presenter);
      //            presenter.close();
      exp = exp.optimize(visitor, Type.ITEM_TYPE);
    } catch (XPathException err) {
      // err.printStackTrace();
      mainModule.reportFatalError(err);
      throw err;
    }
    ExpressionTool.allocateSlots(exp, 0, stackFrameMap);

    expression = exp;
    executable.setConfiguration(config);
    executable.setDefaultCollationName(mainModule.getDefaultCollationName());
    executable.setCollationTable(mainModule.getUserQueryContext().getAllCollations());
    staticContext = mainModule;
    isUpdating = exp.isUpdatingExpression();
  }
    /** Create and compile an XPath expression object. */
    public Object makeObject() throws Exception {
      if (logger.isDebugEnabled()) logger.debug("makeObject(" + xpathString + ")");

      // Create context
      final IndependentContext independentContext = new XPathCacheStaticContext(allowAllVariables);

      // Set the base URI if specified
      if (baseURI != null) independentContext.setBaseURI(baseURI);

      // Declare namespaces
      if (prefixToURIMap != null) {
        for (final String prefix : prefixToURIMap.keySet()) {
          independentContext.declareNamespace(prefix, prefixToURIMap.get(prefix));
        }
      }

      // Declare variables (we don't use the values here, just the names)
      final Map<String, Variable> variables = new HashMap<String, Variable>();
      if (variableNames != null) {
        for (final String name : variableNames) {
          final Variable variable = independentContext.declareVariable(name);
          variable.setUseStack(
              true); // "Indicate that values of variables are to be found on the stack, not in the
                     // Variable object itself"
          variables.put(name, variable);
        }
      }

      // Add function library
      if (functionLibrary != null) {
        // This is ok
        ((FunctionLibraryList) independentContext.getFunctionLibrary())
            .libraryList.add(0, functionLibrary);
      }

      // Create and compile the expression
      try {
        final Expression expression;
        if (isAvt) {
          final Expression tempExpression =
              AttributeValueTemplate.make(xpathString, -1, independentContext);
          // Running typeCheck() is mandatory otherwise things break! This is also done when using
          // evaluator.createExpression()
          expression = tempExpression.typeCheck(independentContext, Type.ITEM_TYPE);
        } else {
          // We used to use XPathEvaluator.createExpression(), but there is a bug in it related to
          // slots allocation, so we do the work ourselves instead.
          final Expression tempExpression =
              ExpressionTool.make(xpathString, independentContext, 0, Token.EOF, 1);
          expression = tempExpression.typeCheck(independentContext, Type.ITEM_TYPE);
        }

        // Allocate variable slots in all cases
        ExpressionTool.allocateSlots(
            expression,
            independentContext.getStackFrameMap().getNumberOfVariables(),
            independentContext.getStackFrameMap());

        {
          // Provide an Executable with the only purpose of allowing the evaluate() function find
          // the right
          // FunctionLibrary
          if (expression instanceof ComputedExpression) {
            final ComputedExpression computedExpression = (ComputedExpression) expression;
            computedExpression.setParentExpression(
                new Container() {

                  public Executable getExecutable() {
                    return new Executable() {
                      {
                        setFunctionLibrary(independentContext.getFunctionLibrary());
                        setLocationMap(new LocationMap());
                        setConfiguration(independentContext.getConfiguration());
                      }
                    };
                  }

                  public LocationProvider getLocationProvider() {
                    return computedExpression.getLocationProvider();
                  }

                  public int getHostLanguage() {
                    return Configuration.JAVA_APPLICATION;
                  }

                  public boolean replaceSubExpression(
                      Expression expression, Expression expression1) {
                    return computedExpression.replaceSubExpression(expression, expression1);
                  }

                  public int getColumnNumber() {
                    return (locationData != null) ? locationData.getCol() : -1;
                  }

                  public int getLineNumber() {
                    return (locationData != null) ? locationData.getLine() : -1;
                  }

                  public String getPublicId() {
                    return (locationData != null) ? locationData.getPublicID() : null;
                  }

                  public String getSystemId() {
                    return (locationData != null) ? locationData.getSystemID() : null;
                  }
                });
          }
        }

        // TODO: For now only play with XForms expressions. But should decide probably based on
        // flag?
        if (false && functionLibrary == XFormsContainingDocument.getFunctionLibrary()) {
          final List<String> instanceIds = analyzeExpression(expression, xpathString);
          if (instanceIds == null)
            logger.info("  XXX EXPRESSION DEPENDS ON MORE THAN INSTANCES: " + xpathString);
          else {
            logger.info("  XXX EXPRESSION DEPENDS ON INSTANCES: " + xpathString);
            for (String instanceId : instanceIds) {
              logger.info("    instance: " + instanceId);
            }
          }
        }

        return new PooledXPathExpression(expression, pool, independentContext, variables);
      } catch (Throwable t) {
        throw new OXFException(t);
      }
    }