protected TagScript createTag()

in core/src/main/java/org/apache/commons/jelly/parser/XMLParser.java [464:539]
62 lines of code
15 McCabe index (conditional complexity)

    protected TagScript createTag(
        String namespaceURI,
        String localName,
        Attributes list)
        throws SAXException {
        try {
            // use the URI to load a taglib
            TagLibrary taglib = context.getTagLibrary(namespaceURI);
            if (taglib == null) {
                if (namespaceURI != null && namespaceURI.startsWith("jelly:")) {
                    String uri = namespaceURI.substring(6);
                    // try to find the class on the classpath
                    try {
                        Class taglibClass = getClassLoader().loadClass(uri);
                        taglib = (TagLibrary) taglibClass.getConstructor().newInstance();
                        context.registerTagLibrary(namespaceURI, taglib);
                    }
                    catch (ClassNotFoundException e) {
                        throw createSAXException("Could not load class: " + uri + " so taglib instantiation failed", e);
                    }
                    catch (IllegalAccessException e) {
                        throw createSAXException("Constructor for class is not accessible: " + uri + " so taglib instantiation failed", e);
                    }
                    catch (InstantiationException e) {
                        throw createSAXException("Class could not be instantiated: " + uri + " so taglib instantiation failed", e);
                    }
                    catch (ClassCastException e) {
                        throw createSAXException("Class is not a TagLibrary: " + uri + " so taglib instantiation failed", e);
                    }
                }
            }
            if (taglib != null) {
                TagScript script = taglib.createTagScript(localName, list);
                if ( script != null ) {
                    configureTagScript(taglib, script);

                    // clone the attributes to keep them around after this parse
                    script.setSaxAttributes(new AttributesImpl(list));

                    // now iterate through through the expressions
                    int size = list.getLength();
                    for (int i = 0; i < size; i++) {
                        String attributeName = list.getLocalName(i);
                        // Fix for JELLY-184 where the xmlns attributes have a blank name and cause
                        //	an exception later on
                        if (attributeName.length() == 0)
                        	continue;
                        String attributeValue = list.getValue(i);
                        Expression expression =
                            createExpression(script,
                                attributeName,
                                attributeValue);
//                        Expression expression =
//                            taglib.createExpression(
//                                getExpressionFactory(),
//                                script,
//                                attributeName,
//                                attributeValue);
                        if (expression == null) {
                            expression = createConstantExpression(localName, attributeName, attributeValue);
                        }
                        script.addAttribute(attributeName, expression);
                    }
                } else if (!taglib.isAllowUnknownTags())
                    throw new JellyException("Unrecognized tag called " + localName + " in TagLibrary " + namespaceURI);
                return script;
            }
            return null;
        }
        catch (Exception e) {
            log.warn(
                "Could not create taglib or URI: " + namespaceURI + " tag name: " + localName,
                e);
            throw createSAXException(e);
        }
    }