Examples with Fragment org.thymeleaf.standard.expression.Fragment used on opensource projects

Example 1 with Fragment

use of org.thymeleaf.standard.expression.Fragment in project thymeleaf by thymeleaf.

the class AbstractStandardFragmentInsertionTagProcessor method computeFragment.

/*
     * This can return a Fragment, NoOpToken (if nothing should be done) or null
     */
private static Object computeFragment(final ITemplateContext context, final String input) {
    final IStandardExpressionParser expressionParser = StandardExpressions.getExpressionParser(context.getConfiguration());
    final String trimmedInput = input.trim();
    if (shouldBeWrappedAsFragmentExpression(trimmedInput)) {
        // We do not know for sure that this is a complete standard expression, so we will consider it the
        // content of a FragmentExpression for legacy compatibility reasons.
        // We will only reach this point if the expression does not contain any Fragment Expressions expressed
        // as ~{...} (excluding parameters), nor the "::" fragment selector separator.
        // NOTE we are using the generic parseExpression() and not directly calling a parse method in the
        // FragmentExpression class because we want to take advantage of the expression cache.
        final FragmentExpression fragmentExpression = (FragmentExpression) expressionParser.parseExpression(context, "~{" + trimmedInput + "}");
        final FragmentExpression.ExecutedFragmentExpression executedFragmentExpression = FragmentExpression.createExecutedFragmentExpression(context, fragmentExpression);
        if (executedFragmentExpression.getFragmentSelectorExpressionResult() == null && executedFragmentExpression.getFragmentParameters() == null) {
            // We might be in the scenario that what we thought was a template name in fact was instead an expression
            // returning a Fragment itself, so we should simply return it
            final Object templateNameExpressionResult = executedFragmentExpression.getTemplateNameExpressionResult();
            if (templateNameExpressionResult != null) {
                if (templateNameExpressionResult instanceof Fragment) {
                    return templateNameExpressionResult;
                }
                if (templateNameExpressionResult == NoOpToken.VALUE) {
                    return NoOpToken.VALUE;
                }
            }
        }
        // have to execute a (potentially costly) resource.exists() call on the resolved resource.
        return FragmentExpression.resolveExecutedFragmentExpression(context, executedFragmentExpression, true);
    }
    // If we reached this point, we know for sure this is a complete fragment expression, so we just parse it
    // as such and execute it
    final IStandardExpression fragmentExpression = expressionParser.parseExpression(context, trimmedInput);
    final Object fragmentExpressionResult;
    if (fragmentExpression != null && fragmentExpression instanceof FragmentExpression) {
        // This is not a complex expression but merely a FragmentExpression, so we can apply a shortcut
        // so that we don't require a "null" result for this expression if the template does not exist. That will
        // save a call to resource.exists() which might be costly.
        final FragmentExpression.ExecutedFragmentExpression executedFragmentExpression = FragmentExpression.createExecutedFragmentExpression(context, (FragmentExpression) fragmentExpression);
        fragmentExpressionResult = FragmentExpression.resolveExecutedFragmentExpression(context, executedFragmentExpression, true);
    } else {
        fragmentExpressionResult = fragmentExpression.execute(context);
    }
    if (fragmentExpressionResult == null || fragmentExpressionResult == NoOpToken.VALUE) {
        return fragmentExpressionResult;
    }
    if (!(fragmentExpressionResult instanceof Fragment)) {
        throw new TemplateProcessingException("Invalid fragment specification: \"" + input + "\": " + "expression does not return a Fragment object");
    }
    return fragmentExpressionResult;
}

Example 2 with Fragment

use of org.thymeleaf.standard.expression.Fragment in project thymeleaf by thymeleaf.

the class AbstractStandardFragmentInsertionTagProcessor method doProcess.

@Override
protected void doProcess(final ITemplateContext context, final IProcessableElementTag tag, final AttributeName attributeName, final String attributeValue, final IElementTagStructureHandler structureHandler) {
    if (StringUtils.isEmptyOrWhitespace(attributeValue)) {
        throw new TemplateProcessingException("Fragment specifications cannot be empty");
    }
    final IEngineConfiguration configuration = context.getConfiguration();
    /*
         * PARSE AND PROCESS THE FRAGMENT
         */
    final Object fragmentObj = computeFragment(context, attributeValue);
    if (fragmentObj == null) {
        throw new TemplateInputException("Error resolving fragment: \"" + attributeValue + "\": " + "template or fragment could not be resolved");
    } else if (fragmentObj == NoOpToken.VALUE) {
        // If the Fragment result is NO-OP, we will just do nothing (apart from deleting the th:* attribute)
        return;
    } else if (fragmentObj == Fragment.EMPTY_FRAGMENT) {
        // tag (th:insert) or remove it completely, tag included (th:replace)
        if (this.replaceHost) {
            structureHandler.removeElement();
        } else {
            structureHandler.removeBody();
        }
        return;
    }
    final Fragment fragment = (Fragment) fragmentObj;
    final TemplateModel fragmentModel = fragment.getTemplateModel();
    Map<String, Object> fragmentParameters = fragment.getParameters();
    /*
         * ONCE WE HAVE THE FRAGMENT MODEL (its events, in fact), CHECK THE FRAGMENT SIGNATURE
         * Fragment signature is important because it might affect the way we apply the parameters to the fragment.
         *
         * Note this works whatever the template mode of the inserted fragment, given we are looking for an
         * element containing a "th:fragment/data-th-fragment" in a generic, non-template-dependent way.
         */
    // We will check types first instead of events in order to (many times) avoid creating an immutably-wrapped
    // event object when calling "model.get(pos)"
    boolean signatureApplied = false;
    final ITemplateEvent firstEvent = (fragmentModel.size() > 2 ? fragmentModel.get(1) : null);
    if (firstEvent != null && IProcessableElementTag.class.isAssignableFrom(firstEvent.getClass())) {
        final String dialectPrefix = attributeName.getPrefix();
        final IProcessableElementTag fragmentHolderEvent = (IProcessableElementTag) firstEvent;
        if (fragmentHolderEvent.hasAttribute(dialectPrefix, FRAGMENT_ATTR_NAME)) {
            // The selected fragment actually has a "th:fragment" attribute, so we should process its signature
            final String fragmentSignatureSpec = EscapedAttributeUtils.unescapeAttribute(fragmentModel.getTemplateMode(), fragmentHolderEvent.getAttributeValue(dialectPrefix, FRAGMENT_ATTR_NAME));
            if (!StringUtils.isEmptyOrWhitespace(fragmentSignatureSpec)) {
                final FragmentSignature fragmentSignature = FragmentSignatureUtils.parseFragmentSignature(configuration, fragmentSignatureSpec);
                if (fragmentSignature != null) {
                    // Reshape the fragment parameters into the ones that we will actually use, according to the signature
                    fragmentParameters = FragmentSignatureUtils.processParameters(fragmentSignature, fragmentParameters, fragment.hasSyntheticParameters());
                    signatureApplied = true;
                }
            }
        }
    }
    // not being applied, maybe not realising there was no signature assignation involved.
    if (!signatureApplied && fragment.hasSyntheticParameters()) {
        throw new TemplateProcessingException("Fragment '" + attributeValue + "' specifies synthetic (unnamed) parameters, but the resolved fragment " + "does not match a fragment signature (th:fragment,data-th-fragment) which could apply names to " + "the specified parameters.");
    }
    /*
         * CHECK WHETHER THIS IS A CROSS-TEMPLATE-MODE INSERTION. Only TemplateModels for the same template mode
         * can be safely inserted into the template being executed and processed just like any other sequences of
         * events. If the inserted template has a different template mode, we will need to process it aside and
         * obtain a String result for it, then insert such String as mere text.
         *
         * Note inserting large templates with a different template mode could therefore have a negative effect
         * on performance and memory usage, as their result needs to be completely stored in memory at some point
         * before being handled to the following phases of template processing. It is therefore recommended that
         * cross-template-mode fragment insertion is done only for small fragments, in which case it will work
         * almost the same as inlining (with the exception that the content to be inlined will be retrieved from
         * somewhere else by means of template resolution).
         */
    if (context.getTemplateMode() != fragmentModel.getTemplateMode()) {
        // Check if this is a th:include. If so, just don't allow
        if (this.insertOnlyContents) {
            throw new TemplateProcessingException("Template being processed uses template mode " + context.getTemplateMode() + ", " + "inserted fragment \"" + attributeValue + "\" uses template mode " + fragmentModel.getTemplateMode() + ". Cross-template-mode fragment insertion is not " + "allowed using the " + attributeName + " attribute, which is no longer recommended for use as " + "of Thymeleaf 3.0. Use {th:insert,data-th-insert} or {th:replace,data-th-replace} " + "instead, which do not remove the container element from the fragment being inserted.");
        }
        // doing it through the structure handler (we are going to perform a nested template processing operation)
        if (fragmentParameters != null && fragmentParameters.size() > 0) {
            if (!(context instanceof IEngineContext)) {
                throw new TemplateProcessingException("Parameterized fragment insertion is not supported because local variable support is DISABLED. This is due to " + "the use of an implementation of the " + ITemplateContext.class.getName() + " interface that does " + "not provide local-variable support. In order to have local-variable support, the variables map " + "implementation should also implement the " + IEngineContext.class.getName() + " interface");
            }
            // NOTE this IEngineContext interface is internal and should not be used in users' code
            ((IEngineContext) context).setVariables(fragmentParameters);
        }
        // Once parameters are in order, just process the template in a nested template engine execution
        final Writer stringWriter = new FastStringWriter(200);
        configuration.getTemplateManager().process(fragmentModel, context, stringWriter);
        // We will insert the result as NON-PROCESSABLE text (it's already been processed!)
        if (this.replaceHost) {
            structureHandler.replaceWith(stringWriter.toString(), false);
        } else {
            structureHandler.setBody(stringWriter.toString(), false);
        }
        return;
    }
    /*
         * APPLY THE FRAGMENT'S TEMPLATE RESOLUTION so that all code inside the fragment is executed with its own
         * template resolution info (working as if it were a local variable)
         */
    final TemplateData fragmentTemplateData = fragmentModel.getTemplateData();
    structureHandler.setTemplateData(fragmentTemplateData);
    /*
         * APPLY THE FRAGMENT PARAMETERS AS LOCAL VARIABLES, perhaps after reshaping it according to the fragment signature
         */
    if (fragmentParameters != null && fragmentParameters.size() > 0) {
        for (final Map.Entry<String, Object> fragmentParameterEntry : fragmentParameters.entrySet()) {
            structureHandler.setLocalVariable(fragmentParameterEntry.getKey(), fragmentParameterEntry.getValue());
        }
    }
    /*
         * IF WE ARE ASKING ONLY FOR CONTENTS (th:include), THEN REMOVE THE CONTAINER BLOCK
         */
    if (this.insertOnlyContents && fragmentTemplateData.hasTemplateSelectors()) {
        /*
             * In the case of th:include, things get a bit complicated because we need to remove the "element envelopes"
             * that contain what we really want to include (these envelopes' contents). So we will need to traverse
             * the entire returned model detecting those envelopes (open+close tags at model level == 0) and remove
             * them, along with anything else that is also at that level 0.
             */
        final IModel model = fragmentModel.cloneModel();
        int modelLevel = 0;
        int n = model.size();
        while (n-- != 0) {
            // We traverse backwards so that we can modify at the same time
            final ITemplateEvent event = model.get(n);
            if (event instanceof ICloseElementTag) {
                if (((ICloseElementTag) event).isUnmatched()) {
                    // This is an unmatched close tag (no corresponding open), therefore should not affect our count
                    continue;
                }
                if (modelLevel <= 0) {
                    model.remove(n);
                }
                modelLevel++;
                continue;
            }
            if (event instanceof IOpenElementTag) {
                modelLevel--;
                if (modelLevel <= 0) {
                    model.remove(n);
                }
                continue;
            }
            if (modelLevel <= 0) {
                model.remove(n);
            }
        }
        if (this.replaceHost) {
            structureHandler.replaceWith(model, true);
        } else {
            structureHandler.setBody(model, true);
        }
        return;
    }
    if (this.replaceHost) {
        structureHandler.replaceWith(fragmentModel, true);
    } else {
        structureHandler.setBody(fragmentModel, true);
    }
}

Example 3 with Fragment

use of org.thymeleaf.standard.expression.Fragment in project thymeleaf by thymeleaf.

the class StandardUtextTagProcessor method doProcess.

@Override
protected void doProcess(final ITemplateContext context, final IProcessableElementTag tag, final AttributeName attributeName, final String attributeValue, final IElementTagStructureHandler structureHandler) {
    final IEngineConfiguration configuration = context.getConfiguration();
    final IStandardExpressionParser expressionParser = StandardExpressions.getExpressionParser(configuration);
    final IStandardExpression expression = expressionParser.parseExpression(context, attributeValue);
    final Object expressionResult;
    if (expression != null && expression instanceof FragmentExpression) {
        // This is merely a FragmentExpression (not complex, not combined with anything), so we can apply a shortcut
        // so that we don't require a "null" result for this expression if the template does not exist. That will
        // save a call to resource.exists() which might be costly.
        final FragmentExpression.ExecutedFragmentExpression executedFragmentExpression = FragmentExpression.createExecutedFragmentExpression(context, (FragmentExpression) expression);
        expressionResult = FragmentExpression.resolveExecutedFragmentExpression(context, executedFragmentExpression, true);
    } else {
        expressionResult = expression.execute(context, StandardExpressionExecutionContext.RESTRICTED);
    }
    // If result is no-op, there's nothing to execute
    if (expressionResult == NoOpToken.VALUE) {
        return;
    }
    /*
         * First of all we should check whether the expression result is a Fragment so that, in such case, we can
         * avoid creating a String in memory for it and just append its model.
         */
    if (expressionResult != null && expressionResult instanceof Fragment) {
        if (expressionResult == Fragment.EMPTY_FRAGMENT) {
            structureHandler.removeBody();
            return;
        }
        structureHandler.setBody(((Fragment) expressionResult).getTemplateModel(), false);
        return;
    }
    final String unescapedTextStr = (expressionResult == null ? "" : expressionResult.toString());
    /*
         * We will check if there are configured post processors or not. The reason we do this is because output
         * inserted as a result of a th:utext attribute, even if it might be markup, will never be considered as
         * 'processable', i.e. no other processors/inliner will ever be able to act on it. The main reason for this
         * is to protect against code injection.
         *
         * So the only other agents that would be able to modify these th:utext results are POST-PROCESSORS. And
         * they will indeed need markup to have been parsed in order to separate text from structures, so that's why
         * we check if there actually are any post-processors and, if not (most common case), simply output the
         * expression result as if it were a mere (unescaped) text node.
         */
    final Set<IPostProcessor> postProcessors = configuration.getPostProcessors(getTemplateMode());
    if (postProcessors.isEmpty()) {
        structureHandler.setBody(unescapedTextStr, false);
        return;
    }
    /*
         * We have post-processors, so from here one we will have to decide whether we need to parse the unescaped
         * text or not...
         */
    if (!mightContainStructures(unescapedTextStr)) {
        // If this text contains no markup structures, there would be no need to parse it or treat it as markup!
        structureHandler.setBody(unescapedTextStr, false);
        return;
    }
    /*
         * We have post-processors AND this text might contain structures, so there is no alternative but parsing
         */
    final TemplateModel parsedFragment = configuration.getTemplateManager().parseString(context.getTemplateData(), unescapedTextStr, // we won't apply offset here because the inserted text does not really come from the template itself
    0, // we won't apply offset here because the inserted text does not really come from the template itself
    0, // No template mode forcing required
    null, // useCache == false because we could potentially pollute the cache with too many entries (th:utext is too variable!)
    false);
    // Setting 'processable' to false avoiding text inliners processing already generated text,
    // which in turn avoids code injection.
    structureHandler.setBody(parsedFragment, false);
}