refactor: head and footer tag injection to skip error pages

application/src/main/java/run/halo/app/theme/dialect/GlobalHeadInjectionProcessor.java

@@ -42,6 +42,9 @@ public GlobalHeadInjectionProcessor(final String dialectPrefix) {
     @Override
     protected void doProcess(ITemplateContext context, IModel model,
         IElementModelStructureHandler structureHandler) {
+        if (context.containsVariable(InjectionExcluderProcessor.EXCLUDE_INJECTION_VARIABLE)) {
+            return;
+        }
 
         // note that this is important!!
         Object processedAlready = context.getVariable(PROCESS_FLAG);

application/src/main/java/run/halo/app/theme/dialect/HaloProcessorDialect.java

@@ -41,6 +41,7 @@ public Set<IProcessor> getProcessors(String dialectPrefix) {
         processors.add(new EvaluationContextEnhancer());
         processors.add(new CommentElementTagProcessor(dialectPrefix));
         processors.add(new CommentEnabledVariableProcessor());
+        processors.add(new InjectionExcluderProcessor());
         return processors;
     }
 

application/src/main/java/run/halo/app/theme/dialect/InjectionExcluderProcessor.java

@@ -0,0 +1,92 @@
+package run.halo.app.theme.dialect;
+
+import java.util.Set;
+import java.util.regex.Pattern;
+import org.springframework.util.Assert;
+import org.thymeleaf.context.ITemplateContext;
+import org.thymeleaf.model.ITemplateEnd;
+import org.thymeleaf.model.ITemplateStart;
+import org.thymeleaf.processor.templateboundaries.AbstractTemplateBoundariesProcessor;
+import org.thymeleaf.processor.templateboundaries.ITemplateBoundariesProcessor;
+import org.thymeleaf.processor.templateboundaries.ITemplateBoundariesStructureHandler;
+import org.thymeleaf.standard.StandardDialect;
+import org.thymeleaf.templatemode.TemplateMode;
+
+/**
+ * <p>Determine whether the current template being rendered needs to exclude the processor of
+ * code injection. If it needs to be excluded, set a local variable.</p>
+ * <p>Why do you need to set a local variable here instead of directly judging in the processor?</p>
+ * <p>Because the processor will process the fragment, and if you need to exclude the <code>login
+ * .html</code> template and the login.html is only a fragment, then the exclusion logic will
+ * fail, so here use {@link ITemplateBoundariesProcessor} events are only fired for the
+ * first-level template to solve this problem.</p>
+ *
+ * @author guqing
+ * @since 2.20.0
+ */
+public class InjectionExcluderProcessor extends AbstractTemplateBoundariesProcessor {
+
+    public static final String EXCLUDE_INJECTION_VARIABLE =
+        InjectionExcluderProcessor.class.getName() + ".EXCLUDE_INJECTION";
+
+    private final PageInjectionExcluder injectionExcluder = new PageInjectionExcluder();
+
+    public InjectionExcluderProcessor() {
+        super(TemplateMode.HTML, StandardDialect.PROCESSOR_PRECEDENCE);
+    }
+
+    @Override
+    public void doProcessTemplateStart(ITemplateContext context, ITemplateStart templateStart,
+        ITemplateBoundariesStructureHandler structureHandler) {
+        if (isExcluded(context)) {
+            structureHandler.setLocalVariable(EXCLUDE_INJECTION_VARIABLE, true);
+        }
+    }
+
+    @Override
+    public void doProcessTemplateEnd(ITemplateContext context, ITemplateEnd templateEnd,
+        ITemplateBoundariesStructureHandler structureHandler) {
+        structureHandler.removeLocalVariable(EXCLUDE_INJECTION_VARIABLE);
+    }
+
+    /**
+     * Check if the template will be rendered is excluded injection.
+     *
+     * @param context template context
+     * @return true if the template is excluded, otherwise false
+     */
+    boolean isExcluded(ITemplateContext context) {
+        return injectionExcluder.isExcluded(context.getTemplateData().getTemplate());
+    }
+
+    static class PageInjectionExcluder {
+
+        private final Set<String> exactMatches = Set.of(
+            "login",
+            "signup",
+            "logout"
+        );
+
+        private final Set<Pattern> regexPatterns = Set.of(
+            Pattern.compile("error/.*"),
+            Pattern.compile("challenges/.*"),
+            Pattern.compile("password-reset/.*"),
+            Pattern.compile("login_.*")
+        );
+
+        public boolean isExcluded(String templateName) {
+            Assert.notNull(templateName, "Template name must not be null");
+            if (exactMatches.contains(templateName)) {
+                return true;
+            }
+
+            for (Pattern pattern : regexPatterns) {
+                if (pattern.matcher(templateName).matches()) {
+                    return true;
+                }
+            }
+
+            return false;
+        }
+    }
+}

application/src/main/java/run/halo/app/theme/dialect/TemplateFooterElementTagProcessor.java

@@ -48,6 +48,10 @@ public TemplateFooterElementTagProcessor(final String dialectPrefix) {
     protected void doProcess(ITemplateContext context, IProcessableElementTag tag,
         IElementTagStructureHandler structureHandler) {
 
+        if (context.containsVariable(InjectionExcluderProcessor.EXCLUDE_INJECTION_VARIABLE)) {
+            return;
+        }
+
         IModel modelToInsert = context.getModelFactory().createModel();
         /*
          * Obtain the Spring application context.

application/src/test/java/run/halo/app/theme/dialect/InjectionExcluderProcessorTest.java

@@ -0,0 +1,63 @@
+package run.halo.app.theme.dialect;
+
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Tests for {@link InjectionExcluderProcessor}.
+ *
+ * @author guqing
+ * @since 2.20.0
+ */
+class InjectionExcluderProcessorTest {
+
+    @Nested
+    class PageInjectionExcluderTest {
+        final InjectionExcluderProcessor.PageInjectionExcluder pageInjectionExcluder =
+            new InjectionExcluderProcessor.PageInjectionExcluder();
+
+        @Test
+        void excludeTest() {
+            var cases = new String[] {
+                "login",
+                "signup",
+                "logout",
+                "password-reset/email/reset",
+                "error/404",
+                "error/500",
+                "challenges/totp",
+                "login_local"
+            };
+
+            for (String templateName : cases) {
+                assertThat(pageInjectionExcluder.isExcluded(templateName)).isTrue();
+            }
+        }
+
+        @Test
+        void shouldNotExcludeTest() {
+            var cases = new String[] {
+                "index",
+                "post",
+                "page",
+                "category",
+                "tag",
+                "archive",
+                "search",
+                "feed",
+                "sitemap",
+                "robots",
+                "custom",
+                "error",
+                "login.html",
+            };
+
+            for (String templateName : cases) {
+                assertThat(pageInjectionExcluder.isExcluded(templateName)).isFalse();
+            }
+        }
+    }
+}