feat: support freemarker template Inheritance halo-dev#534 (halo-dev#537

)

* feat: halo-dev#534

* fix: HashMap initialCapacity

build.gradle

@@ -62,6 +62,7 @@ ext {
     levelDbVersion = '0.12'
     jsonVersion = '20190722'
     fastJsonVersion = '1.2.56'
+    templateInheritance = "0.4.RELEASE"
 }
 
 dependencies {
@@ -70,6 +71,7 @@ dependencies {
     implementation 'org.springframework.boot:spring-boot-starter-web'
     implementation 'org.springframework.boot:spring-boot-starter-undertow'
     implementation 'org.springframework.boot:spring-boot-starter-freemarker'
+    implementation "kr.pe.kwonnam.freemarker:freemarker-template-inheritance:$templateInheritance"
 
     implementation "io.github.biezhi:oh-my-email:$ohMyEmailVersion"
     implementation "cn.hutool:hutool-core:$hutoolVersion"

src/main/java/run/halo/app/config/WebMvcAutoConfiguration.java

@@ -4,6 +4,10 @@
 import freemarker.core.TemplateClassResolver;
 import freemarker.template.TemplateException;
 import freemarker.template.TemplateExceptionHandler;
+import freemarker.template.TemplateModel;
+import kr.pe.kwonnam.freemarker.inheritance.BlockDirective;
+import kr.pe.kwonnam.freemarker.inheritance.ExtendsDirective;
+import kr.pe.kwonnam.freemarker.inheritance.PutDirective;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.boot.jackson.JsonComponentModule;
 import org.springframework.context.annotation.Bean;
@@ -29,7 +33,9 @@
 import run.halo.app.security.resolver.AuthenticationArgumentResolver;
 
 import java.io.IOException;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Properties;
 
 import static run.halo.app.model.support.HaloConst.FILE_SEPARATOR;
@@ -114,6 +120,16 @@ public void addFormatters(FormatterRegistry registry) {
         registry.addConverterFactory(new StringToEnumConverterFactory());
     }
 
+    @Bean
+    public Map<String, TemplateModel> freemarkerLayoutDirectives() {
+        Map<String, TemplateModel> freemarkerLayoutDirectives = new HashMap<>(5);
+        freemarkerLayoutDirectives.put("extends", new ExtendsDirective());
+        freemarkerLayoutDirectives.put("block", new BlockDirective());
+        freemarkerLayoutDirectives.put("put", new PutDirective());
+
+        return freemarkerLayoutDirectives;
+    }
+
     /**
      * Configuring freemarker template file path.
      *
@@ -142,6 +158,13 @@ public FreeMarkerConfigurer freemarkerConfig(HaloProperties haloProperties) thro
         // Set predefined freemarker configuration
         configurer.setConfiguration(configuration);
 
+        // Set layout variable
+        Map<String, Object> freemarkerVariables = new HashMap<>(5);
+
+        freemarkerVariables.put("layout", freemarkerLayoutDirectives());
+
+        configurer.setFreemarkerVariables(freemarkerVariables);
+
         return configurer;
     }