Support search view (#35)

This PR allows theme authors to create a search page respectively.

```release-note
允许主题自定义搜索模板
```

Author: JohnNiang

build.gradle

@@ -16,7 +16,7 @@ repositories {
 }
 
 dependencies {
-    implementation platform('run.halo.tools.platform:plugin:2.10.0-SNAPSHOT')
+    implementation platform('run.halo.tools.platform:plugin:2.17.0-SNAPSHOT')
     compileOnly 'run.halo.app:api'
 
     testImplementation 'run.halo.app:api'
@@ -45,5 +45,5 @@ tasks.named('build').configure {
 }
 
 halo {
-    version = "2.12.0"
+    version = "2.17.0"
 }

src/main/java/run/halo/search/widget/SearchView.java

@@ -0,0 +1,47 @@
+package run.halo.search.widget;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.http.MediaType;
+import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.server.*;
+import reactor.core.publisher.Mono;
+import run.halo.app.search.SearchOption;
+import run.halo.app.search.SearchService;
+
+import java.util.Map;
+
+@Component
+public class SearchView {
+
+    private final SearchService searchService;
+
+    public SearchView(SearchService searchService) {
+        this.searchService = searchService;
+    }
+
+    @Bean
+    RouterFunction<ServerResponse> searchView() {
+        return RouterFunctions.route()
+                .GET("/search", RequestPredicates.accept(MediaType.TEXT_HTML), this::performSearch)
+                .build();
+    }
+
+    private Mono<ServerResponse> performSearch(ServerRequest serverRequest) {
+        var keyword = serverRequest.queryParam("keyword").orElse("");
+        var limit = serverRequest.queryParam("limit")
+                .map(Integer::parseInt)
+                .orElse(10);
+        var includeTypes = serverRequest.queryParams().get("includeTypes");
+        var option = new SearchOption();
+        option.setKeyword(keyword);
+        option.setLimit(limit);
+        option.setFilterExposed(true);
+        option.setFilterPublished(true);
+        option.setFilterRecycled(false);
+        option.setIncludeTypes(includeTypes);
+        var result = searchService.search(option);
+        return ServerResponse.ok().render("search", Map.of(
+                "searchResult", result
+        ));
+    }
+}

src/main/resources/plugin.yaml

@@ -8,7 +8,7 @@ metadata:
     "store.halo.run/app-id": "app-DlacW"
 spec:
   enabled: true
-  requires: ">=2.10.0"
+  requires: ">=2.17.0"
   author:
     name: Halo
     website: https://github.com/halo-dev