Add trait InertiaPageRenderer

src/main/groovy/org/graceframework/plugins/inertia/InertiaPageRenderer.groovy

@@ -0,0 +1,96 @@
+/*
+ * Copyright 2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.graceframework.plugins.inertia
+
+import javax.servlet.http.HttpServletRequest
+import javax.servlet.http.HttpServletResponse
+
+import groovy.transform.CompileStatic
+import groovy.transform.Generated
+
+import grails.artefact.Enhances
+import grails.converters.JSON
+import grails.web.api.WebAttributes
+
+/**
+ * A trait that adds behavior to allow rendering Inertia page object to the response
+ *
+ * @author Michael Yan
+ * @since 0.2
+ */
+@CompileStatic
+@Enhances(['Controller', 'Interceptor'])
+trait InertiaPageRenderer extends WebAttributes {
+
+    @Generated
+    void render(String component, Map props) {
+        webRequest.renderView = false
+
+        if (isInertia()) {
+            renderJson(component, props)
+        }
+        else if (isSsrEnabled()) {
+            renderSsr(component, props)
+        }
+        else {
+            renderHtml(component, props)
+        }
+    }
+
+    private void renderJson(String component, Map props) {
+        HttpServletRequest request = webRequest.currentRequest
+        HttpServletResponse response = webRequest.currentResponse
+
+        String method = request.method
+        String version = grailsApplication.getConfig().getProperty('inertia.version', '1.0')
+        String assetVersion = request.getHeader(InertiaRequest.X_INERTIA_VERSION)
+        if (method.toUpperCase() == 'GET' && version != assetVersion) {
+            response.setHeader(InertiaRequest.X_INERTIA_LOCATION, request.requestURL.toString())
+            response.setStatus(409)
+            return
+        }
+
+        response.setHeader('Vary', 'Accept')
+        response.setHeader(InertiaRequest.X_INERTIA, 'true')
+
+        Map<String, Object> inertiaPage = new LinkedHashMap<>()
+        inertiaPage.component = component
+        inertiaPage.props = props
+        inertiaPage.url = request.requestURL
+        inertiaPage.version = version
+
+        JSON json = new JSON(inertiaPage)
+        json.render response
+    }
+
+    private void renderSsr(String component, Map props) {
+        String ssrUrl = grailsApplication.getConfig().getProperty('inertia.ssr.url', 'http://localhost:13714')
+    }
+
+    private void renderHtml(String component, Map props) {
+
+    }
+
+    private boolean isInertia() {
+        return Boolean.parseBoolean(webRequest.currentRequest.getHeader(InertiaRequest.X_INERTIA))
+    }
+
+    private boolean isSsrEnabled() {
+        String enabled = grailsApplication.getConfig().getProperty('inertia.ssr.enabled', 'false')
+        return Boolean.parseBoolean(enabled)
+    }
+
+}