[unomi] 19/25: UNOMI-180 CDP Specification implementation - Add CORS support to get it to work with GraphQL Playground - Managed to execute a query (but doesn't return any data as DataFetchers are not yet implemented !)

[shuber]

This is an automated email from the ASF dual-hosted git repository.

shuber pushed a commit to branch UNOMI-180-CXS-GRAPHQLAPI
in repository https://gitbox.apache.org/repos/asf/unomi.git

commit 2b005ca79d65ffb281cb1d61797b6d9183c515fc
Author: sergehuber <shu...@jahia.com>
AuthorDate: Mon May 13 14:04:34 2019 +0200

    UNOMI-180 CDP Specification implementation
    - Add CORS support to get it to work with GraphQL Playground
    - Managed to execute a query (but doesn't return any data as DataFetchers 
are not yet implemented !)
---
 .../unomi/graphql/internal/CDPSDLServletImpl.java  | 66 +++++++++++++++++-----
 1 file changed, 51 insertions(+), 15 deletions(-)

diff --git 
a/graphql/cxs-impl/src/main/java/org/apache/unomi/graphql/internal/CDPSDLServletImpl.java
 
b/graphql/cxs-impl/src/main/java/org/apache/unomi/graphql/internal/CDPSDLServletImpl.java
index df69692..d56c0d7 100644
--- 
a/graphql/cxs-impl/src/main/java/org/apache/unomi/graphql/internal/CDPSDLServletImpl.java
+++ 
b/graphql/cxs-impl/src/main/java/org/apache/unomi/graphql/internal/CDPSDLServletImpl.java
@@ -37,6 +37,7 @@ import org.osgi.service.component.annotations.Component;
 
 import javax.servlet.ServletConfig;
 import javax.servlet.ServletException;
+import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
@@ -199,24 +200,10 @@ public class CDPSDLServletImpl extends HttpServlet {
             variables = objectMapper.readValue(variableStr, typeRef);
         }
 
+        setupCORSHeaders(req, resp);
         executeGraphQLRequest(resp, query, operationName, variables);
     }
 
-    private void executeGraphQLRequest(HttpServletResponse resp, String query, 
String operationName, Map<String, Object> variables) throws IOException {
-        ExecutionInput executionInput = ExecutionInput.newExecutionInput()
-                .query(query)
-                .variables(variables)
-                .operationName(operationName)
-                .build();
-
-        ExecutionResult executionResult = graphQL.execute(executionInput);
-
-        Map<String, Object> toSpecificationResult = 
executionResult.toSpecification();
-
-        PrintWriter out = resp.getWriter();
-        objectMapper.writeValue(out, toSpecificationResult);
-    }
-
     @Override
     protected void doPost(HttpServletRequest req, HttpServletResponse resp) 
throws ServletException, IOException {
         InputStream bodyStream = req.getInputStream();
@@ -230,9 +217,33 @@ public class CDPSDLServletImpl extends HttpServlet {
             variables = new HashMap<>();
         }
 
+        setupCORSHeaders(req, resp);
         executeGraphQLRequest(resp, query, operationName, variables);
     }
 
+    @Override
+    protected void doOptions(HttpServletRequest req, HttpServletResponse resp) 
throws ServletException, IOException {
+        setupCORSHeaders(req, resp);
+        resp.flushBuffer();
+    }
+
+    private void executeGraphQLRequest(HttpServletResponse resp, String query, 
String operationName, Map<String, Object> variables) throws IOException {
+        if (query == null || query.trim().length() == 0) {
+            throw new RuntimeException("Query cannot be empty or null");
+        }
+        ExecutionInput executionInput = ExecutionInput.newExecutionInput()
+                .query(query)
+                .variables(variables)
+                .operationName(operationName)
+                .build();
+
+        ExecutionResult executionResult = graphQL.execute(executionInput);
+
+        Map<String, Object> toSpecificationResult = 
executionResult.toSpecification();
+        PrintWriter out = resp.getWriter();
+        objectMapper.writeValue(out, toSpecificationResult);
+    }
+
     private Reader getSchemaReader(String resourceUrl) {
         try {
             return new 
InputStreamReader(bundleContext.getBundle().getResource(resourceUrl).openConnection().getInputStream(),
 Charsets.UTF_8.name());
@@ -241,4 +252,29 @@ public class CDPSDLServletImpl extends HttpServlet {
         }
         return null;
     }
+
+    /**
+     * Setup CORS headers as soon as possible so that errors are not 
misconstrued on the client for CORS errors
+     *
+     * @param httpServletRequest
+     * @param response
+     * @throws IOException
+     */
+    public void setupCORSHeaders(HttpServletRequest httpServletRequest, 
ServletResponse response) throws IOException {
+        if (response instanceof HttpServletResponse) {
+            HttpServletResponse httpServletResponse = (HttpServletResponse) 
response;
+            if (httpServletRequest != null && 
httpServletRequest.getHeader("Origin") != null) {
+                httpServletResponse.setHeader("Access-Control-Allow-Origin", 
httpServletRequest.getHeader("Origin"));
+            } else {
+                httpServletResponse.setHeader("Access-Control-Allow-Origin", 
"*");
+            }
+            httpServletResponse.setHeader("Access-Control-Allow-Headers", 
"Origin, X-Requested-With, Content-Type, Accept, X-Apollo-Tracing, test");
+            httpServletResponse.setHeader("Access-Control-Allow-Credentials", 
"true");
+            httpServletResponse.setHeader("Access-Control-Allow-Methods", 
"OPTIONS, POST, GET");
+            // httpServletResponse.setHeader("Access-Control-Max-Age", "600");
+            // 
httpServletResponse.setHeader("Access-Control-Expose-Headers","Access-Control-Allow-Origin");
+            // httpServletResponse.flushBuffer();
+        }
+    }
+
 }