Pass mu-session-id and mu-authorization-groups headers on queries

Author: erikap

helpers/mu/server.js

@@ -1,3 +1,4 @@
+import httpContext from 'express-http-context';
 import express from 'express';
 import bodyParser from 'body-parser';
 
@@ -13,6 +14,14 @@ app.use('/', function(req, res, next) {
   next();
 });
 
+app.use(httpContext.middleware);
+
+app.use(function(req, res, next) {
+  httpContext.set('request', req);
+  httpContext.set('response', res);
+  next();
+});
+
 const errorHandler = function(err, req, res, next) {
   res.status(err.status || 400);
   res.json({

helpers/mu/sparql.js

@@ -1,21 +1,56 @@
+import httpContext from 'express-http-context';
 import SC2 from 'sparql-client-2';
 const { SparqlClient, SPARQL } = SC2;
 
 //==-- logic --==//
 
 // builds a new sparqlClient
 function newSparqlClient() {
-  return new SparqlClient( process.env.MU_SPARQL_ENDPOINT ).register({
+  let options = {
+    requestDefaults: {
+      headers: {
+        'mu-session-id': httpContext.get('request').get('mu-session-id')
+      }
+    }
+  };
+
+  const authorizationGroups = httpContext.get('response').get('mu-authorization-groups');
+  if (authorizationGroups)
+    options.requestDefaults.headers['mu-authorization-groups'] = authorizationGroups;
+
+  console.log(`Add options on SparqlClient: ${JSON.stringify(options)}`);
+
+  return new SparqlClient(process.env.MU_SPARQL_ENDPOINT, options).register({
     mu: 'http://mu.semte.ch/vocabularies/',
     muCore: 'http://mu.semte.ch/vocabularies/core/',
     muExt: 'http://mu.semte.ch/vocabularies/ext/'
   });
 }
 
 // executes a query (you can use the template syntax)
-function query( queryString ){
+function query( queryString ) {
   console.log(queryString);
-  return newSparqlClient().query( queryString ).execute();
+  return newSparqlClient().queryRaw(queryString).execute().then(response => {
+    const authorizationGroups = response.headers['mu-authorization-groups'];
+    if (authorizationGroups) {
+      httpContext.get('response').setHeader('mu-authorization-groups', authorizationGroups);
+      console.log(`Set mu-authorization-groups header to ${authorizationGroups}`);
+    } else {
+      httpContext.get('response').removeHeader('mu-authorization-groups');
+      console.log('Remove mu-authorization-groups header');
+    }
+
+    function maybeParseJSON(body) {
+      // Catch invalid JSON
+      try {
+        return JSON.parse(body);
+      } catch (ex) {
+        return null;
+      }
+    }
+
+    return maybeParseJSON(response.body);
+  });
 };
 
 // executes an update query

package.json

@@ -20,6 +20,7 @@
     "babel-preset-es2017": "^6.16.0",
     "body-parser": "~1.15.1",
     "express": "^4.14.0",
+    "express-http-context": "~1.0.2",
     "sparql-client-2": "^0.6.0",
     "supervisor": "^0.12.0"
   },