Add support for csv result format

src/server/index.js

@@ -41,12 +41,19 @@ app.get(`${apiPath}/:resultClass/paginated`, async (req, res, next) => {
   try {
     const data = await getPaginatedResults({
       resultClass: req.params.resultClass,
-      page: parseInt(req.query.page) || null,
+      page: req.query.page == null ? null : req.query.page,
       pagesize: parseInt(req.query.pagesize) || null,
       sortBy: req.query.sortBy || null,
       sortDirection: req.query.sortDirection || null,
       constraints: req.query.constraints == null ? null : JSON.parse(req.query.constraints),
+      resultFormat: req.query.resultFormat == null ? 'json' : req.query.resultFormat
     });
+    // test csv result format
+    // res.writeHead(200, {
+    //   'Content-Type': 'text/csv',
+    //   'Content-Disposition': 'attachment; filename=results.csv'
+    // });
+    // res.end(data);
     res.json(data);
   } catch(error) {
     next(error);
@@ -60,6 +67,7 @@ app.get(`${apiPath}/:resultClass/all`, async (req, res, next) => {
       facetClass: req.query.facetClass || null,
       constraints: req.query.constraints == null ? null : JSON.parse(req.query.constraints),
       variant: req.query.variant || null,
+      resultFormat: req.query.resultFormat == null ? 'json' : req.query.resultFormat
     });
     res.json({
       results: data
@@ -74,6 +82,7 @@ app.get(`${apiPath}/:resultClass/count`, async (req, res, next) => {
     const count = await getResultCount({
       resultClass: req.params.resultClass,
       constraints: req.query.constraints == null ? null : JSON.parse(req.query.constraints),
+      resultFormat: req.query.resultFormat == null ? 'json' : req.query.resultFormat
     });
     res.json({ count });
   } catch(error) {
@@ -88,7 +97,8 @@ app.get(`${apiPath}/:resultClass/instance/:uri`, async (req, res, next) => {
       facetClass: req.query.facetClass || null,
       constraints: req.query.constraints == null ? null : JSON.parse(req.query.constraints),
       variant: req.query.variant || null,
-      uri: req.params.uri
+      uri: req.params.uri,
+      resultFormat: req.query.resultFormat == null ? 'json' : req.query.resultFormat
     });
     // there is always one object in the 'data' array
     res.json(data[0]);
@@ -105,6 +115,7 @@ app.get(`${apiPath}/:facetClass/facet/:id`, async (req, res, next) => {
       sortBy: req.query.sortBy || null,
       sortDirection: req.query.sortDirection || null,
       constraints: req.query.constraints == null ? null : JSON.parse(req.query.constraints),
+      resultFormat: req.query.resultFormat == null ? 'json' : req.query.resultFormat
     });
     res.json(data);
   } catch(error) {
@@ -134,6 +145,7 @@ app.get(`${apiPath}/search`, async (req, res, next) => {
       longMin: longMin,
       latMax: latMax,
       longMax: longMax,
+      resultFormat: req.query.resultFormat == null ? 'json' : req.query.resultFormat
     });
     res.json(data);
   } catch(error) {

src/server/sparql/FacetResults.js

@@ -24,7 +24,8 @@ export const getPaginatedResults = async ({
   pagesize,
   constraints,
   sortBy,
-  sortDirection
+  sortDirection,
+  resultFormat
 }) => {
   const data = await getPaginatedData({
     resultClass,
@@ -32,20 +33,26 @@ export const getPaginatedResults = async ({
     pagesize,
     constraints,
     sortBy,
-    sortDirection
+    sortDirection,
+    resultFormat
   });
-  return {
-    pagesize: pagesize,
-    page: page,
-    results: data
-  };
+  if (resultFormat === 'json') {
+    return {
+      pagesize: pagesize,
+      page: page,
+      results: data
+    };
+  } else {
+    return data;
+  }
 };
 
 export const getAllResults = ({
   // resultClass, // TODO: handle other classes than manuscripts
   facetClass,
   constraints,
-  variant
+  variant,
+  resultFormat
 }) => {
   let q = '';
   let filterTarget = '';
@@ -80,12 +87,13 @@ export const getAllResults = ({
   // if (variant == 'productionPlaces') {
   //   console.log(prefixes + q)
   // }
-  return runSelectQuery(prefixes + q, endpoint, makeObjectList);
+  return runSelectQuery(prefixes + q, endpoint, makeObjectList, resultFormat);
 };
 
 export const getResultCount = ({
   resultClass,
-  constraints
+  constraints,
+  resultFormat
 }) => {
   let q = countQuery;
   q = q.replace('<FACET_CLASS>', facetConfigs[resultClass].facetClass);
@@ -100,7 +108,7 @@ export const getResultCount = ({
       facetID: null
     }));
   }
-  return runSelectQuery(prefixes + q, endpoint, mapCount);
+  return runSelectQuery(prefixes + q, endpoint, mapCount, resultFormat);
 };
 
 const getPaginatedData = ({
@@ -109,7 +117,8 @@ const getPaginatedData = ({
   pagesize,
   constraints,
   sortBy,
-  sortDirection
+  sortDirection,
+  resultFormat
 }) => {
   let q = facetResultSetQuery;
   const facetConfig = facetConfigs[resultClass];
@@ -163,8 +172,8 @@ const getPaginatedData = ({
       resultSetProperties = '';
   }
   q = q.replace('<RESULT_SET_PROPERTIES>', resultSetProperties);
-  // console.log(prefixes + q)
-  return runSelectQuery(prefixes + q, endpoint, makeObjectList);
+  console.log(prefixes + q);
+  return runSelectQuery(prefixes + q, endpoint, makeObjectList, resultFormat);
 };
 
 export const getByURI = ({
@@ -172,7 +181,8 @@ export const getByURI = ({
   facetClass,
   constraints,
   //variant,
-  uri
+  uri,
+  resultFormat
 }) => {
   let q;
   switch (resultClass) {
@@ -194,5 +204,5 @@ export const getByURI = ({
   // if (variant === 'productionPlaces') {
   //   console.log(prefixes + q)
   // }
-  return runSelectQuery(prefixes + q, endpoint, makeObjectList);
+  return runSelectQuery(prefixes + q, endpoint, makeObjectList, resultFormat);
 };

src/server/sparql/FacetValues.js

@@ -25,6 +25,7 @@ export const getFacet = ({
   sortBy,
   sortDirection,
   constraints,
+  resultFormat
 }) => {
   const facetConfig = facetConfigs[facetClass][facetID];
   // choose query template and result mapper:
@@ -104,7 +105,7 @@ export const getFacet = ({
   // if (facetID == 'productionPlace') {
   //   console.log(prefixes + q)
   // }
-  return runSelectQuery(prefixes + q, endpoint, mapper);
+  return runSelectQuery(prefixes + q, endpoint, mapper, resultFormat);
 };
 
 const generateSelectedBlock = ({

src/server/sparql/SparqlApi.js

 import axios from 'axios';
 import querystring from 'querystring';
-
-const defaultSelectHeaders = {
-  'Content-Type': 'application/x-www-form-urlencoded',
-  'Accept': 'application/sparql-results+json; charset=utf-8'
-};
 // const defaultConstructHeaders = {
 //   'Content-Type': 'application/x-www-form-urlencoded',
 //   'Accept': 'text/turtle'
 // };
 
-export const runSelectQuery = async (query, endpoint, resultMapper) => {
+export const runSelectQuery = async (query, endpoint, resultMapper, resultFormat) => {
+  let MIMEtype = resultFormat === 'json'
+    ? 'application/sparql-results+json; charset=utf-8'
+    : 'text/csv; charset=utf-8';
+  const headers = {
+    'Content-Type': 'application/x-www-form-urlencoded',
+    'Accept': MIMEtype
+  };
   try {
     const response = await axios({
       method: 'post',
-      headers: defaultSelectHeaders,
+      headers: headers,
       url: endpoint,
       data: querystring.stringify({ query }),
     });
-    return resultMapper(response.data.results.bindings);
+    if (resultFormat === 'json') {
+      return resultMapper(response.data.results.bindings);
+    } else {
+      return response.data;
+    }
+
   } catch(error) {
     if (error.response) {
     // The request was made and the server responded with a status code