Merge pull request #253 from UW-Macrostrat/keyset-pagination

Keyset Pagination

Author: davenquinn

v2/definitions/strat_name_concepts.ts

@@ -26,15 +26,19 @@ module.exports = function (req, res, next, cb) {
      JOIN macrostrat.refs ON snm.ref_id = refs.id
   */
     }),
-    params = {};
+    params = {},
+    where = [];
 
   if ("all" in req.query) {
     // do nothing
+  } else if (req.query.concept_like) {
+    where.push("lower(name) ILIKE lower(:name)");
+    params["name"] = req.query.concept_like + "%";
   } else if ("concept_name" in req.query) {
-    sql += " WHERE name = ANY(:concept_name)";
+    where.push("name = ANY(:concept_name)");
     params["concept_name"] = req.query.concept_name;
   } else if (req.query.concept_id || req.query.strat_name_concept_id) {
-    sql += " WHERE concept_id = ANY(:concept_id)";
+    where.push("concept_id = ANY(:concept_id)");
     if (req.query.concept_id) {
       params["concept_id"] = larkin.parseMultipleIds(req.query.concept_id);
     } else {
@@ -43,15 +47,28 @@ module.exports = function (req, res, next, cb) {
       );
     }
   } else if (req.query.strat_name_id) {
-    sql +=
-      " WHERE concept_id IN (SELECT concept_id FROM macrostrat.lookup_strat_names WHERE strat_name_id IN (:strat_name_ids))";
+    where.push("concept_id IN (SELECT concept_id FROM macrostrat.lookup_strat_names WHERE strat_name_id IN (:strat_name_ids))");
     params["strat_name_ids"] = larkin.parseMultipleIds(req.query.strat_name_id);
   }
 
+  // pagination
+  const lastId = req.query.last_id ? parseInt(req.query.last_id, 10) : null;
+  const pageSize = req.query.page_size ? parseInt(req.query.page_size, 10) : 5; // defaults to 5
+
+  if (req.query.last_id) {
+    where.push("concept_id > :last_id");
+    params["last_id"] = lastId;
+  }
+
+  if (where.length > 0) {
+    sql += " WHERE " + where.join(" AND ");
+  }
+
   sql += " GROUP BY concept_id, author ORDER BY concept_id";
 
-  if ("sample" in req.query) {
-    sql += " LIMIT 5";
+  if ("sample" in req.query || req.query.last_id) {
+    sql += " LIMIT :page_size";
+    params["page_size"] = pageSize;
   }
 
   larkin.queryPg("burwell", sql, params, function (error, result) {

v2/definitions/strat_names.ts

@@ -8,7 +8,8 @@ module.exports = function (req, res, next, cb) {
   }
 
   var where = [],
-    params = {};
+    params = {},
+    orderBy = [];
 
   if (req.query.rule) {
     if (req.query.rule === "down") {
@@ -123,12 +124,27 @@ module.exports = function (req, res, next, cb) {
     FROM macrostrat.lookup_strat_names l
   `;
 
+  // pagination
+  const lastId = req.query.last_id ? parseInt(req.query.last_id, 10) : null;
+  const pageSize = req.query.page_size ? parseInt(req.query.page_size, 10) : 5; // defaults to 5
+
+  if (req.query.last_id) {
+    where.push("strat_name_id > :last_id");
+    params["last_id"] = lastId;
+    orderBy.push("strat_name_id ASC");
+  }
+
   if (where.length > 0) {
     sql += " WHERE " + where.join(" AND ");
   }
 
-  if ("sample" in req.query) {
-    sql += " LIMIT 5";
+  if (orderBy.length > 0) {
+    sql += " ORDER BY " + orderBy.join(", ");
+  }
+
+  if ("sample" in req.query || req.query.last_id) {
+    sql += " LIMIT :page_size";
+    params["page_size"] = pageSize;
   }
 
   larkin.queryPg("burwell", sql, params, function (error, response) {

v2/defs.ts

@@ -711,6 +711,8 @@
             "retrieve only stratigraphic names linked the specified reference_id (see /defs/refs)",
           all: "return all lithostratigraphic names",
           format: "Desired output format",
+          last_id: "integer, used to paginate results. If specified, will return strat_names with an ID greater than last_id",
+          page_size: "integer, used to paginate results. If specified, will return at most page_size results. Must be paired with last_idd",
         },
         output_formats: ["json", "csv"],
         examples: [
@@ -746,8 +748,11 @@
         parameters: {
           concept_id: "unique id",
           concept_name: "string specifying concept name",
+          concept_like: "lithostratigraphic name concept, with open-ended string matching",
           all: "return all lithostratigraphic names",
           format: "Desired output format",
+          last_id: "integer, used to paginate results. If specified, will return strat_names with an ID greater than last_id",
+          page_size: "integer, used to paginate results. If specified, will return at most page_size results. Must be paired with last_idd",
         },
         output_formats: ["json", "csv"],
         examples: ["api/v2/defs/concept_id?all"],