handle zero result, zoom map to bbox if available

bbox.js

@@ -75,8 +75,16 @@ module.exports = function(app, pool) {
             srid: row.srid,
             bboxsrid: row.bboxsrid?row.bboxsrid.match(/BOX\((.*)\)/)[1].split(',').map(coord=>coord.split(' ').map(c=>parseFloat(c))):null
           })
+        } else if (result.rows.length === 0) {
+          res.json({
+            allrows: 0,
+            geomrows: 0,
+            bboxll: null,
+            srid: 0,
+            bboxsrid: null
+          })
         } else {
-          throw(new Error('bbox query did not return 1 row'));
+          throw(new Error('bbox query returned more than 1 row'));
         }
       } catch(err) {
         console.log(err);

public/attrinfo.html

@@ -73,7 +73,7 @@
 
     function initMap()
     {
-        map = new mapboxgl.Map({
+        const mapDefinition = {
             container: 'map',
             "style": {
                 "version": 8,
@@ -98,7 +98,13 @@
                     }
                 ]
             }
-        });
+        }
+        const urlParams = new URLSearchParams(window.location.search);
+        const bboxll = urlParams.get('bboxll');
+        if (bboxll) {
+            mapDefinition.bounds = JSON.parse(bboxll);
+        }
+        map = new mapboxgl.Map(mapDefinition);
         map.on('mousemove', function (e) {
             var features = map.queryRenderedFeatures(e.point).map(function(feature){ return {layer: {id: feature.layer.id, type: feature.layer.type}, properties:(feature.properties)};});
             document.getElementById('info').innerHTML = JSON.stringify(features.map(feature=>feature.properties), null, 2);

public/info.html

@@ -67,7 +67,7 @@
         table.innerHTML = '<tr><th>schema</th><th>name</th><th>geom_column</th><th>srid</th><th>geom_type</th><th>dim</th><th>count</th></tr>' +
             layerInfo.map(item=>`<tr>
                 <td>${item.f_table_schema}</td>
-                <td><a href="tableinfo.html?table=${item.f_table_schema}.${item.f_table_name}&geom_column=${item.f_geometry_column}&srid=${item.srid}&geomtype=${item.type}&dimensions=${item.coord_dimension}&estimated_rows=${item.estimated_rows}">${item.f_table_name}</a></td>
+                <td>${Number(item.estimated_rows)?`<a href="tableinfo.html?table=${item.f_table_schema}.${item.f_table_name}&geom_column=${item.f_geometry_column}&srid=${item.srid}&geomtype=${item.type}&dimensions=${item.coord_dimension}&estimated_rows=${item.estimated_rows}">${item.f_table_name}</a>`:`${item.f_table_name}`}</td>
                 <td>${item.f_geometry_column}</td>
                 <td>${item.srid}</td>
                 <td>${item.type}</td>

public/tableinfo.html

@@ -6,12 +6,21 @@
     <meta http-equiv="X-UA-Compatible" content="ie=edge">
     <title>Info</title>
     <script>
+
+    function addBboxllToLinks(bboxll)
+    {
+        if (bboxll) {
+            document.querySelectorAll('#columns > li > a')
+                .forEach(a=>(a.setAttribute('href', a.getAttribute('href') + '&bboxll='+JSON.stringify(bboxll))))
+        }
+    }
     
     function init() {
         const urlParams = new URLSearchParams(window.location.search);
         const fullTableName = urlParams.get('table');
         const geomType = urlParams.get('geomtype');
-        const geomcolumn = urlParams.get('geom_column')
+        const geomcolumn = urlParams.get('geom_column');
+        let bboxll = null;
         document.querySelector('#tablename').innerHTML = fullTableName;
         const parts = fullTableName.split('.');
         const tableName = (parts.length > 1) ? parts[1] : parts[0];
@@ -35,11 +44,12 @@
             const bbox = document.querySelector('#bbox');
             if (response.ok) {
                 response.json().then(json=> {
+                    addBboxllToLinks(json.bboxll);
                     bbox.innerHTML = `number of rows: ${json.allrows}<br>
                                       number of geometries: ${json.geomrows}<br>
                                       srid: EPSG:${json.srid}<br>
-                                      bbox lon/lat: sw: ${json.bboxll[0][0]},${json.bboxll[0][1]}, ne: ${json.bboxll[1][0]},${json.bboxll[1][1]}<br>
-                                      bbox (EPSG:${json.srid}): ll: ${json.bboxsrid[0][0]},${json.bboxsrid[0][1]}, tr: ${json.bboxsrid[1][0]},${json.bboxsrid[1][1]}<br>
+                                      bbox lon/lat: ${json.bboxll?`sw: ${json.bboxll[0][0]},${json.bboxll[0][1]}, ne: ${json.bboxll[1][0]},${json.bboxll[1][1]}`: 'not defined'}<br>
+                                      bbox (EPSG:${json.srid}): ${json.srid?`ll: ${json.bboxsrid[0][0]},${json.bboxsrid[0][1]}, tr: ${json.bboxsrid[1][0]},${json.bboxsrid[1][1]}`: 'not defined'}<br>
                                       `
                 })
             } else {