initial commit

Author: anneb

.gitignore

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+node_modules
+config/dbconfig.json
+public/files

config/dbconfig.example.json

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+{
+    "host": "host.example.com",
+    "user": "dbuser",
+    "password": "dbpassword",
+    "database": "dbname",
+    "ssl": true,
+    "port": 5432,
+    "max": 20,
+    "idleTimeoutMillis": 30000,
+    "connectionTimeoutMillis": 2000
+}

config/pgserver.json

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+{
+    "port": 8090
+}

login.js

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+function login(app) {
+
+/**
+ * @swagger
+ *
+ * /login:
+ *   post:
+ *     description: Login to the application
+ *     produces:
+ *       - application/json
+ *     parameters:
+ *       - name: username
+ *         description: Username to use for login.
+ *         in: formData
+ *         required: true
+ *         type: string
+ *       - name: password
+ *         description: User's password.
+ *         in: formData
+ *         required: true
+ *         type: string
+ *     responses:
+ *       200:
+ *         description: login
+ */
+app.post('/login', (req, res) => {
+    // Your implementation comes here ...
+  });
+app.get('/login', (req, res) => {
+  res.json({result:"ok"})
+});
+}
+module.exports = login

mvt.js

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+const sm = require('@mapbox/sphericalmercator');
+const fs = require('fs');
+const {Pool} = require('pg');
+const fsPromises = fs.promises;
+const path = require('path');
+const merc = new sm({
+  size: 256
+})
+
+const dbconfig = require('./config/dbconfig.json');
+
+const pool = new Pool(dbconfig);
+
+pool.connect();
+
+// route query
+const sql = (params, query) => {
+    let bounds = merc.bbox(params.x, params.y, params.z, false, '900913')
+  
+    return `
+    SELECT 
+      ST_AsMVT(q, '${params.table}', 4096, 'geom')
+    
+    FROM (
+      SELECT
+        ${query.columns ? `${query.columns},` : ''}
+        ST_AsMVTGeom(
+          ST_Transform(${query.geom_column}, 3857),
+          ST_MakeBox2D(ST_Point(${bounds[0]}, ${bounds[1]}), ST_Point(${
+      bounds[2]
+    }, ${bounds[3]}))
+        ) geom
+  
+      FROM (
+        SELECT
+          ${query.columns ? `${query.columns},` : ''}
+          ${query.geom_column},
+          srid
+        FROM 
+          ${params.table},
+          (SELECT ST_SRID(${query.geom_column}) AS srid FROM ${
+      params.table
+    } LIMIT 1) a
+          
+        WHERE       
+          ST_transform(
+            ST_MakeEnvelope(${bounds.join()}, 3857), 
+            srid
+          ) && 
+          ${query.geom_column}
+  
+          -- Optional Filter
+          ${query.filter ? `AND ${query.filter}` : ''}
+      ) r
+  
+    ) q
+    `
+  }
+  
+
+// TODO add flat-cache
+
+module.exports = function(app) {
+ /**
+ * @swagger
+ *
+ * /data/{datasource}/mvt/{z}/{x}/{y}?columns={columns}:
+ *   get:
+ *     description: get mapbox vector tile (mvt)
+ *     produces:
+ *       - application/x-protobuf
+ *     parameters:
+ *       - name: datasource
+ *         description: name of postgis datasource 
+ *         in: path
+ *         required: true
+ *         type: string
+ *       - name: z
+ *         description: zoom level of tile
+ *         in: path
+ *         required: true
+ *         type: number
+ *       - name: x
+ *         description: x value (column number) of tile
+ *         in: path
+ *         required: true
+ *         type: number
+ *       - name: y
+ *         description: y value (row number) of tile
+ *         in: path
+ *         required: true
+ *         type: number
+ *       - name: geom_column
+ *         description: name of geometry column (default 'geom')
+ *         in: query
+ *         default: geom
+ *         required: false
+ *       - name: columns
+ *         description: optional comma seperated list of attribute columns to be added to the mvt geometries
+ *         in: query
+ *         required: false
+ *         type: string
+ *         default: null
+ *         allowEmptyValue: true
+ *     responses:
+ *       200:
+ *         description: vector tile
+ *       204:
+ *         description: no data (empty tile)
+ *       422:
+ *         description: invalid datasource or columnname
+ */
+    app.get('/data/:datasource/mvt/:z/:x/:y', async (req, res)=>{
+        if (!req.query.geom_column) {
+            req.query.geom_column = 'geom';
+        }
+        req.params.table = req.params.datasource;
+        const sqlString = sql(req.params, req.query);
+        console.log(sqlString);
+        try {
+            const result = await pool.query(sqlString);
+            const mvt = result.rows[0].st_asmvt
+            if (mvt.length === 0) {
+                res.status(204)
+            }
+            res.header('Content-Type', 'application/x-protobuf').send(mvt);
+        } catch(err) {
+            console.log(err);
+            switch (err.code) {
+                case '42P01':
+                    err.name = `table ${req.params.table} does not exist`;
+                    break;
+                case '42703':
+                    err.name = `column does not exist`;
+                    break;
+            }
+            res.status(422).json({error:err})
+        }
+    })
+}