Halfway through in refactoring the report generation to a separate process running asynchronously of the Express server.

services/reports.js

@@ -0,0 +1,146 @@
+'use strict';
+
+const reports = require('../lib/models/reports');
+const reportTemplates = require('../lib/models/report-templates');
+const lists = require('../lib/models/lists');
+const campaigns = require('../lib/models/campaigns');
+const handlebars = require('handlebars');
+const handlebarsHelpers = require('../lib/handlebars-helpers');
+const _ = require('../lib/translate')._;
+const hbs = require('hbs');
+const vm = require('vm');
+const log = require('npmlog');
+const fs = require('fs');
+const path = require('path');
+const fsTools = require('../lib/fs-tools');
+
+handlebarsHelpers.registerHelpers(handlebars);
+
+function resolveEntities(getter, ids, callback) {
+    const idsRemaining = ids.slice();
+    const resolved = [];
+
+    function doWork() {
+        if (idsRemaining.length == 0) {
+            return callback(null, resolved);
+        }
+
+        getter(idsRemaining.shift(), (err, entity) => {
+            if (err) {
+                return callback(err);
+            }
+
+            resolved.push(entity);
+            return doWork();
+        });
+    }
+
+    setImmediate(doWork);
+}
+
+const userFieldTypeToGetter = {
+    'campaign': (id, callback) => campaigns.get(id, false, callback),
+    'list': lists.get
+};
+
+function resolveUserFields(userFields, params, callback) {
+    const userFieldsRemaining = userFields.slice();
+    const resolved = {};
+
+    function doWork() {
+        if (userFieldsRemaining.length == 0) {
+            return callback(null, resolved);
+        }
+
+        const spec = userFieldsRemaining.shift();
+        const getter = userFieldTypeToGetter[spec.type];
+
+        if (getter) {
+            return resolveEntities(getter, params[spec.id], (err, entities) => {
+                if (spec.minOccurences == 1 && spec.maxOccurences == 1) {
+                    resolved[spec.id] = entities[0];
+                } else {
+                    resolved[spec.id] = entities;
+                }
+
+                doWork();
+            });
+        } else {
+            return callback(new Error(_('Unknown user field type "' + spec.type + '".')));
+        }
+    }
+
+    setImmediate(doWork);
+}
+
+function doneSuccess(id) {
+    // TODO: Mark in the DB as completed + update the date/time
+    // TODO update the report filename in the DB
+
+    process.exit(0);
+}
+
+function doneFail(id) {
+    // TODO: Mark in the DB as failed
+    process.exit(1);
+}
+
+function start(id) {
+    // TODO: Mark in the DB as running
+}
+
+// TODO: Retrieve report task from the DB and run it
+
+function processReport(reportId) {
+    reports.get(reportId, (err, report) => {
+        if (err || !report) {
+            log.error('reports', err && err.message || err || _('Could not find report with specified ID'));
+            doneFail(reportId);
+        }
+
+        reportTemplates.get(report.reportTemplate, (err, reportTemplate) => {
+            if (err) {
+                log.error('reports', err && err.message || err || _('Could not find report template'));
+                doneFail(reportId);
+            }
+
+            resolveUserFields(reportTemplate.userFieldsObject, report.paramsObject, (err, inputs) => {
+                if (err) {
+                    log.error('reports', err.message || err);
+                    doneFail(reportId);
+                }
+
+                const filename = fsTools.nameToFileName(report.name);
+
+                const sandbox = {
+                    require: require,
+                    inputs: inputs,
+                    callback: (err, outputs) => {
+                        if (err) {
+                            log.error('reports', err.message || err);
+                            doneFail(reportId);
+                        }
+
+                        const hbsTmpl = handlebars.compile(reportTemplate.hbs);
+                        const reportText = hbsTmpl(outputs);
+
+                        fs.writeFile(path.join(__dirname, '../protected/reports', filename + '.report'), reportText, (err, reportContent) => {
+                            if (err) {
+                                log.error('reports', err && err.message || err || _('Could not find report with specified ID'));
+                                doneFail(reportId);
+                            }
+
+                            doneSuccess(reportId, filename);
+                            process
+                        });
+                    }
+                };
+
+                const script = new vm.Script(reportTemplate.js);
+                script.runInNewContext(sandbox, {displayErrors: true, timeout: 120000});
+            });
+        });
+    });
+}
+
+processReport(1);