This example shows how to use 51Degrees device detection to process a file containing many User-Agents.
This example is available in full on GitHub.
This example requires a local data file. The free 'Lite' data file can be acquired by pulling the git submodules under this repository (run `git submodule update --recursive`) or from the device-detection-data GitHub repository.
The Lite data file is only used for illustration, and has limited accuracy and capabilities. Find out about the more capable data files that are available on our pricing page
This example require module 'n-readlines' to operate. Please install the module before running the example, by using the following command:
npm install n-readlines
Expected output:
Output written to [...]/batch-processing-example-results.csv
/* *********************************************************************
* This Original Work is copyright of 51 Degrees Mobile Experts Limited.
* Copyright 2019 51 Degrees Mobile Experts Limited, 5 Charlotte Close,
* Caversham, Reading, Berkshire, United Kingdom RG4 7BY.
*
* This Original Work is licensed under the European Union Public Licence (EUPL)
* v.1.2 and is subject to its terms as set out below.
*
* If a copy of the EUPL was not distributed with this file, You can obtain
* one at https://opensource.org/licenses/EUPL-1.2.
*
* The 'Compatible Licences' set out in the Appendix to the EUPL (as may be
* amended by the European Commission) shall be deemed incompatible for
* the purposes of the Work and the provisions of the compatibility
* clause in Article 5 of the EUPL shall not apply.
*
* If using the Work as, or as part of, a network application, by
* including the attribution notice(s) required under Article 5 of the EUPL
* in the end user terms of the application under an appropriate heading,
* such notice(s) shall fulfill the requirements of that article.
* ********************************************************************* */
const events = require('events');
const LineReader = require('n-readlines');
require((process.env.directory || __dirname) +
'/../../../deviceDetectionOnPremisePipelineBuilder');
// In this example, by default, the 51degrees "Lite" file needs to be in the
// fiftyone.devicedetection.onpremise/device-detection-cxx/device-detection-data,
// or you may specify another file as a command line parameter.
//
// Note that the Lite data file is only used for illustration, and has
// limited accuracy and capabilities.
// Find out about the Enterprise data file on our pricing page:
// https://51degrees.com/pricing
const LITE_V_4_1_HASH = '51Degrees-LiteV4.1.hash';
const UA_CSV = '20000 User Agents.csv';
// Load in a datafile
const sliceLen = process.env.JEST_WORKER_ID === undefined ? 2 : process.argv.length;
const args = process.argv.slice(sliceLen);
// Use the supplied path for the data file or find the lite
// file that is included in the repository.
// Load in a user-agents file
const uafile = args.length > 1 ? args[1] : ExampleUtils.findFile(UA_CSV);
// Construct output file path
const outputFile = (process.env.directory || __dirname) +
'/batch-processing-example-results.csv';
// Check if files exists
const fs = require('fs');
if (!fs.existsSync(datafile)) {
console.error('Failed to find a device detection ' +
'data file. Make sure the device-detection-data ' +
'submodule has been updated by running ' +
'`git submodule update --recursive`.');
throw ("No data file at '" + datafile + "'");
}
if (!fs.existsSync(uafile)) {
console.error('Failed to find a User-Agents ' +
'file. Make sure the device-detection-data ' +
'submodule has been updated by running ' +
'`git submodule update --recursive`.');
throw ("No User-Agents file at '" + datafile + "'");
}
// Maximum number of User-Agents to be processed
const maxUserAgents = 20;
// Create a writeStream for output file
const writeStream = fs.createWriteStream(outputFile);
// Create an event listener for when User-Agents
// have been processed
const eventEmitter = new events.EventEmitter();
eventEmitter.on('FinishProcessing', () => {
if (typeof deleteOutputFile !== 'undefined') {
if (fs.existsSync(outputFile)) {
fs.unlink(outputFile, function (err) {
if (err) throw err;
console.log('Delete output file ' + outputFile);
});
}
}
console.log('Output written to ' + outputFile);
});
let userAgentsProcessed = 0;
// Create the device detection pipeline with the desired settings.
performanceProfile: 'MaxPerformance',
dataFile: datafile,
autoUpdate: false
}).build();
// To monitor the pipeline we can put in listeners for various log events.
// Valid types are info, debug, warn, error
pipeline.on('error', console.error);
// Here we make a function that gets a userAgent as evidence and
// uses the Device Detection Engine to obtain the properties of the
// device and output it to file.
const processUA = async function (userAgent) {
// Create a FlowData element
// This is used to add evidence and process it through the
// FlowElements in the Pipeline.
const flowData = pipeline.createFlowData();
// Add the User-Agent as evidence
flowData.evidence.add('header.user-agent', userAgent);
// Run process on the flowData (this returns a promise)
await flowData.process();
// Construct the output line
const ismobile = flowData.device.ismobile;
const platformname = flowData.device.platformname;
const platformversion = flowData.device.platformversion;
const outputLine = userAgent +
', ' + (ismobile.hasValue ? ismobile.value : '') +
', ' + (platformname.hasValue ? platformname.value : '') +
', ' + (platformversion.hasValue ? platformversion.value : '') +
'\n';
writeStream.write(outputLine);
// Increment the number of User-Agent processed and
// signal if the required number has been reached
if (++userAgentsProcessed === maxUserAgents) {
eventEmitter.emit('FinishProcessing');
}
};
// Create lines reader for the User-Agents file
const liner = new LineReader(uafile);
let line;
let linesCounter = 0;
// Start reading User-Agents from file
while ((line = liner.next()) && linesCounter++ < maxUserAgents) {
processUA(line.toString('utf8').replace(/\r?\n|\r/g, ''));
}
// Close the line reader
liner.close();