This example shows how to return Javascript to obtain further evidence for 51Degrees' on-premise device detection in Nginx. 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

Properties required for this example are not included in the free Lite file, so a data file that includes ScreenPixelsWidth and ScreenPixelsWidthJavascript need to be obtained from configurator.

Before using the example, update the followings:

Remove this 'how to' guide block.
Update the file path specifed in 51D_file_path with the actual file path.
Replace the nginx.conf with this file or run Nginx with -c option pointing to this file.
Create a static file overrides in the Nginx document_root.

In a Linux environment, once Nginx has started, open the index.html in a browser.

The index.html send a request to the /51D.js endpoint to obtain the javascript and execute it as below:

Then use the obtained screen pixels width to send back to the /overrides endpoint. The full details can be seen in the index.html.

The Javascript can be seen by running the below command.

$ curl localhost:8080/51D.js -A "Mozilla/5.0 (iPhone; CPU iPhone OS 7_1 like Mac OS X) AppleWebKit/537.51.2 (KHTML, like Gecko) Version/7.0 Mobile/11D167 Safari/9537.53"

Expected display after open the index.html in the browser is:

Screen Pixels Width: 1920

The number should be the screen pixels width of your machine.

NOTE: All the lines above, this line and the end of comment block line after this line should be removed before using this example.

worker_processes 4;

load_module modules/ngx_http_51D_module.so;

events {

worker_connections 1024;

}

# // Snippet Start

http {

## Set the data file for the 51Degrees module to use ##

51D_file_path ./device-detection-cxx/device-detection-data/51Degrees-LiteV4.1.hash;

server {

listen 8888;

location /overrides {

## Get screen pixels width. Use matched all so override evidence can be processed ##

51D_match_all x-screenpixelswidth ScreenPixelsWidth;

## Add to response headers for easy viewing. ##

add_header Access-Control-Allow-Origin *;

add_header Access-Control-Allow-Heaaders *;

add_header Access-Control-Expose-Headers *;

add_header x-screenpixelswidth $http_x_screenpixelswidth;

}

location /51D.js {

## Get the javascript from ScreenPixelsWidthJavascript property ##

51D_get_javascript_single ScreenPixelsWidthJavascript;

## Since the URL location does not actually exist, an error will be logged, ##

## disable file not found error logging ##

log_not_found off;

}

# // Snippet End

51Degrees Device Detection Nginx 4.4

hash/jsExample/javascript.conf