How to geolocate users with Cookie Consent
Architecture
Cookie Consent contains three modules named Popup, Law and Location.
- Popup can be used on it’s own regardless of it’s location, and contains any and all functionality for displaying a popup on screen.
- Law accepts the popup options and a country code. Using the country code it modifies the popup options, enabling/disabling certain functionality in order to comply with the law specified by that country
- Location is simply a tool for getting the two letter country code that the user is in.
Together, these modules: get the country code, apply the law specific to that country, and display the popup (if necessary)
In code form, a service looks like this:
{
url: <string> //The location of the service API
isScript: <boolean>, //Whether to use a script tag or a XMLHttpRequest
data: <object>, //Useful if the service requires post data
headers: <array>, //Useful for setting service specific header
callback: <function(done, response)>, //A handler for understanding the response
}
The callback provides a done callback. If you need to make additional requests, call done with the country code when you’re finished. Otherwise, just return the country code
Example:{
url: '//example-service/script.js',
isScript: true,
callback: function (done, response) {
// We just downloaded the 'script.js' which defined a third party object.
if (!window.MyService) {
done(new Error('The JavaScript file failed to download and define MyService'));
}
MyService.locateMe(function(response){
done({code: response.countryCode});
}, function(err){
done(new Error(err));
});
},
}
Services
In order to find the location, Cookie Consent uses third-party location services. These third-party services usually provide an API that can be accessed over the internet.
To integrate a new service, you need to define the service location, the type of request (XMLHttpRequest vs <script>) and how the tool should interpret the response.
To do this, define a new service like so:
cookieconsent.initialise({
...popupOptions,
location: {
serviceDefinitions: {
mynewservice: function(options) {
return {
url: '//example-service.com/json',
callback: function(done, response) {
// This function must parse the 'response' and return the country code, or fail.
// If this function doesn't fail correctly, then the next service will not run.
// Therefore, it's generally best to add a <em>try {...} catch () {...}</em> block
try {
var json = JSON.parse(response);
if (json.countryCode) {
return {code: json.countryCode}
}
throw 'Could not find a country code in the response';
} catch (err) {
return new Error('Invalid response (' + err + ')');
}
},
};
},
},
services: [
'mynewservice'
]
}
});
Above, you can see that we first define our service, then we use it by adding it to the services array. We can add it simply by passing the name of it as a string.
Some service definitions may be more complicated though, and require configuration.
To do this, you can pass an object instead:services: [
{
name:'mynewservice',
mySpecialOption: 'some value',
KEY: 'uUCGtoyeiH5gsm3Wn2cp9D1Z1deHcpBG8ySA4hYBcQd20Z4C6AwGKqln7mtEfGN'
}
]
Then, when defining your service, the options are passed through like so:
mynewservice: function(options) {
// `options.mySpecialValue` and `options.KEY` now exist
return {
url: '//someurl.com?apiKey='+options.KEY
// ...serviceDefinition
};
}
As well as passing an object with options into the ‘services’ array, you can also pass a function that returns an object, just because.
Notes
Above, we integrated options.KEY with the url by simply appending the two string. If you’re lazy, there is an option called interpolateUrl which will automatically interpolate a string with the values of an object. Use it like so:
serviceDefinitions: {
mynewservice: function(options) {
return {
url: '//example-service.com/json?key={api_key}&someValue=1&callback={callback}',
isScript: true,
// use this flag to tell the tool to download
// the resource as a script tag (using JSONP)
callback: function(done, response) {
// handle response
},
};
},
},
services: [
{
name: 'mynewservice',
interpolateUrl: {
api_key: 'uUCGtoyeiH5gsm3Wn2cp9D1Z1deHcpBG8ySA4hYBcQd20Z4C6AwGKqln7mtEfGN'
}
}
]
The {callback} string can be used in the URL to automatically write the JSONP callback. It is appended with Date.now() to prevent global namespace collisions.