My current project is using Node for both frontend and backend and ExpressJS as the middleware.
I have a requirement where I need a feature toggling implementation to introduce some new features in my application. I am using a url parameter, e.g. &featureToggle=true to determine if the code of execution would be the new one or the existing.
Now I have parts in frontend and backend both which need to be changed based on the feature toggle. In the backend I can get the query object separately and extract the url param, similarly also in the frontend module.
Is there a way in which I can use Express to intercept the query param, set a variable value to either true or false based on the feature toggle, and which could be used across both the frontend and backend modules?
with express you can use req.query which gathers the query string sent in the request. You could pass it like this:
localhost:9000/path?&featureToggle=true
the ? is important it tells express that you are creating a query.
if you then place it into a variable:
const query = req.query
you would get the following output:
{ featureToggle: 'true' }
so as you can see it is returning an object. you can check it like so:
if(req.query.featureToggle === 'true'){
runSomeCode();
};
or in your case if you want to run some kind of middleware:
router.get('/', (req, res, next) => {
if(req.query.featureToggle === 'true'){
return next(toggle)
}
};