Server-side support

[paulogr]

Hello!

This function brakes on server side because obviously navigator api isn't part of the NodeJS, but given the name of the function isGeolocationSupported isn't supposed to verify exactly this ?

geolocator/src/core/geolocator.js

Line 1783 in 728785d

static isGeolocationSupported() {

My proposal is to check the type of navigator keyworkd before use it like bellow:

return typeof navigator != 'undefined' && ('geolocation' in navigator);

That way the function will return false and won't break anymore :)

What do you think about?

Thanks

[onury]

Hi. It's technically impossible to get the precise location of a user from server-side via GPS.
On server-side, you can only guess the location from remote address/IP.

This library is only for browser. You cannot/should not use it on server-side.

[paulogr]

I’m sorry but I think you’re missing my point.

I do not want navigator api to work on server, I know it’s impossible. I just want your function do not throw an error but fail gracefully.

I can give you some use cases if you still don't see the problem.

@onury Could you check it again, plz?

Thank you!

[onury]

Some methods of Geolocator would work on server-side. But it's not meant for it. Most of the API make use of Google JS APIs, HTML5 APIs and others that only work on browsers. Why do you want to use this on server?

[paulogr]

In case of use Single Page Application like Angular, React and others there's a feature called Server Side Rendering, that executes the client code on server side to improve speed and features like SEO (Search Engine Optimization).

What's happened with your code, is when I enable the SSR and the code is executed on server side it throw an error to check if geolocation is supported.

My proposal is only to improve how the support of geolocation is checked to not broke the application when it doesn't.

Being aware that your code could be executed on server side even if the feature is not supported makes you lib isomorphic and helps to improve use cases like ssr.

Make sense for you?

[onury]

I didn't do too many SSR apps. I'm assuming you will still make use of geolocator on client-side when page is rendered and passed back to browser. Still, I'm curious why that line got invoked on server.

Rendering your app with SSR, is that the only place Geolocator throws? Even if we change that I'm sure there will be others. Can you change that line and see if it throws in other places? Does it still work on client-side after render?

[paulogr]

The line is invoked on the servers, because the same component/page is executed on both client and server sides. Yes it still works on client even broken on server but something broken on the server side means that the app couldn't generate the server side rendering and so the benefits of performance and seo were broken too.

Yes on SSR is the only place where Geolocator throws an error.

Maybe you're right and another pieces of code could break on server too and yes I can take a look if just changing this line solves the issue or have to have more changes.

If it works, I will send a PR for analyse.

Happy you get the point :)

Thanks

[davidfurlong]

+1 I'm trying to use geocode on the server (Which I don't expect to be specific to browser Web APIs, as calling an external API?) but its giving a ReferenceError: window is not defined. With all the bells and whistles of this library I expected it to work. I don't expect the library authors to have done this, its more of an expectations / documentation thing. I'd appreciate allowing a small disclaimer at the end of the README regarding support for Isomorphic applications / Server side rendering, as this use case has become fairly common nowadays.

Additionally, the solution to my particular issue could be resolved by using an isomorphic fetch library or letting the implementers polyfill it here:

geolocator/src/lib/fetch.js

Line 295 in 728785d

throw new Error('XMLHttpRequest is not supported!');

[onury]

@davidfurlong you're right. Pls see updated readme, Caveats section.

I'm reopening this. Let's see some further discussion and if we can get help on this.