`?_k=*` in the query string

[alexreardon]

After updating to the latest version I am getting ?_k=* (eg ?_k=umhx1s) added to end of my urls. A few questions:

1. What is this for?
2. Is there a way it can be removed? I like my urls to be pretty.

[gaearon]

Please see here.

[alexreardon]

My apologies. I also found more info on in here:
https://github.com/rackt/react-router/blob/master/docs/basics/Histories.md#what-is-that-_kckuvup-junk-in-the-url

[DanielSundberg]

@gaearon, could you elaborate on how your link relate to this issue? I'm not using rackt in my app...

[knowbody]

@DanielSundberg this link is to History documentation which is used by React Router. Rackt is an organization under which we keep React Router, History and many more open source projects...

[DanielSundberg]

Ok thanks for the clarification. Perhaps there should be something about this in the upgrade guide? (https://github.com/rackt/react-router/blob/master/UPGRADE_GUIDE.md). We haven't used the history feature of react-router before and I was very confused when I saw that this was added to the url.

[knowbody]

it's already here I don't see the point of repeating stuff like this everywhere. Upgrade guide says about the use of the new History, and I think that's enough. Added ?_k=cvssfs it's a small detail, which can be find explained in the part about the History specifically.

[DanielSundberg]

I don't think that adding a new parameter to the url is a small detail. And I would not expect users of a component to read through all documentation when upgrading. I did google this and I came across this issue before the documentation link in the result list.

[knowbody]

@DanielSundberg if it brings so much confusion and you don't mind please send the PR for the change in the Upgrade Guide

[johnnyreilly]

It looks like it's opt-outable here but this was hard to find and involves another package.

For what it's worth, our team was evaluating upgrading to React 0.14.0 and React Router 1.0.0 but has now decided to hold off mainly because of this - our app doesn't have any state data we need persisted and so this feature has no value for us. Unfortunately for us, adding extra dependencies (history/lib/createHashHistory) is a somewhat arduous process.

I'll try and send a docs PR for the upgrade guide.

[knowbody]

@johnnyreilly Are you saying that adding three extra lines of code is an arduous process?

[just-boris]

I don't understand why when I am using HTML5 pushState it can work without extra _k, but in case of hash navigation it is recommended to have extra query key in addition to path?

In other words why http://localhost:3000/projects is fine, but with hash it should be http://localhost:3000/#/projects?_k=zb7sg9