make component isomorphic friendly

[gregory90]

Moved touch detection to componentDidMount so we won't run that code on the server.

[balloob]

Using typeof window === 'object' should already make sure that that code is not executed on the server.

[gregory90]

Problem lies elsewhere. If you do npm install react-sidebar you get commit 551068b4821665a9592aafac3b3cfb6e0743b81d with old dist-modules(updated in commit acd8d00d120f911808e46207783522e06850760b).

Sorry for the confusion.

[balloob]

Updated dist-modules and pushed to master, 0643894, will push a new npm release too

[gregory90]

Thanks!

[elliottsj]

Setting dragSupported in the constructor leads to an issue where the server-rendered markup differs from the client render. On the server, dragSupported starts as false, so useTouch === false and no dragHandle is rendered. On the client, dragSupported starts as true, so useTouch === true and React tries to render the dragHandle, but this error is raised due to the different markup:

Unhandled promise rejection Error: You're trying to render a component to the document using server rendering but the checksum was invalid. This usually means you rendered a different component type or props on the client from the one on the server, or your render() methods are impure. React cannot handle this case due to cross-browser quirks by rendering at the document root. You should look for environment dependent code in your components and ensure the props are the same client and server side:
 (client) a-reactid="29"><div style="z-index:1;pos
 (server) a-reactid="29"><div data-reactid="30"><s
    at invariant (webpack:///./~/fbjs/lib/invariant.js?:38:15)
    at Object.ReactMount._mountImageIntoNode (webpack:///./~/react/lib/ReactMount.js?:451:91)
    at Object.wrapper [as _mountImageIntoNode] (webpack:///./~/react/lib/ReactPerf.js?:66:21)
    at mountComponentIntoNode (webpack:///./~/react/lib/ReactMount.js?:110:14)
    at ReactReconcileTransaction.Mixin.perform (webpack:///./~/react/lib/Transaction.js?:136:20)
    at batchedMountComponentIntoNode (webpack:///./~/react/lib/ReactMount.js?:124:15)
    at ReactDefaultBatchingStrategyTransaction.Mixin.perform (webpack:///./~/react/lib/Transaction.js?:136:20)
    at Object.ReactDefaultBatchingStrategy.batchedUpdates (webpack:///./~/react/lib/ReactDefaultBatchingStrategy.js?:63:19)
    at Object.batchedUpdates (webpack:///./~/react/lib/ReactUpdates.js?:97:20)
    at Object.ReactMount._renderNewRootComponent (webpack:///./~/react/lib/ReactMount.js?:277:18

The client should have dragSupported start as false to properly reconcile with the server markup, as in this PR.

[elliottsj]

I've re-created this PR as #44, retaining @gregory90's original commit