The basic difference is that the hashHistory uses URLs like: http://myurl.com/#page/another_page/another_page

With BrowserHistory you get normal urls (no hash): http://myurl.com/page/another_page/another_page

First difference:

They are using different WEB APIs. 
`&lt;HashRouter&gt;` uses and reads the hash from URL, 
`&lt;BrowserRouter&gt;` uses `window.history` WEB API.

Second difference:

`&lt;HashRouter&gt;` is used for static one-page website. Ideal for browser based projects.
`&lt;BrowserRouter&gt;` is used for dynamic website. Should be used when you have a server that will handle dynamic requests (knows how to respond to any possible URL).


I don&#39;t think the question was asking for differences in the format, but rather technical. Hence sharing this answer here with a technical difference: https://stackoverflow.com/a/42157741/2445694

Basically the browser don&#39;t send the url after the #

So suppose that a website restricted areas for members and admins. A user navigates to /member, and is prompted for logging in. However the server won&#39;t know if the user was trying to access /admin or /member before getting on the log in page, so after logging in the server don&#39;t know where to redirect. 




1) Browser’s history’s location array contains more than just the locations that have been visited within our application. Allowing access to this list would leak information about a user’s browsing history that websites should not be allowed access to.

2) Browser history creates location objects whose pathname is the URL’s full pathname. However, you can specify a basename for a history, in which case a portion of the full pathname will be effectively ignored.

3) Browser History in static file server will have one real location on our server to fetch our HTML from while Hash history uses the hash section of the URL to set and read locations. 

4) Hash History is reliant as it store all of the path information in the hash of a URL. 

I&#39;m developing a google chrome **packaged** app, when I put Sandbox in the `manifest.json`:

     {
      &quot;manifest_version&quot;: 2,
      &quot;name&quot;: &quot;WM32216&quot;,
      &quot;version&quot;: &quot;2.1&quot;,
      &quot;minimum_chrome_version&quot;: &quot;23&quot;,
      &quot;permissions&quot;:[&quot;webview&quot;, &quot;https://ajax.googleapis.com/*&quot;],
      &quot;sandbox&quot;:{
          &quot;pages&quot;:[&quot;index.html&quot;]
      },
      &quot;app&quot;: {
        &quot;background&quot;: {
          &quot;scripts&quot;: [&quot;main.js&quot;]
        }
      }
    }

An `onclick` event on my anchor tag works, and the flow of the app is complete EXCEPT THAT, icons from a CSS stylesheet don&#39;t load.

I got an `error` from the console that 

`File not found` ,

but those are just **fonts** so it&#39;s fine with me, 

The big problem is that, the video in the iframe doesn&#39;t play and I got additional error prior to the Font which are: 

&gt; VIDEOJS: ERROR: (CODE:4 MEDIA_ERR_SRC_NOT_SUPPORTED) The media could not be loaded, either because the server or network failed or because the format is not supported. 
&gt;
&gt; Not allowed to load local resource: blob:null/b818b32c-b762-4bd9-...
 
When I remove the sandbox in the manifest.json file, everything is good no errors in the console about the font, 

BUT when I **hit/click my anchor tag** that has a click event to load a new function in the js  I&#39;m getting the following **Console Error** :

&gt; Refused to execute inline event handler because it violates the following Content Security Policy directive: &quot;default-src &#39;self&#39; blob: filesystem: chrome-extension-resource:&quot;. Either the &#39;unsafe-inline&#39; keyword, a hash (&#39;sha256-...&#39;), or a nonce (&#39;nonce-...&#39;) is required to enable inline execution. Note also that &#39;script-src&#39; was not explicitly set, so &#39;default-src&#39; is used as a fallback.


Sorry for the very long detail,

I just need help with this because I&#39;m stuck here for 3 days already.

Refused to execute inline event handler because it violates CSP. (SANDBOX)

Trying to get a bit more functionality out of Atom&#39;s spell checker and right now the false positives are making it less than useful.

How can I add a word to Atom&#39;s dictionary so it no longer shows up as misspelled? 

How to add words to Atom&#39;s spell checker dictionary?

I have googled quite some bit, but I didn&#39;t find a clear answer to the following question: What is the difference between hashHistory and browserHistory in react-router?

What is the difference between hashHistory and browserHistory in react router?

<p>I have googled quite some bit, but I didn't find a clear answer to the following question: What is the difference between hashHistory and browserHistory in react-router?</p>


How can I import all types from certain file?

Let&#39;s say I have `myClass.ts` and `otherClass.ts`.
I want to import all classes from `otherClass.ts`.

I&#39;ve seen few syntaxes for imports.

    import ClassA, { ClassB, ClassC } from &#39;otherClass&#39;;

    import * as foo from &#39;otherClass&#39;;

    import foo = require(&#39;otherClass&#39;);

    import &#39;rxjs/Rx&#39;;


1. The first needs me to list everything. I&#39;d like to import all types.

2. The second syntax needs the namespace prefix: `foo.ClassA`.

3. I understand that the last one is TypeScript 1.4, but still supported.

Is there something like the following?

    import * from &quot;otherClass&quot;;
    ...
       var x = new ClassA()

Also, what&#39;s the meaning of the `{ ... }` and some of the types being outside and some inside? 

The [documentation][1] doesn&#39;t hint anything such.

  [1]: https://www.typescriptlang.org/docs/handbook/modules.html

TypeScript / JavaScript - import all types

I&#39;m looking at some code from a coworker wrote and she&#39;s using the `@` symbol in require statements. This is the first line of one of these files:

    var restServer = require(&#39;@company/config&#39;)

When I try to run this code, I get an error:

&gt; `Error: Cannot find module &#39;@company/config&#39;`

Which I frankly expect, there&#39;s nothing that looks like this in my directory for require to recognize! It seems like there&#39;s some magic going on here, which I hate.

All I can guess is that either this is some obscure npm or Node trick that I haven&#39;t been exposed to, or maybe that there&#39;s some other dark art of configuration that I&#39;m not getting. Any info appreciated, even if it&#39;s just an explanation of how `@` works with require.

Other ideas: Chef is involved somewhere in this whole thing, so that might be relevant. 

**Update**: 99% certain this is an issue with the way `npm config` works at this point, but still unsure of how to go about fixing it. 

**Update2** based on some stuff I uncovered: 

    Dereks-MacBook-Pro:project-dir derekjanni$ npm config set //registry.npmjs.org/:authtoken $SECRET_TOKEN

    Dereks-MacBook-Pro:project-dir derekjanni$ npm install
    npm ERR! Darwin 15.0.0
    npm ERR! argv &quot;/usr/local/Cellar/node/5.5.0/bin/node&quot; &quot;/usr/local/bin/npm&quot; &quot;install&quot;
    npm ERR! node v5.5.0
    npm ERR! npm  v3.5.3
    npm ERR! code E404
    npm ERR! 404 Not found : @company/config
    npm ERR! 404  &#39;@company/config&#39; is not in the npm registry.


Use of @ symbol in Node module names

I have this situation in which I would like to know what the status is of a promise. Below, the function `start` only calls `someTest` if it is not running anymore (Promise is not pending). The `start` function can be called many times, but if its called while the tests are still running, its not going to wait and returns just `false`

    class RunTest {
        start() {
             retVal = false;

             if (!this.promise) {
                 this.promise = this.someTest();
                 retVal = true;                
             }

             if ( /* if promise is resolved/rejected or not pending */ ) {
                 this.promise = this.someTest();
                 retVal = true;
             }

             return retVal;
        }

        someTest() {
            return new Promise((resolve, reject) =&gt; {
                // some tests go inhere
            });
        }
    }

I cannot find a way to simply check the status of a promise. Something like `this.promise.isPending` would be nice :) Any help would be appreciated!


How to check if a Promise is pending

I&#39;m trying to run a piece of JavaScript code written in a tutorial that looks like this:

**main.js**

    import Vue from &#39;Vue&#39;;
    import Alert from &#39;./components/Alert.vue&#39;;
    
    new Vue({
        el: &#39;body&#39;,
    
        components: { Alert }
    })

However, PhpStorm is giving the following error:  

&gt; Import declarations are not supported by current JavaScript version

How I can get a newer(?) JavaScript version in PhpStorm? Is that really the problem here?

Import not working with JavaScript in PhpStorm/Webstorm

I&#39;m still fairly new at React, but I&#39;ve been grinding along slowly and I&#39;ve encountered something I&#39;m stuck on. 

I am trying to build a &quot;timer&quot; component in React, and to be honest I don&#39;t know if I&#39;m doing this right (or efficiently). In my code below, I set the state to return an object ```{ currentCount: 10 }``` and have been toying with ```componentDidMount```, ```componentWillUnmount```, and ```render``` and I can only get the state to &quot;count down&quot; from 10 to 9. 

Two-part question: What am I getting wrong? And, is there a more efficient way of going about using setTimeout (rather than using ```componentDidMount``` &amp; ```componentWillUnmount```)?

Thank you in advance.

    import React from &#39;react&#39;;
    
    var Clock = React.createClass({
    
      getInitialState: function() {
        return { currentCount: 10 };
      },
    
      componentDidMount: function() {
        this.countdown = setInterval(this.timer, 1000);
      },
    
      componentWillUnmount: function() {
        clearInterval(this.countdown);
      },
    
      timer: function() {
        this.setState({ currentCount: 10 });
      },
    
      render: function() {
        var displayCount = this.state.currentCount--;
        return (
          &lt;section&gt;
            {displayCount}
          &lt;/section&gt;
        );
      }
    
    });
    
    module.exports = Clock;

setInterval in a React app

So I am using eslint as a linter for my react project and I would like it to check all of my `.js` files.

I am able to do this through the script:

    &quot;lint&quot;: &quot;eslint back/*.js &amp;&amp; eslint backTest/*.js &amp;&amp; eslint front/actions/*.js&quot;

how can I get it to examine every `.js` file recursively, something like:

    &quot;lint&quot;: &quot;eslint -r *.js&quot;

This would save me having to type out each file inidvidually

Thanks in advance for the help

How to configure package.json to run eslint script

I&#39;m rendering a link with react:

    render: -&gt;
      `&lt;a className=&quot;upvotes&quot; onClick={this.upvote}&gt;upvote&lt;/a&gt;`

Then, above I have the upvote function:

    upvote: -&gt;
      // do stuff (ajax)

Before link I had span in that place but I need to switch to link and here&#39;s the trouble - every time I click on `.upvotes` the page gets refreshed, what I&#39;ve tried so far:

***event.preventDefault() - not working.***

    upvote: (e) -&gt;
      e.preventDefault()
      // do stuff (ajax)

***event.stopPropagation() - not working.***

    upvote: (e) -&gt;
      e.stopPropagation()
      // do stuff (ajax)

***return false - not working.***

    upvote: (e) -&gt;
      // do stuff (ajax)
      return false

I&#39;ve also tried all of the above using jQuery in my index.html, but nothing seems to work. What should I do here and what I&#39;m doing wrong? I&#39;ve checked event.type and it&#39;s `click` so I guess I should be able to avoid redirect somehow?

Excuse me, I&#39;m a rookie when it comes to React.

Thank you!

React onClick and preventDefault() link refresh/redirect?

The story is, I should be able to put Bob, Sally and Jack into a box. I can also remove either from the box. When removed, no slot is left.

    people = [&quot;Bob&quot;, &quot;Sally&quot;, &quot;Jack&quot;]

I now need to remove, say, &quot;Bob&quot;. The new array would be:

    [&quot;Sally&quot;, &quot;Jack&quot;]

Here is my react component:

    ...
    
    getInitialState: function() {
      return{
        people: [],
      }
    },
    
    selectPeople(e){
      this.setState({people: this.state.people.concat([e.target.value])})
    },
    
    removePeople(e){
      var array = this.state.people;
      var index = array.indexOf(e.target.value); // Let&#39;s say it&#39;s Bob.
      delete array[index];
    },
    
    ...

Here I show you a minimal code as there is more to it (onClick etc). The key part is to delete, remove, destroy &quot;Bob&quot; from the array but `removePeople()` is not working when called. Any ideas? I was [looking at this][1] but I might be doing something wrong since I&#39;m using React.


  [1]: https://stackoverflow.com/questions/5767325/remove-a-particular-element-from-an-array-in-javascript

How to delete an item from state array?

Hi I want to know how to prompt a message on browser tab close.
I am using Reactjs.

    handleWindowClose(){
		alert(&quot;Alerted Browser Close&quot;);
	},
	componentDidMount: function() {
		window.addEventListener(&#39;onbeforeunload&#39;, this.handleWindowClose);
	},

	componentWillUnmount: function() {
		window.removeEventListener(&#39;onbeforeunload&#39;, this.handleWindowClose);
	}

this is what I have tried adding to my react component.Please guide me on how to proceed further.

Reactjs Browser Tab Close Event

Using [this boilerplate][1] as reference I created an [Electron][2] app. It uses webpack to bundle the scripts and express server to host it.

Webpack config is practically same as [this][3] and server [this][4].

Electron&#39;s script loads:

`mainWindow.loadURL(&#39;file://&#39; + __dirname + &#39;/app/index.html&#39;);`

And index.html loads the script hosted by the server:

`&lt;script src=&quot;http://localhost:3000/dist/bundle.js&quot;&gt;&lt;/script&gt;`

I run `electron index.js` to build the app and `node server` to start server which using webpack bundles the scripts.

It works fine, my React component App is mounted. But how I integrate react-router into this?

I implemented it the same way I would in a browser app. I get this error:

`[react-router] Location &quot;/Users/arjun/Documents/Github/electron-app/app/index.html&quot; did not match any routes`

It is taking file path as the route. Going through the boiler plate code did not help. What am I missing?

  [1]: https://github.com/chentsulin/electron-react-boilerplate
  [2]: http://electron.atom.io/
  [3]: https://github.com/chentsulin/electron-react-boilerplate/blob/master/webpack.config.development.js
  [4]: https://github.com/chentsulin/electron-react-boilerplate/blob/master/server.js

How to use React Router with Electron?

I have a web page with a search panel. Search panel has several input fields: id, size, ...

What I want is when user set search values (for example: id=123 and size=45) and press a search button:

 1. searchState in Redux reducer should be updated with new search values (id=123 and size=45)
 2. URL should be changed to &quot;http://mydomain/home?id=123&amp;size=45&quot;

And on the other hand if the user changes URL to http://mydomain/home?id=111&amp;size=22 then:

 1. searchState in reducer should be changed with new search values (id=111 and size=22)
 3. UI search panel inputs should be updated with new values (id=111 and size=22)

How to reach with goal? What router should I use (react-router, redux-router, react-router-redux ot other)?

How to sync Redux state and url query params

We have a list of lectures and chapters where the user can select and deselect them. The two lists are stored in a redux store.
Now we want to keep a representation of selected lecture slugs and chapter slugs in the hash tag of the url and any changes to the url should change the store too (two-way-syncing).

What would be the best solution using [react-router](https://github.com/reactjs/react-router) or even [react-router-redux](https://github.com/reactjs/react-router-redux)?

We couldn&#39;t really find some good examples where the react router is only used to maintain the hash tag of an url and also only updates one component.

How to sync Redux state and url hash tag params

I have an issue when navigating into another page, its position will remain like the page before. So it won&#39;t scroll to top automatically.
I&#39;ve also tried to use `window.scrollTo(0, 0)` on `onChange` router. I&#39;ve also used `scrollBehavior` to fix this issue but it didn&#39;t work. Any suggestions about this?

react-router scroll to top on every transition

I just checked out HOC&#39;s in React.  They are pretty cool.  However, doesn&#39;t simply wrapping a component achieve the same result?

### Higher Order Component
This simple HOC passes state as properties to the ComposedComponent

    const HOC = ComposedComponent =&gt; class extends React.Component {
       
        ... lifecycle, state, etc;...

        render() {
          return (&lt;ComposedComponent {...this.state} /&gt;);
        }      

    }

### Component Wrapping
This component passes state as properties to the child component

    class ParentComponent extends React.Component {
      
        ... lifecycle, state, etc;...
         
        render() {
          return (
            &lt;div&gt;
              {React.cloneElement(this.props.children, { ...this.state })}  
            &lt;/div&gt;
          );
        }      

    }


Although usage is slightly different between the two, they both seem to be equally as reusable.

Where is the real difference between HOC&#39;s and composing components via this.props.children?  Are there examples where you can only use one or the other? It is a better practice to use HOC&#39;s.  Are these just choices that you have where you get to pick your preferred flavor?

Content Type	Original Author	Original Content on Stackoverflow
Question	Ben Bieler	View Question on Stackoverflow
Solution 1 - Javascript	smcdrc	View Answer on Stackoverflow
Solution 2 - Javascript	Bojan Golubovic	View Answer on Stackoverflow
Solution 3 - Javascript	luanped	View Answer on Stackoverflow
Solution 4 - Javascript	MERLIN THOMAS	View Answer on Stackoverflow

What is the difference between hashHistory and browserHistory in react router?

Javascript Problem Overview

Javascript Solutions

Solution 1 - Javascript

Solution 2 - Javascript

Solution 3 - Javascript

Solution 4 - Javascript

How to add words to Atom's spell checker dictionary?

Refused to execute inline event handler because it violates CSP. (SANDBOX)

Attributions