Change ` ng-disabled=&quot;!contractTypeValid&quot;` to ` [disabled]=&quot;!contractTypeValid&quot;`

I tried use `[disabled]=&quot;!editmode&quot;` but it not work in my case.

This is my solution `[disabled]=&quot;!editmode ? &#39;disabled&#39;: null&quot;` , I share for whom concern.
    
    &lt;button [disabled]=&quot;!editmode ? &#39;disabled&#39;: null&quot; 
        (click)=&#39;loadChart()&#39;&gt;
        		&lt;div class=&quot;btn-primary&quot;&gt;Load Chart&lt;/div&gt;
        &lt;/button&gt;

Stackbliz https://stackblitz.com/edit/angular-af55ep

I&#39;m using Androids built in day/night mode functionality and I&#39;d like to add an option to my app for `AppCompatDelegate.MODE_NIGHT_AUTO`

I&#39;m having a problem though because my app requires certain things to be colored programmatically, and I can&#39;t figure out how to check if the app considers itself in night or day mode.  Without that, I can&#39;t set a flag to choose the right colors.

Calling `AppCompatDelegate.getDefaultNightMode()` just returns AppCompatDelegate.MODE_NIGHT_AUTO which is useless.

I don&#39;t see anything else that would tell me, but there must be something?




Android - How to detect if night mode is on when using AppCompatDelegate.MODE_NIGHT_AUTO

This question comes from the Material2 Github [repo][1]. 

I still have problems to style a Material component that is wrapped in a custom component.

I have a `&lt;logo&gt;` component that contains `&lt;md-icon svgIcon=&quot;logo&quot;&gt;&lt;/md-icon&gt;`

Adding: 

    :host { 
       .mat-icon {
        width: 100px;
        height: 100px;
        font-size: 56px;
      }
    }

Will not apply to the Material component inside my custom component.


  [1]: https://github.com/angular/material2/issues/4422#issuecomment-300309224

How to change mat-icon size in Material

I want if the input &#39;Contract type&#39; is empty, the button &#39;Save&#39; is not clickable

Save button: 

    &lt;div class=&quot;col-md-4&quot;&gt;
            &lt;cic-textbox [control]=&quot;formGroup.get(&#39;contractType&#39;)&quot;&gt;&lt;/cic-textbox&gt;
          &lt;/div&gt;

ALL Buttons:

     &lt;div class=&quot;cic-header-actions pull-left&quot; *ngIf=&quot;actions &amp;&amp; actions.length &gt; 
     0&quot;&gt;
          &lt;button class=&quot;btn btn-{{action.style}} m-l-xs&quot; *ngFor=&quot;let action of actions&quot; ng-disabled=&quot;!contractTypeValid&quot; (click)=&quot;execute(action)&quot;&gt;
              &lt;cic-icon [icon]=&quot;action.icon&quot;&gt;&lt;/cic-icon&gt;
              {{action.text }}
            &lt;/button&gt;
        &lt;/div&gt;

Definition contractType: 

     let contractType: DataDictionaryPropertyExtended = {
                Binding: &#39;VART:BEZEICHNUNG&#39;,
                Label: &#39;Vertragsart&#39;,
                LabelCols: 4,
                ContentCols: 8,
                IsDisabled: this.isDisabled,
                ValidationProperties: [
                    &lt;ValidationProperty&gt;{
                        Type: ValidationType.IsNotEmpty,
                        ErrorMessage: &#39;Vertragsart darf nicht leer sein.&#39;,
                    }
                ]
            };


BUTTON SAVE GREEN:

[![enter image description here][1]][1]

  [1]: https://i.stack.imgur.com/QE5M2.jpg

Disable Button in Angular 2

I want if the input 'Contract type' is empty, the button 'Save' is not clickable
Save button:
<pre><code class="hljs language-php-template">&#x3C;div class="col-md-4">
 &#x3C;cic-textbox [control]="formGroup.get('contractType')">&#x3C;/cic-textbox>
 &#x3C;/div>
</code></pre>
ALL Buttons:
<pre><code class="hljs language-php-template"> &#x3C;div class="cic-header-actions pull-left" *ngIf="actions &#x26;&#x26; actions.length > 
 0">
 &#x3C;button class="btn btn-{{action.style}} m-l-xs" *ngFor="let action of actions" ng-disabled="!contractTypeValid" (click)="execute(action)">
 &#x3C;cic-icon [icon]="action.icon">&#x3C;/cic-icon>
 {{action.text }}
 &#x3C;/button>
 &#x3C;/div>
</code></pre>
Definition contractType:
<pre><code class="hljs language-yaml"> let contractType: DataDictionaryPropertyExtended = {
 Binding: 'VART:BEZEICHNUNG',
 Label: 'Vertragsart',
 LabelCols: 4,
 ContentCols: 8,
 IsDisabled: this.isDisabled,
 ValidationProperties: [
 &#x3C;ValidationProperty>{
 Type: ValidationType.IsNotEmpty,
 ErrorMessage: 'Vertragsart darf nicht leer sein.',
 }
 ]
 };
</code></pre>
BUTTON SAVE GREEN:
<a href="https://i.stack.imgur.com/QE5M2.jpg" target="_blank" rel="noopener noreferrer"><img src="https://i.stack.imgur.com/QE5M2.jpg" alt="enter image description here"></a>

I&#39;m doing some basic asynchronous operations using `async/await` in TypeScript but TSLint is throwing mysterious error messages for these two functions below. Has anyone encountered these errors before? On the error output the governing rule is not mentioned, so I don&#39;t understand what&#39;s causing these. Any ideas would be greatly appreciated.

The main request:

    import * as rp from &#39;request-promise&#39;
    
    export function getRequest(address: rp.Options): rp.RequestPromise {
      return rp(address)
    }


Exported async function:  

    export async function getStatus(message: Message) {
      try {
        const res = await getRequest(address)
        if (res.ready) {
          message.reply(&#39;...&#39;)
        } else {
          message.reply(&#39;...&#39;)
        }
      } catch (err) {
        message.reply(err)
      }
    }

This gets: `Promises must be handled appropriately`and `await of non-Promise` for line #3.

The simple function that uses this export is:

    client.on(&#39;message&#39;, message =&gt; {
      if (message.content === &#39;green&#39;) {
        getStatus(message)
      }
    })

This also gets `Promises must be handled appropriately`.

Additional information:

Even though the error message doesn&#39;t mention it, this seems to be the governing rule for `Promises must be handled appropriately`:
https://palantir.github.io/tslint/rules/no-floating-promises/

And this Issue mentions `await of non-Promise`:
https://github.com/palantir/tslint/issues/2661


What could this be about? [TsLint Error: &quot;Promises must be handled appropriately&quot;]

Here is my current template:

    &lt;a-droppable v-for=&quot;n in curSize&quot; :key=&quot;n - 1&quot; :style=&quot;{width: `${99.99 / rowLenMap[orderList[n - 1]]}%`, order: orderList[n - 1]}&quot;&gt;
      &lt;a-draggable :class=&quot;{thin: rowLenMap[orderList[n - 1]] &gt; 10}&quot;&gt;
        &lt;some-inner-element&gt;{{rowLenMap[orderList[n - 1]]}}&lt;/some-inner-element&gt;
      &lt;/a-draggable&gt;
    &lt;/a-droppable&gt;

The problem is that i have to write `rowLenMap[orderList[n - 1]]` multiple times, and i&#39;m afraid vue.js engine will also calculate it multiple times.

What i want is something like this:

    &lt;a-droppable v-for=&quot;n in curSize&quot; :key=&quot;n - 1&quot; v-define=&quot;rowLenMap[orderList[n - 1]] as rowLen&quot; :style=&quot;{width: `${99.99 / rowLen}%`, order: orderList[n - 1]}&quot;&gt;
      &lt;a-draggable :class=&quot;{thin: rowLen &gt; 10}&quot;&gt;
        &lt;some-inner-element&gt;{{rowLen}}&lt;/some-inner-element&gt;
      &lt;/a-draggable&gt;
    &lt;/a-droppable&gt;

I think it&#39;s not difficult to implement technically because it can be clumsily solved by using something like `v-for=&quot;rowLen in [rowLenMap[orderList[n - 1]]]&quot;`. So is there any concise and official solution?

How to define a temporary variable in Vue.js template

In my app i have something like:

    this._personService.getName(id)
          .concat(this._documentService.getDocument())
          .subscribe((response) =&gt; {
                      console.log(response)
                      this.showForm()
           });
   
     //Output: 
     // [getnameResult]
     // [getDocumentResult]

     // I want:
     // [getnameResult][getDocumentResult]


Then i get two separated results, first of the `_personService` and then the `_documentService`. How can I wait for both results before call `this.showForm()` to finish an then manipulate the results of each one.


How to &#39;wait&#39; for two observables in RxJS

I have a **Dashboard** with rotating slides, each of which has a corresponding tab in **Bldgs**. Both `Dashboard.js` and `Bldgs.js` are children to my `App.js`.

When a user clicks on a specific slide `A` in `Dashboard.js`, `Dashboard` needs to tell `App.js` so that `App` can tell `Bldgs.js` to have tab `A` displayed when it routes to `Bldgs`.

I *believe* that I am passing the correct index value from `Dashboard` up to `App` and down to `Bldgs`. However, an error is being thrown in my `App.js` file stating:

`Uncaught TypeError: Cannot read property &#39;push&#39; of undefined`

My code was working fine before I started passing my `handleClick()` function to my `Dashboard` component.

**Index.js**

    import React from &#39;react&#39;;
    import ReactDOM from &#39;react-dom&#39;;
    import App from &#39;./App&#39;;
    import &#39;./index.css&#39;;
    import injectTapEventPlugin from &#39;react-tap-event-plugin&#39;;
    import MuiThemeProvider from &#39;material-ui/styles/MuiThemeProvider&#39;;
    import { BrowserRouter as Router } from &#39;react-router-dom&#39;;
    import { hashHistory } from &#39;react-router&#39;;
    
    // Needed for onTouchTap
    // http://stackoverflow.com/a/34015469/988941
    injectTapEventPlugin();

    ReactDOM.render(
      &lt;MuiThemeProvider&gt;
        &lt;Router history={hashHistory}&gt;
          &lt;App /&gt;
        &lt;/Router&gt;
      &lt;/MuiThemeProvider&gt;,
      document.getElementById(&#39;root&#39;)
    );

**App.js**

    import React from &#39;react&#39;;
    import { Route } from &#39;react-router-dom&#39;;
    import Dashboard from &#39;./Dashboard&#39;;
    import Bldgs from &#39;./Bldgs&#39;;
    
    var selectedTab;
    
    class App extends React.Component {
      constructor(props) {
        super(props);
        this.handleClick = this.handleClick.bind(this);
        selectedTab = 0;
      }
    
      handleClick(value) {
        selectedTab = value;
        // console.log(selectedTab);
        this.props.history.push(&#39;/Bldgs&#39;);
        // console.log(this.props);
      }
    
      render() {
        var _this = this;
    
        return (
          &lt;div&gt;
            &lt;Route exact path=&quot;/&quot; render={(props) =&gt; &lt;Dashboard {...props} handleClick={_this.handleClick} /&gt;} /&gt;
            &lt;Route path=&quot;/Bldgs&quot; component={Bldgs} curTab={selectedTab} /&gt;
          &lt;/div&gt;
        );
      }
    }
    
    export default App;

**Dashboard.js**

    import React, { Component } from &#39;react&#39;;
    import &#39;./Dashboard.css&#39;;
    import { AutoRotatingCarousel, Slide } from &#39;material-auto-rotating-carousel&#39;;
    ...

    var curIndex;

    class Dashboard extends Component {
      constructor(props) {
        super(props);
        this.handleEnter = this.handleEnter.bind(this);
        this.handleChange = this.handleChange.bind(this);
        curIndex = 0;
      }
    
      handleEnter(e) {
        // console.log(curIndex);
        this.props.handleClick(curIndex);
      }
    
      handleChange(value) {
        // console.log(value);
        curIndex = value;
      }
    
    ...
    }
    
    export default Dashboard;

**Bldgs.js**

    ...
    var curTab;

    class Bldgs extends Component {
      constructor(props) {
        super(props);
        this.handleChange = this.handleChange.bind(this);
        this.goHome = this.goHome.bind(this);
        curTab = 0;
      }

      handleChange(value) {
        this.setState({&#39;selectedTab&#39;: value});
        console.log(this.state);
      }

      goHome(e) {
        this.props.history.push(&#39;/&#39;);
      }
    
    ...
    }

    export default Bldgs;

Uncaught TypeError: Cannot read property &#39;push&#39; of undefined (React-Router-Dom)

I&#39;m using the JavaScript SDK for AWS Cognito, and there are a couple of custom attributes that I just can&#39;t seem to save to and can&#39;t see why.

The problem attributes are mutable string fields as follows:

    custom: role
    custom: recruitingrole
    custom: title

Other custom fields in the same request seem to update OK.  Specifically, these ones seem to work:

    custom:division
    custom:linkedin
    custom:location
    custom:bio

When I submit via the SDK, this is returned:

{&quot;__type&quot;:&quot;NotAuthorizedException&quot;,&quot;message&quot;:&quot;A client attempted to write unauthorized attribute&quot;}

Here is the data that is sent, as show in the Chrome developer console network output:

    {
    	&quot;AccessToken&quot;: &quot;&quot;,
    	&quot;UserAttributes&quot;: [{
    		&quot;Name&quot;: &quot;name&quot;,
    		&quot;Value&quot;: &quot;Steve Austin&quot;
    	}, {
    		&quot;Name&quot;: &quot;custom:company&quot;,
    		&quot;Value&quot;: &quot;OSI&quot;
    	}, {
    		&quot;Name&quot;: &quot;custom:division&quot;,
    		&quot;Value&quot;: &quot;Bionics&quot;
    	}, {
    		&quot;Name&quot;: &quot;custom:recruitingrole&quot;,
    		&quot;Value&quot;: &quot;other&quot;
    	}, {
    		&quot;Name&quot;: &quot;custom:linkedin&quot;,
    		&quot;Value&quot;: &quot;http://www.linkedin.com&quot;
    	}, {
    		&quot;Name&quot;: &quot;custom:location&quot;,
    		&quot;Value&quot;: &quot;Mexico City, Mexico City, Mexico&quot;
    	}, {
    		&quot;Name&quot;: &quot;custom:bio&quot;,
    		&quot;Value&quot;: &quot;A man barely alive.&quot;
    	}]
    }

Can anyone suggest why I can&#39;t save to these attributes?

thanks

Amazon Cognito &quot;A client attempted to write unauthorized attribute&quot;

How can I reload the current page on Angular 2?

if iam in page 2 (pagination) and refresh the page it will show page 1(URL pageload)
but i want i refresh the page 2 and it will appear in page 2

How to reload page the page with pagination in Angular 2?

I really struggle with creating global variables in my Angular 2 application. 

So I have my file called **globals.ts**, which looks like this:

    import { Injectable } from &quot;@angular/core&quot;;


    @Injectable()
    export class Globals {

      var role = &#39;test&#39;;

    }

And I want to use the variable role in my HTML view of my component like this:

    {{ role }} 

I already added the globals.ts file to my **app.module.ts** in the following way:

    providers: [
      Globals
    ],

No matter what I did on this file, it just didn&#39;t work. What I don&#39;t want to do is to have to import the globals.ts file in every component manually, which is why I want to use the providers feature.


Angular 4/5/6 Global Variables

What is the difference between `generic Type(T)` vs `any` in typescript?
---------------------------------------------------------------------

Function 1
----------

    function identity(arg: any): any {
        return arg;
    }

Function 2 
-----------

    function identity&lt;T&gt;(arg: T): T {
        return arg;
    }
    
Function 3
--------------
    function identity&lt;T&gt;(arg: T[]): T[] {
        return arg;
    }


----------


&gt;Function 1 &amp; 3 is accepted if we passing any kind of ` data type`, But the function 2 does not accept if we pass an `array`. **generic type is accepting all kind of data type on compile time**. but here why it does not accept? 

***Also which function is good for better performance ( function 1 or function 3)?***

What are the difference between generic Type(T) vs any in typescript

So I was trying to build and deploy my Angular 4 app for production on both Firebase and Heroku, but I have come across the error as follows:

&gt; ERROR in /Users/.../... (57,49):  Property &#39;firebase&#39; does not exist
&gt; on type &#39;{ production: boolean; }&#39;.

It occurs when I run `ng build --prod`, and my deployment servers are working perfectly fine. Here is my **app.module.ts** file, for reference:

```typescript
import { BrowserModule } from &#39;@angular/platform-browser&#39;;
import { NgModule } from &#39;@angular/core&#39;;
import { FormsModule } from &#39;@angular/forms&#39;;
import { AngularFireModule } from &#39;angularfire2&#39;;
import { AngularFireDatabaseModule } from &#39;angularfire2/database&#39;;
import { Ng2ScrollimateModule } from &#39;ng2-scrollimate&#39;;
import { Ng2PageScrollModule } from &#39;ng2-page-scroll&#39;;

import { HttpModule } from &#39;@angular/http&#39;;
import { trigger, state, style, animate, transition, keyframes } from &#39;@angular/animations&#39;;
import { BrowserAnimationsModule } from &#39;@angular/platform-browser/animations&#39;;
import { environment } from &#39;../environments/environment&#39;;

import { AppComponent } from &#39;./app.component&#39;;

import { LogoComponent } from &#39;./logo/logo.component&#39;;
import { InfoComponent } from &#39;./info/info.component&#39;;
import { AboutComponent } from &#39;./about/about.component&#39;;
import { DividerComponent } from &#39;./divider/divider.component&#39;;
import { ProficienciesComponent } from &#39;./proficiencies/proficiencies.component&#39;;
import { ProficiencyComponent } from &#39;./proficiency/proficiency.component&#39;;
import { PortfolioComponent } from &#39;./portfolio/portfolio.component&#39;;
import { ProjectComponent } from &#39;./project/project.component&#39;;
import { ResumeComponent } from &#39;./resume/resume.component&#39;;
import { FooterComponent } from &#39;./footer/footer.component&#39;;
import { ContactComponent } from &#39;./contact/contact.component&#39;;
import { LoadingComponent } from &#39;./loading/loading.component&#39;;

@NgModule({
  declarations: [
    AppComponent,
    LogoComponent,
    InfoComponent,
    AboutComponent,
    DividerComponent,
    ProficienciesComponent,
    ProficiencyComponent,
    PortfolioComponent,
    ProjectComponent,
    ResumeComponent,
    FooterComponent,
    ContactComponent,
    LoadingComponent,
  ],
  imports: [
    BrowserModule,
    FormsModule,
    HttpModule,
    BrowserAnimationsModule,
    AngularFireModule.initializeApp(environment.firebase),
    AngularFireDatabaseModule,
    Ng2ScrollimateModule,
    Ng2PageScrollModule.forRoot(),
  ],
  providers: [],
  bootstrap: [AppComponent],
})
export class AppModule {}
```

**environment.prod.ts**

```typescript
export const environment = {
  production: true
};
```

**environment.ts**

```typescript
export const environment = {
  production: true,
  firebase: {
    apiKey: &#39;...&#39;,
    authDomain: &#39;project.firebaseapp.com&#39;,
    databaseURL: &#39;https://project.firebaseio.com&#39;,
    projectId: &#39;project&#39;,
    storageBucket: &#39;project.appspot.com&#39;,
    messagingSenderId: &#39;...&#39;,
  },
};
```
After scouring StackOverflow and GitHub for possible solutions, there seem to be no developers who have encountered this exact error and published their findings, so I was wondering whether anyone knows how to go about solving this issue. Thanks so much in advance!

Property &#39;firebase&#39; does not exist on type { production: boolean; }

Been developing a flutter app and dynamicly building some containers from some Firebase data. 
I wanted to know if there is a way to get a onTap method for containers (or any widget which is not a button ?

Here is a code sample :

      child: new Container(

        //INSERT ONTAP OR ONPRESSED METHOD HERE

        margin: const EdgeInsets.symmetric(vertical: 10.0),
        child: new Row(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: &lt;Widget&gt;[
            new Container(
              margin: const EdgeInsets.only(right: 16.0),
              child: new GoogleUserCircleAvatar(snapshot.value[&#39;images&#39;][0]),
            ),
            new Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children : [
                new Container(
                  padding: const EdgeInsets.only(bottom: 8.0),
                  child: new Text(&quot;${snapshot.value[&#39;name&#39;]}&quot;,
                    style: new TextStyle(
                      fontWeight: FontWeight.bold,
                    ),
                  ),
                 ),
                new Text(&quot;${snapshot.value[&#39;description&#39;]}&quot;,
                  style: new TextStyle(
                    color: Colors.grey[500],
                  ),
                ),
              ]
            )
          ],
        ),

Flutter onTap method for Containers

Can I wrap or enclose a `router-link` tag in a `button` tag? 

When I press the button, I want it to route me to the desired page. 

Enclosing a router-link tag in a button in vuejs

I&#39;m just starting to get the hang of Flutter, but I&#39;m having trouble figuring out how to set the enabled state of a button.

From the docs, it says to set `onPressed` to null to disable a button, and give it a value to enable it. This is fine if the button continues to be in the same state for the lifecycle.

I get the impression I need to create a custom Stateful widget that will allow me to update the button&#39;s enabled state (or onPressed callback) somehow.

So my question is how would I do that? This seems like a pretty straightforward requirement, but I can&#39;t find anything in the docs on how to do it.

Thanks.

How do I disable a Button in Flutter?

I am just creating a form in Flutter. I am not able to set the top margin for the button.

    class _MyHomePageState extends State&lt;MyHomePage&gt; {
      
    String firstname; 
    String lastname;
    final scaffoldKey = new GlobalKey&lt;ScaffoldState&gt;();
    final formKey = new GlobalKey&lt;FormState&gt;();
    
    
        @override
      Widget build(BuildContext context) {
        return new Scaffold(
          key: scaffoldKey,
          appBar: new AppBar(
            title: new Text(&#39;Validating forms&#39;),
          ),
          body: new Padding(
            padding: const EdgeInsets.all(16.0),
            child: new Form(
              key: formKey,
              child: new Column(
                children: [
                  new TextFormField(
                    decoration: new InputDecoration(labelText: &#39;First Name&#39;),
                    validator: (val) =&gt;
                        val.length == 0 ?&quot;Enter FirstName&quot; : null,
                    onSaved: (val) =&gt; firstname = val,
                  ),
                  new TextFormField(
                    decoration: new InputDecoration(labelText: &#39;Password&#39;),
                    validator: (val) =&gt;
                        val.length ==0 ? &#39;Enter LastName&#39; : null,
                    onSaved: (val) =&gt; lastname = val,
                    obscureText: true,
                  ),
                  new RaisedButton(
                    onPressed: _submit,
                    child: new Text(&#39;Login&#39;),
                  ),
                ],
              ),
            ),
          ),
        );
      }



How to set margin for a Button in Flutter

I want to have a row of IconButtons, all next to each other, but there seems to be pretty big padding between the actual icon, and the IconButton limits. I&#39;ve already set the padding on the button to 0.

This is my component, pretty straightforward:


    class ActionButtons extends StatelessWidget {
      @override
        Widget build(BuildContext context) {
          return Container(
            color: Colors.lightBlue,
            margin: const EdgeInsets.all(0.0),
            padding: const EdgeInsets.all(0.0),
            child: Row(
              mainAxisAlignment: MainAxisAlignment.start,
              children: &lt;Widget&gt;[
                IconButton(
                  icon: new Icon(ScanrIcons.reg),
                  alignment: Alignment.center,
                  padding: new EdgeInsets.all(0.0),
                  onPressed: () {},
                ),
                IconButton(
                  icon: new Icon(Icons.volume_up),
                  alignment: Alignment.center,
                  padding: new EdgeInsets.all(0.0),
                  onPressed: () {},
                )
              ],
            ),
          );
        }
    }


[![enter image description here][1]][1]

I want to get rid of most of the light blue space, have my icons start earlier on the left, and closer to each other, but I can&#39;t find the way to resize the IconButton itself.

I&#39;m almost sure this space is taken by the button itself, &#39;cause if I change their alignments to `centerRight` and `centerLeft` they look like this:

[![enter image description here][2]][2]

Making the actual icons smaller doesn&#39;t help either, the button is still big:

[![enter image description here][3]][3]

thanks for the help


  [1]: https://i.stack.imgur.com/aQwXv.png
  [2]: https://i.stack.imgur.com/cT4s7.png
  [3]: https://i.stack.imgur.com/nhKjv.png

How do I remove Flutter IconButton big padding?

I&#39;m presented with a rather silly problem. I am in the process of creating my first React application and I have encountered a little issue, where I am not able to clear my input value, after I submit a form. A tried googling this problem, found some similar threads here, but I was not able to resolve this. I do NOT want to change the state of my component/application, just to change the value of the input to an empty string. I tried clearing the value of the input in my `onHandleSubmit()` function, but I got an error:

&gt; &quot;Cannot set property &#39;value&#39; of undefined&quot;.

My SearchBar Component:

    import React, { Component } from &quot;react&quot;;
    
    class SearchBar extends Component {
      constructor(props) {
        super(props);
    
        this.state = {
          city: &quot;&quot;
        };
    
        this.onHandleChange = this.onHandleChange.bind(this);
        this.onHandleSubmit = this.onHandleSubmit.bind(this);
      }
    
      render() {
        return (
          &lt;form&gt;
            &lt;input
              id=&quot;mainInput&quot;
              onChange={this.onHandleChange}
              placeholder=&quot;Get current weather...&quot;
              value={this.state.city}
              type=&quot;text&quot;
            /&gt;
            &lt;button onClick={this.onHandleSubmit} type=&quot;submit&quot;&gt;
              Search!
            &lt;/button&gt;
          &lt;/form&gt;
        );
      }
    
      onHandleChange(e) {
        this.setState({
          city: e.target.value
        });
      }
    
      onHandleSubmit(e) {
        e.preventDefault();
        const city = this.state.city;
        this.props.onSearchTermChange(city);
        this.mainInput.value = &quot;&quot;;
      }
    }
    
    export default SearchBar;



React - clearing an input value after form submit

I want to convert JSON string into an array in bash.
The JSON string is passed to the bash script as an argument (it doesn&#39;t exist in a file).

Is there a way of achieving it without using some temp files?

Similarly to this:

    script.sh

    #! /bin/bash
    json_data=&#39;{&quot;key&quot;:&quot;value&quot;}&#39;
    jq &#39;.key&#39; $json_data

    jq: error: Could not open file {key:value}: No such file or directory

Can I pass a string variable to jq not the file?

I would like to know how to get the value from an input on angular 4.
I looked over the documentation on angular and the example with the key event doesn&#39;t work very well for me and I can&#39;t find a proper example how to do this so please help me out

The problem:
I try to read the input&#39;s value and after submiting the value to another component that will add the value to a select tag(e.g. send the name of the person to a list for a select tag)

  [![My code][1]][1]

  [1]: https://i.stack.imgur.com/okEPd.png

Angular 4 - get input value

I use material ui v0.20.0 and I have to prohibit saving the password for a user with TextField. I added props to TextField autocomplete=&#39;nope&#39; cause not all the browsers understand autocomplete=&#39;off&#39;. It seems that the last version of Chrome 63 does not accept it. Sometimes it does not work and sometimes it does. I can not get why it works so hectic. When chrome asks to save password and I save it, and after that I want to edit input I still have this : [![enter image description here][1]][1] 

      &lt;TextField
             name=&#39;userName&#39;
             floatingLabelText={&lt;FormattedMessage id=&#39;users.username&#39; /&gt;}
             value={name || &#39;&#39;}
             onChange={(e, name) =&gt; this.changeUser({name})}
             // autoComplete=&#39;new-password&#39;
    
        /&gt; 

        &lt;TextField
            name=&#39;password&#39;
            floatingLabelText={&lt;FormattedMessage id=&#39;users.passwords.new&#39; /&gt;}
            type=&#39;password&#39;
            value={password || &#39;&#39;}
            onChange={(e, password) =&gt; this.changeUser({password})}
            autoComplete=&#39;new-password&#39;
       /&gt;


Looks like it works in Firefox(v57.0.4)

By default TextField does not have autoComplete=&#39;off&#39;
[![enter image description here][2]][2]


  [1]: https://i.stack.imgur.com/9NZgs.png
  [2]: https://i.stack.imgur.com/5edIQ.png

material-ui TextField disable Browser autoComplete

Coderbyte is an online coding challenge site (I found it just 2 minutes ago).

[The first C++ challenge][1] you are greeted with has a C++ skeleton you need to modify:

&gt;     #include &lt;iostream&gt;
&gt;     #include &lt;string&gt;
&gt;     using namespace std;
&gt;
&gt;     int FirstFactorial(int num) {
&gt;
&gt;       // Code goes here
&gt;       return num;
&gt;
&gt;     }
&gt;
&gt;     int main() {
&gt;
&gt;       // Keep this function call here
&gt;       cout &lt;&lt; FirstFactorial(gets(stdin));
&gt;       return 0;
&gt;
&gt;     }

If you are little familiar with C++ the first thing&lt;sup&gt;*&lt;/sup&gt; that pops in your eyes is:

```
int FirstFactorial(int num);
cout &lt;&lt; FirstFactorial(gets(stdin));
```

So, ok, the code calls `gets` which is deprecated since C++11 and removed since C++14 which is bad in itself. 

But then I realize: `gets` is of type `char*(char*)`. So it shouldn&#39;t accept a `FILE*` parameter and the result shouldn&#39;t be usable in the place of an `int` parameter, but ... not only it compiles without any warnings or errors, but it runs and actually passes the correct input value to `FirstFactorial`.

Outside of this particular site, the code doesn&#39;t compile (as expected), so what is going on here?

---

&lt;sup&gt;*Actually the first one is `using namespace std` but that is irrelevant to my issue here.&lt;/sup&gt;

  [1]: https://www.coderbyte.com/editor/guest:First%20Factorial:Cpp



What is going on with &#39;gets(stdin)&#39; on the site coderbyte?

I am working on an Angular project. I&#39;m struggling with refresh action in a component. &lt;br&gt;&lt;br&gt;
I would like to refresh the router&#39;s components on button click.
I have refresh button when I click on it the component/router need to be refresh.&lt;br&gt;&lt;br&gt;
I tried `window.location.reload()` and `location.reload()` these two are not suitable for my need. Please help if anyone aware of it.
 

How to Refresh a Component in Angular

I&#39;m using react-select and I&#39;m customizing it,I didn&#39;t found an option to do this. Is there some workaround I can use to keep dropdown open when I&#39;m styling it?

react-select: how to keep dropdown open when styling in inspector?

So I&#39;ve created a simple wrapper component with template like:

    &lt;wrapper&gt;
       &lt;b-table v-bind=&quot;$attrs&quot; v-on=&quot;$listeners&quot;&gt;&lt;/b-table&gt;
    &lt;/wrapper&gt;

using `$attrs` and `$listeners` to pass down props and events.   
Works fine, but how can the wrapper proxy the `&lt;b-table&gt;` named slots to the child?

Vue - how to pass down slots inside wrapper component?

I have the following simple short-circuit statement that should show either a component or nothing:

`{profileTypesLoading &amp;&amp; &lt;GeneralLoader /&gt;}`

If the statement is false, it renders a `0` instead of nothing.

I have done a `console.log(profileTypesLoading)` just to see quickly what the status of the `profileTypesLoading` property is and it&#39;s either 1 or 0 as expected.  0 should be false... causing nothing to render.  Right?

Any idea why this would happen?

Content Type	Original Author	Original Content on Stackoverflow
Question	user7325116	View Question on Stackoverflow
Solution 1 - Javascript	Robin Dijkhof	View Answer on Stackoverflow
Solution 2 - Javascript	Hien Nguyen	View Answer on Stackoverflow

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