Avoiding Wrapper Divs in ReactJs

Hi everyone,

Just a quick post on how you can avoid wrapper divs in ReactJs. It’s particularly useful when populating tables or creating parts of a larger component. Instead of the following:

return (
  <div>
    <td>Frogs</td>
    <td>Turtles</td>
  </div>
);

You can use fragments:

import React, { Fragment } from 'react'
...
return (
  <Fragment>
    <td>Frogs</td>
    <td>Turtles</td>
  </Fragment>
);

The fragment won’t polute the dom and mean that you don’t need to add any additional styling. Check out these links for more info:
https://reactjs.org/docs/fragments.html
https://stackoverflow.com/a/49375945/522859
https://reactjs.org/blog/2017/11/28/react-v16.2.0-fragment-support.html

Adding a Link to a Drawer – Material UI and ReactJS

Hi everyone,

I ran into a bit of an issue turning a menuitem into a link with Material UI and React-Router. The main problems being that underlines appeared and threw the spacing out.

To summarize, use the component attribute on the ListItem:

<List>
   <ListItem button component={Link} to="https://www.whatibroke.com">
        <ListItemText primary="WhatIBroke" />
   </ListItem>
</List>

The official docs cover it here: https://material-ui.com/api/list-item/

See the following stackoverflow post for more info: https://stackoverflow.com/a/50558139/522859

Where to Import Colors from in MaterialUI – ReactJS

Hey everyone,

I ran into the following error while trying to import colors in MaterialUI:

Module not found: Can’t resolve ‘material-ui/styles/colors’

It turns out that the path to colors changed in V1, so a lot of guides aren’t quite right. All you need to do is change it to the following:

/* import {grey, amber} from ‘material-ui/styles/colors’ Original */
import {grey, amber} from ‘material-ui/colors’ /* New */

Thanks to this Github post for the answer: https://github.com/mui-org/material-ui/issues/6446

Full Page Layout Example for Material UI – ReactJS

Hi everyone,

I’ve spent the last couple of days looking into MaterialUI. It seems really good however there are very few examples of a layout wireframe. After digging through Github I came across the following CodeSandbox:

There are a number of other themes and templates available (such as the amazing Material Dashboard) but they are all very in depth and not really suitable for a quick prototype or mock.

Thanks to Luke Peavey for posting the answer on StackOverflow. It definitely deserves a lot more views: https://stackoverflow.com/a/50312721/522859

Hopefully, this will be able to save someone else a bit of time!

Cheers,
Chris

Pass a Component as a Child Prop and Render it – ReactJs

Hi everyone,

A quick post on how to pass a component as a prop and then render it as a child.

const ChildComponent = () => <div>Child Component</div>;
 
const MainComponent = (props) => <div><div>Main component. Child appears below</div>{props.content}</div>;
 
class App extends React.Component {
 
  render () {                                        
    return (
      <div>          
          <MainComponent content={<ChildComponent />} />          
      </div>
    );
  }
}

An alternative to all of this that I wasn’t aware of is to to use “children”:

See the Pen ozqNOV by Dan Abramov (@gaearon) on CodePen.

Thanks to the following stackoverflow post for the info: https://stackoverflow.com/a/41499555/522859

Remote Desktop: An authentication error has occurred. – This could be due to CredSSP encryption oracle remediation.

Hi everyone,

I ran into an auth issue with remote desktop today:

An authentication error has occurred.
The function requested is not supported.
Remote computer: XXXX

This could be due to CredSSP encryption oracle remediation.
For more information, see hhtps://go.microsoft.com/fwlink/?linkid=866660

The solution is to add the May 2018 Windows Security Update on both the remote and local machines. If that’s not possible a registry entry can be added to the local machine to circumvent the issue. This can be done by running the following command in a command prompt as administrator:

REG ADD HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\System\CredSSP\Parameters\ /v AllowEncryptionOracle /t REG_DWORD /d 2

You can also add the entry manually via regedit.

The cause is actually because of a security update in windows. If either the remote or local machine has the update and the other does not the error is triggered. There’s more info available on the following page: https://github.com/stascorp/rdpwrap/issues/480

Web API 2 – ExceptionMessage=No MediaTypeFormatter is available to read an object of type ‘HttpPostedFileBase’ from content with media type ‘multipart/form-data’.

Hi everyone,

I ran into the following error while trying to get image uploads working with Web API 2:

ExceptionMessage=No MediaTypeFormatter is available to read an object of type ‘HttpPostedFileBase’ from content with media type ‘multipart/form-data’.

I had been trying to copy the following from an mvc controller in another project:

public IHttpActionResult Upload(HttpPostedFileBase file, Models.Image.ImageAssociationType associationType, int associationId)

The fix was to use the following instead:

public IHttpActionResult Upload(Models.Image.ImageAssociationType associationType, int associationId)
{
var file = HttpContext.Current.Request.Files.Count > 0 ? HttpContext.Current.Request.Files[0] : null;

Thanks to this stackoverflow post for the info: https://stackoverflow.com/a/28370156/522859

DbSet does not contain a definition for ‘FromSQL’ and no extension method ‘FromSql’ accepting an argument of type ‘DbSet‘ could be found.

Hi everyone,

I ran into the following error while attempting to use a custom query with EntityFramework:

DbSet does not contain a definition for ‘FromSQL’ and no extension method ‘FromSql’ accepting an argument of type ‘DbSet‘ could be found.

This one’s pretty straight forward:

// Install the following package via nuget
Install-package Microsoft.EntityFrameworkCore.Relational

//Add the following namespace to your file
using Microsoft.EntityFrameworkCore;

Hopefully that’ll solve it for you, but if not there’s a lot a more information in these posts:
https://stackoverflow.com/a/38919326/522859
https://github.com/npgsql/Npgsql.EntityFrameworkCore.PostgreSQL/issues/146

Module not found: Can’t resolve ‘babel-polyfill’ in ‘C:\Users\source\repos\frontend\src

Hi everyone,

I was looking into asynchronous requests with redux tonight and hit the following error:

Module not found: Can’t resolve ‘babel-polyfill’ in ‘C:\Users\source\repos\frontend\src

This is used to provide a promise polyfill for a fetch package mentioned in the tutorial. In order to fix it, just run the following:

npm install babel-polyfill

Thanks to the following post for the solution: https://stackoverflow.com/a/33568284/522859

Module not found: Can’t resolve ‘redux’ in ‘C:\Users\FrontEndSrc\frontend\node_modules\react-redux\es\connect’

Hi everyone,

Another quick one. I’d installed react-redux but was running into the following error:

Failed to compile.

./node_modules/react-redux/es/connect/mapDispatchToProps.js
Module not found: Can’t resolve ‘redux’ in ‘C:\Users\source\repos\FrontEndSrc\frontend\node_modules\react-redux\es\connect’

Fairly easy fix, you need react as well as react-redux:

npm install –save redux

Once that’s done, it should all be working!

Cheers,
Chris