Summary I am trying to set my FormData properly using javascript. I need to be able to upload jpg/png, but I might need to upload some other file types pdf/csv in the future using fetch. Expected I expect it to append the data to the form Error Working This snippet is working fine: Not working Question Does fetch support multiple
Tag: reactjs
Playing sound in React.js
This is the code that I am using to play the sound with url (this.url) in my react app. When I press the play button, it gives me an error Uncaught TypeError: Cannot read property ‘setState’ of undefined I am not sure why this is happpening since I don’t see any undefined states. A;; states have been declared. I am
Javascript create zip file
I am developing a website using react.js and admin-on-rest. One feature is allowing users to upload a pdf file. I get the file as type FILE and want to get the file from FILE, compress it to zip, and then make it to type FILE. So it should be FILE -> origin file -> zip file -> FILE from zip
Migrating create-react-app from javascript to typescript
I started a react project using create-react-app few months ago and I’m interesting in migrating the project from Javascript to Typescript. I saw that there is a way to create react app with typescript using the flag: But I didn’t find any explanation how can I migrate an existing JS project to TS. I need it to be done incrementally
Reactjs map works but forEach doesn’t
I’m struggling to understand the difference between forEach and map. In the following render function if the ‘forEach’ is replaced with ‘map’ it works. I don’t understand why it doesn’t work with the ‘forEach’. Both {item.id} and {item.text} are present with both methods. So, why are the props for ‘TodoItem’ not being set when using ‘forEach’ ? So if ‘forEach’
Warning Prop `href` did not match. using react server-side-rendering
I am using react-router-dom and I am guessing that this is causing the problem, but I have no clue where to even start looking or how to fix it. I also am getting errors like Warning: Did not expect server HTML to contain a <nav> in <div>. As I stated, I’m not really sure where to look so if you
How to reload current page in ReactJS?
How to reload current page in ReactJS? in case of javascript we can write window.location.reload(); How to do the same in Reactjs? I’m able to add new data by UI. But without refreshing, I’m not able to see the list. I want it so that whenever I’m adding some data, it refreshes by itself. Answer Since React eventually boils down
React treeview from JSON array
I am making a treeview from JSON using react. So far I have made a collapsible tree using this example data: But this is one object. I want to get JSON array of objects as input and generate treeview from that but I am unable to understand where to change the code. Here’s my render function: How can I change
Create React App with react-svg-loader without ejecting fails when trying to minify
I am using create-react-app to build my React application. I’ve added react-svg-loader and using it in this way: But when I am trying to run yarn build – process fails on minification step: Creating an optimized production build… Failed to compile. Failed to minify the code from this file: Read more here: http://bit .ly/2tRViJ9 Can I fix it somehow without
A component is changing an uncontrolled input of type text to be controlled error in ReactJS
Warning: A component is changing an uncontrolled input of type text to be controlled. Input elements should not switch from uncontrolled to controlled (or vice versa). Decide between using a controlled or uncontrolled input element for the lifetime of the component.* Following is my code: Answer The reason is, in state you defined: fields as a blank object, so during