How to insert properties and functions inside ref?

How can I insert properties and functions inside a ref? Like this example: Then I want to use the propertie loading and the function onTest that way: How can I do that? Answer You cannot set ref on functional components because they don’t have an instance. You may not use the ref attribute on function components because they don’t have instances. (source: https://reactjs.org/docs/refs-and-the-dom.html#accessing-refs) To make your example working you need to convert <MyComponent /> to class component.

How to delete all files in a firebase storage directory

I have a firebase storage path that looks like this. firebase.storage().ref(‘temp/test’) the “test” folder has about 25-50 files. I know there is not a way to delete the whole directory in firebase but Is there a way to iterate through all the files in a directory and deleting them one by one? Answer Is there a way to iterate through all the files in a directory and deleting them one by one? Yes, you can use the listAll() method, as follows: Note that: This method is only available for Firebase Rules Version 2 (add rules_version = ‘2’; at the top

How do I show a selected button in a row by changing CSS in an HTML site?

I have a div of buttons in line and I want the user to be able to see when they selected a button by changing the CSS and it only going back to its old state when they select another button. Is this possible? Answer Find all the buttons and add event listener to execute some javascript where you put the logic of changing the behaviour of the buttons.

Display Javascript Object In WebPage Without Knowing Its structure

I want to Display javascript document object in webpage, in the same way it is displayed in console as object opening as dropdown. Is there any way by which we can display a javascript object on webpage without knowing its structure in the same way as console does? Answer Check this out:

How to cancel all subscriptions inside UseEffect in React

I am getting this error – Can’t perform a React state update on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in a useEffect cleanup function. Here’s my useEffect hook, I used a ref called mounted to check if the component has unmounted or not but I am still getting the error when the component unmounts. (It takes about a minute for the error to show up). TIA Answer I usually store all my subscriptions on my component state and then call them when

The top two rows of a table not working in Html while using JS

I want to create a Tic Tac game but there is some problem probably in Javascript file thats why when any of the boxes of top row are clicked they are not responding … while the third one does Please help Answer It’s always a bit tricky to relay on the text() of a cell being “” because there might be some space left in the markup which can invalidate your condition. To quickly fix the issue you can add trim() to make sure to remove all leading and trailing space in the markup. I’ve created a JSFiddle to show

Lightweight web browser for testing

I have e very specific test setup in mind. I would like to start a web-browser that understands Javascript and can use HTTP proxy, point it to a URL (ideally by specifying it in the command line along with the proxy config), wait for the page to load while listening (in the proxy) requests are generated as web-page is rendered and Javascript is executed, then kill the whole thing and restart. I don’t care about how the page renders graphically at all. Which browser or tool should I use for this? Ideally it should be something self-contained that doesn’t require

How to read data From *.CSV file using javascript?

My csv data looks like this: heading1,heading2,heading3,heading4,heading5,value1_1,value2_1,value3_1,value4_1,value5_1,value1_2,value2_2,value3_2,value4_2,value5_2…. How do you read this data and convert to an array like this using Javascript?: [heading1:value1_1 , heading2:value2_1, heading3 : value3_1, heading4 : value4_1, heading5 : value5_1 ],[heading1:value1_2 , heading2:value2_2, heading3 : value3_2, heading4 : value4_2, heading5 : value5_2 ]…. I’ve tried this code but no luck!: Answer NOTE: I concocted this solution before I was reminded about all the “special cases” that can occur in a valid CSV file, like escaped quotes. I’m leaving my answer for those who want something quick and dirty, but I recommend Evan’s answer for accuracy. This

Getting cookies in a google chrome extension

I am trying to get a cookie specifically from a domain using this code: The problem is that the alert always says undefined. However, if I change to it works properly. How do I save the value to use later? Update: It appears that if I call alert(ID) from the chrome console after the script runs, it works. How can I set my code to wait until chrome.cookies.get finishes running? Answer Almost all Chrome API calls are asynchronous, so you need to use callbacks to run code in order:

What is the ‘new’ keyword in JavaScript?

The new keyword in JavaScript can be quite confusing when it is first encountered, as people tend to think that JavaScript is not an object-oriented programming language. What is it? What problems does it solve? When is it appropriate and when not? Answer It does 5 things: It creates a new object. The type of this object is simply object. It sets this new object’s internal, inaccessible, [[prototype]] (i.e. __proto__) property to be the constructor function’s external, accessible, prototype object (every function object automatically has a prototype property). It makes the this variable point to the newly created object. It