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Tag: reactjs

Method for coverting all Firestore Timestamps in a snapshot to JS dates?

How would you write a method to convert all Firestore Timestamps in a snapshot to JavaScript Dates? For example, a snapshot from a posts collection might return a couple Firestore Timestamps (createdDtTm, modifyDtTm): Converting the individual dates is simple enough by mapping over the array and using the toDate() method for each Timestamp (e.g., createDtTm.toDate()) But what is a more

Create sub-headings in a react dropdown component

I have created a drop down menu using the react component . The code is below: The person object is as follows: I was wondering whether it is possible to have sub-headings within this drop down menu in order to group the people (e.g. Men, Women). I have found it possible when using plain javascript but I can’t seem to

When should I use componentDidMount?

In React componentDidMount is used during the mounting phase, for example, one can setState and wrap it in componentDidMount. But, one can use setState directly and then render the component. In which cases should I prefer componentDidMount for a mounting phase? Answer It’s useful for several things: Starting ajax As the documentation says, doing subscriptions to things (for instance, if

React Native Error (Invalid Element Type)

when starting my App on my iOS device I get this error: Error: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but gor: undefined. You likely forgot to export your component from the file it’s defined in, or you might have mixed up default and named imports. Check the render method of

Context API problem – object is undefined

I’ve been always using Redux, but I finally decided to try to play with Context API, but apparently I’m missing something. I get an error “TypeError: Object(…)(…) is undefined” in App.js, weather and details appear to be undefined. Could you please check out my code in order to help me out in finding a mistake? I thought I should have

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