React.js Code Snippets

A context provider and consuming hook that manage polling for user login status. This is useful for any app that has any semblance of authentication.

A React hook detecting whether at least one of a provided set of keys is pressed. Accepts an array of strings each representing a KeyBoardEvent's key value. Returns a boolean: true if one of them is pressed, false if not.

A React hook detecting whether a key is pressed. Accepts a string representing a KeyBoardEvent's key value. Returns a boolean: true if it's pressed, false if not.

A React hook using the Page Visibility API to determine whether the current tab is active / in focus.

A React hook for tracking and detecting the browser dark mode state. Always returns a boolean indicating whether the device is in dark mode true in dark mode, false when not.

A React hook for tracking and retrieving the device size. Always returns a string indicating the current device size (sm, md, lg, etc).

Plot some points on a chart and color them in.

Make a line chart from with domain 0 to 1 and range from y_min to y_max. With red line.

In case you want to see more than just x at the interval [0, 1]. See the implementation of the range() function.

For when x and y values are dependent on a third value. See the implementation of the range() function.