react-middle-truncate

NOTE: this fork contains a few improvements including:

• An improved algorithm for finding the truncated string, guaranteed to take up maximal space in the allowed area
• Overriden copy behavior should always work (previously triple-click selections did not work)
• Karma tests were previously broken, but now run correctly

A React component for intelligently truncating text in the middle of the string with an ellipsis. You can see the component in action in this demo.

Installation

npm install react-middle-truncate --save

Usage

The truncation point is determined by taking into account the inherited font CSS properties of the element, and rendering the result to Canvas in order to dynamically calculate the width of the text. Should the width of the text not fit into the available space to render, truncation is applied. The result of which looks like this:

import MiddleTruncate from 'react-middle-truncate';

<MiddleTruncate
  text="Hello world this is a really long string"
  start={/Hello\sworld/}
  end={6} />

You'll note from the code sample above we can use the start and end props to determine how much of the start and end of the string to preserve. These props can either be numeric, which indicates how many characters of the string from that direction to preserve, or you can provide a Regular Expression to dynamically match parts of the string.

In the case of using a Regular Expression for the end prop, remember to match from the end of the pattern using the $ flag.

Options

Prop	Type	Description	Default
text	String	The input text to truncate if there isn't enough space to render the entire string.	''
ellipsis	String	The ellipsis to use when the text is truncated.	'...'
start	Number RegExp	The number of characters or a Regular Expression match from the start of the text to preserve.	0
end	Number RegExp	The number of characters or a Regular Expression match from the end of the text to preserve.	0
smartCopy	Boolean String	Can be one of the following: false, 'partial' or 'all'. Allows the the full un-truncated text to be copied to the user's clipboard when they select and copy the truncated text.	'all'
onResizeDebounceMs	Number	A delay in milliseconds to debounce the window resize event listener.	100

Why and when to middle truncate?

We have access to CSS text truncation with the text-overflow: ellipsis; which will truncate the text at the end of a string for us. So why do you need middle truncation, and when should you use it?

Ultimately it boils down to whether text at the end or in the middle of the string is more likely to differentiate the item.

In the case of a street address, the end of the string is likely to be less important in helping the user to differentiate items from one another, as most strings of that category are likely to end in road, street, avenue etc... So in that case truncating at the end of the string would be a better solution.

In the case of a connection string or a URL, the start and/or end of the string is likely to contain more valuable information to help the user differentiate items from one another, such as the protocol and sub domain parts at the start, and the port number at the end of the string are more likely to be different. In that case truncating in the middle of the string would be a better solution.

Contributing

Pull requests of any kind are welcome from the community. Please ensure you have read the guidelines for Contributing and this project's Code of Conduct before raising a pull request.

Maintainers

• Matt Fairbrass @matt_d_rat

License

MIT License