react-githubish-mentions

A wrapper for a textarea to offers autocomplete suggestions when triggered by @ or # or whatever

Installation

yarn add react-githubish-mentions

What's it do

It strives to do exactly what GitHub does when you type # or @.

How's it different from react-mentions

react-mentions is great! but I needed:

• something a little more flexible (like letting me pass in my own component with avatars for individual Menu items)
• a menu that uses a portal instead of position: 'absolute'
• something with pixel-perfect caret positioning
• something that let's me use controlled components, like redux-form

Usage

Stick it around your component

Example:

// MenuItem.js
const MenuItem = (props) => {
  // react-githubish-mentions provides `active` you provide everything else
  const {active, value} = props;
  const customStyle = {
    background: active ? 'blue' : 'white'
  };
  return (
    <div style={customStyle}>
      {value}
    </div>
  )
};
export default MenuItem;

// in form.js
import {MentionWrapper, MentionMenu} from 'react-githubish-mentions';
import MenuItem from './MenuItem';

const Form = (props) => {
  const atQuery = async (query) => {
    const {teamMembers} = this.props;
    // You must provide a `value` field. Everything else is optional. All this data will be passed to your custom MenuItem
    const tm = teamMembers.map((teamMember) => ({...teamMember, value: teamMember.name}));
    return tm.filter((member) => member.value.startsWith(query))
  };

  return (
    <MentionWrapper placeholder="Type your outcome here">
      <MentionMenu className="mentionMenuStyle" trigger="@" item={MenuItem} resolve={atQuery}/>
      <MentionMenu className="mentionMenuStyle" trigger="#" item={MenuItem} resolve={hashQuery}/>
    </MentionWrapper>
    )
};

API

MentionWrapper

Think of this as <textarea>. Everything except the 2 options below get passed directly to the HTML component.

Options:

• getRef: a custom ref, because react yells if you call something ref.
• component: defaults to "textarea" you can pass in "input" or even a custom component if you want (TODO)
• onChange(event, newValue): your standard onChange event handler, but with a newValue argument added to support clicking an option with the mouse.

MentionMenu

Think of this as a trigger, written in JSX. Any style or className is passed to the menu that will pop up.

Options:

• trigger: The keystroke to watch for. Usually a single character like @ or #
• replace(trigger, userObject): A function dictating how to autocomplete the sentence. Default is (userObj, trigger) => `${trigger}${userObj.value} ` . If you wanted to write a trigger for emojis, you probably don't want the : trigger to remain, and you want the character, not the text value, so you might use (userObj) => `${userObj.emoji} `
• resolve(query): An AsyncFunction that receives a text query (the part after the trigger, e.g. query('@foo') === 'foo') and returns an array of objects, where each object has a value key which is the string that will be injected into the textarea.
• item: A custom menu item that you provide. See example above.

FAQ

Q: I'm debugging the menu & I don't see it in the DOM tree. What voodoo is this?

A: It's there, but it created a portal & lives in its own react root. This is the only surefire way to guarantee the menu doesn't get clipped or scrolled away. To learn more, see react-portal-hoc

Q: How is the menu position calculated?

A: Very carefully, using textarea-caret. Until Document.caretPositionFromPoint() is a thing, it's the best there is.

Q: How do I filter the results in my resolve function?

A: There are 100s of ways to filter, you could go naive with a startsWith or indexOf or go extreme with a fuzzy or levenshtein distance. Chances are, each trigger will warrant a different filter. This package does one thing, and does it well. It leaves the filtering up to your resolve function.

License

MIT