Mentions plugin

<textarea id="mentions">
  <p>Type "<kbd>@</kbd>" followed immediately by one or more characters.</p>
  <p>For example: @a</p>
</textarea>

textarea#mentions {
  height: 350px;
}

div.card,
.tox div.card {
  width: 240px;
  background: white;
  border: 1px solid #ccc;
  border-radius: 3px;
  box-shadow: 0 4px 8px 0 rgba(34, 47, 62, .1);
  padding: 8px;
  font-size: 14px;
  font-family: -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;
}

div.card::after,
.tox div.card::after {
  content: "";
  clear: both;
  display: table;
}

div.card h1,
.tox div.card h1 {
  font-size: 14px;
  font-weight: bold;
  margin: 0 0 8px;
  padding: 0;
  line-height: normal;
  font-family: -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;
}

div.card p,
.tox div.card p {
  font-family: -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;
}

div.card img.avatar,
.tox div.card img.avatar {
  width: 48px;
  height: 48px;
  margin-right: 8px;
  float: left;
}

/* Script to import faker.js for generating random data for demonstration purposes */
tinymce.ScriptLoader.loadScripts(['https://cdn.jsdelivr.net/npm/faker@5/dist/faker.min.js'], function() {

  /*
  ** This is to simulate requesting information from a server.
  **
  ** It has 2 functions:
  ** fetchUsers() - returns a complete list of users' ids and names.
  ** fetchUser(id) - returns the full information about a single user id.
  **
  ** Both of these functions have a slight delay to simulate a server request.
  */
  var fakeServer = (function () {
    /* Use TinyMCE's Promise shim */
    var Promise = tinymce.util.Promise;

    /* Some user profile images for our fake server (original source: unsplash) */
    var images = [
      'Abdullah_Hadley', 'Abriella_Bond', 'Addilynn_Dodge', 'Adolfo_Hess', 'Alejandra_Stallings', 'Alfredo_Schafer', 'Aliah_Pitts', 'Amilia_Luna', 'Andi_Lane', 'Angelina_Winn', 'Arden_Dean', 'Ariyanna_Hicks', 'Asiya_Wolff', 'Brantlee_Adair', 'Carys_Metz', 'Daniela_Dewitt', 'Della_Case', 'Dianna_Smiley', 'Eliana_Stout', 'Elliana_Palacios', 'Fischer_Garland', 'Glen_Rouse', 'Grace_Gross', 'Heath_Atwood', 'Jakoby_Roman', 'Judy_Sewell', 'Kaine_Hudson', 'Kathryn_Mcgee', 'Kayley_Dwyer', 'Korbyn_Colon', 'Lana_Steiner', 'Loren_Spears', 'Lourdes_Browning', 'Makinley_Oneill', 'Mariana_Dickey', 'Miyah_Myles', 'Moira_Baxter', 'Muhammed_Sizemore', 'Natali_Craig', 'Nevaeh_Cates', 'Oscar_Khan', 'Rodrigo_Hawkins', 'Ryu_Duke', 'Tripp_Mckay', 'Vivianna_Kiser', 'Yamilet_Booker', 'Yarely_Barr', 'Zachary_Albright', 'Zahir_Mays', 'Zechariah_Burrell'
    ];

    /* Create an array of 200 random names using faker.js */
    var userNames = [];
    for (var i = 0; i < 200; i++) {
      userNames.push(faker.name.findName());
    };

    /* This represents a database of users on the server */
    var userDb = {};
    userNames.map(function (fullName) {
      var id = fullName.toLowerCase().replace(/ /g, '');
      return {
        id: id,
        name: fullName,
        fullName: fullName,
        description: faker.name.jobTitle(),
        image: '/unsplash/uifaces-unsplash-portrait-' + images[Math.floor(images.length * Math.random())] + '.jpg'
      };
    }).forEach(function(user) {
      userDb[user.id] = user;
    });

    /* This represents getting the complete list of users from the server with the details required for the mentions "profile" item */
    var fetchUsers = function() {
      return new Promise(function(resolve, _reject) {
        /* simulate a server delay */
        setTimeout(function() {
          var users = Object.keys(userDb).map(function(id) {
            return {
              id: id,
              name: userDb[id].name,
              image: userDb[id].image,
              description: userDb[id].description
            };
          });
          resolve(users);
        }, 500);
      });
    };

    /* This represents requesting all the details of a single user from the server database */
    var fetchUser = function(id) {
      return new Promise(function(resolve, reject) {
        /* simulate a server delay */
        setTimeout(function() {
          if (Object.prototype.hasOwnProperty.call(userDb, id)) {
            resolve(userDb[id]);
          }
          reject('unknown user id "' + id + '"');
        }, 300);
      });
    };

    return {
      fetchUsers: fetchUsers,
      fetchUser: fetchUser
    };
  })();

  /* These are "local" caches of the data returned from the fake server */
  var usersRequest = null;
  var userRequest = {};

  var mentions_fetch = function (query, success) {
    /* Fetch your full user list from somewhere */
    if (usersRequest === null) {
      usersRequest = fakeServer.fetchUsers();
    }
    usersRequest.then(function(users) {
      /* `query.term` is the text the user typed after the '@' */
      users = users.filter(function (user) {
        return user.name.indexOf(query.term.toLowerCase()) !== -1;
      });

      users = users.slice(0, 10);

      /* Where the user object must contain the properties `id` and `name`
        but you could additionally include anything else you deem useful. */
      success(users);
    });
  };

  var mentions_menu_hover = function (userInfo, success) {
    /* Request more information about the user from the server and cache it locally */
    if (!userRequest[userInfo.id]) {
      userRequest[userInfo.id] = fakeServer.fetchUser(userInfo.id);
    }
    userRequest[userInfo.id].then(function(userDetail) {
      var div = document.createElement('div');

      div.innerHTML = (
      '<div class="card">' +
        '<img class="avatar" src="' + userDetail.image + '"/>' +
        '<h1>' + userDetail.fullName + '</h1>' +
        '<p>' + userDetail.description + '</p>' +
      '</div>'
      );

      success(div);
    });
  };

  var mentions_menu_complete = function (editor, userInfo) {
    var span = editor.getDoc().createElement('span');
    span.className = 'mymention';
    span.setAttribute('data-mention-id', userInfo.id);
    span.appendChild(editor.getDoc().createTextNode('@' + userInfo.name));
    return span;
  };

  var mentions_select = function (mention, success) {
    /* `mention` is the element we previously created with `mentions_menu_complete`
      in this case we have chosen to store the id as an attribute */
    var id = mention.getAttribute('data-mention-id');
    /* Request more information about the user from the server and cache it locally */
    if (!userRequest[id]) {
      userRequest[id] = fakeServer.fetchUser(id);
    }
    userRequest[id].then(function(userDetail) {
      var div = document.createElement('div');
      div.innerHTML = (
        '<div class="card">' +
        '<img class="avatar" src="' + userDetail.image + '"/>' +
        '<h1>' + userDetail.fullName + '</h1>' +
        '<p>' + userDetail.description + '</p>' +
        '</div>'
      );
      success(div);
    });
  };

  tinymce.init({
    selector: 'textarea#mentions',
    plugins: 'mentions',
    content_style: '.mymention{ color: gray; }' +
    'body { font-family:Helvetica,Arial,sans-serif; font-size:14px }',

    mentions_selector: '.mymention',
    mentions_fetch: mentions_fetch,
    mentions_menu_hover: mentions_menu_hover,
    mentions_menu_complete: mentions_menu_complete,
    mentions_select: mentions_select,
    mentions_item_type: 'profile'
  });
});