planka/server/api/helpers/create-card-label.js

module.exports = {
  inputs: {
    card: {
      type: 'ref',
      required: true
    },
    label: {
      type: 'ref',
      required: true
    },
    request: {
      type: 'ref'
    }
  },

  fn: async function(inputs, exits) {
    const cardLabel = await CardLabel.create({
      cardId: inputs.card.id,
      labelId: inputs.label.id
    })
      .intercept('E_UNIQUE', 'conflict')
      .fetch();

    sails.sockets.broadcast(
      `board:${inputs.card.boardId}`,
      'cardLabelCreate',
      {
        item: cardLabel
      },
      inputs.request
    );

    return exits.success(cardLabel);
  }
};