Access parent data from within child instanceMethods

[HriBB]

Already asked this question on Apollostack graphql-tools issue tracker, but this is probably a sequelize thing ...

Anyway, I have a parent->children relation on the same table, and I am trying to access parent data from child instanceMethods

This is my sequelize model Location

module.exports = function(sequelize, DataTypes) {
  return sequelize.define('Location', {
    parent_id: {
      type: DataTypes.INTEGER(11),
      allowNull: true,
    },
    name: {
      type: DataTypes.STRING,
      allowNull: false,
    },
    slug: {
      type: DataTypes.STRING,
      allowNull: false,
    }
  },{
    tableName: 'location',
    freezeTableName: true,
    instanceMethods: {
      getUrl: function() {
        // here I need to check if this instance is a child
        // and return a different url for child
        return '';
      }
    },
    classMethods: {
      associate: function(m) {
        m.Location.belongsTo(m.Location, {
          foreignKey: 'parent_id',
          as: 'Parent'
        });
        m.Location.hasMany(m.Location, {
          foreignKey: 'parent_id',
          as: 'Locations'
        });
      }
    }
  });
};

And this are my resolve functions, which is part of the Apollostack workflow.

const resolveFunctions = {
  RootQuery: {
    location(root, { slug }, context){
      return Location.find({ where: { slug }, include:[{ model: Location, as: 'Locations' }] });
    }
  },
  Location: {
    parent(location){
      return location.getParent();
    },
    locations(location){
      return location.getLocations();
    },
    url(location){
      // or here ... 
      // check if this location is child
      // and return a different url
      return location.getUrl();
    }
  }
}

What would be the best way to do this?

This is the solution I have come up with. I manually inject parent data into child, but it feels like there's a better way ...

const resolveFunctions = {
  RootQuery: {
    // ...
  },
  Location: {
    locations(location){
      if (!location.Locations) {
        return [];
      }
      // I can manually "inject" parent into each location
      // this way I can access this.parent from within getUrl() inside instanceMethods
      return location.Locations.map(l => {
        l.parent = location.dataValues;
        return l;
      });
    }
  }
}

Dialect: mysql v2.10.2
Database version: 5.7.10
Sequelize version: 3.22.0

[janmeier]

There is no way to access the parent without explictly loading it (this.getParent().then...). Its a tradeof of performance (injecting already loaded data) vs. separation (loading data where its needed) I guess.

If you're not too deeply invested in graphql-tools, have a look at https://github.com/mickhansen/graphql-sequelize/ ;)

Closing this issue, since it is neither a bug report nor a feature request.

For general sequelize questions, please use Slack, StackOverflow or Google groups.

[HriBB]

Thanks for the info and sorry for the spam ;)