isEmail

Summary

Waterline provides built-in validation rules for Sails.js models, allowing fine-grained control over data integrity. While the previous chapter covered basic type validation (number, string, boolean, etc.) and required, this chapter dives deeper into additional validation rules.

For example, the isEmail validation rule ensures that an attribute contains a valid email format. Without this rule, any string could be stored as an email.

To enforce email validation:

email: {
  type: 'string',
  isEmail: true,
  allowNull: false, // Prevents null values
  required: true // Ensures it's always provided
}

Key takeaways:

• Validation rules run in Node.js before the data reaches the database.

• isEmail ensures proper email format.

• Allowing null values requires explicit handling (allowNull: false).

• Required attributes must always be provided (required: true).

If a non-email string is passed, Sails will return an error:

await User.create({ email: "invalidString" }); 
// Error: "email" is not a valid email address

A properly formatted email will pass validation:

await User.create({ email: "hobbit@frodo.com" }); // Success!

Waterline validation protects your database from bad data, ensuring that only correctly formatted values are accepted.

Transcript

So this chapter is all about Waterline validation rules—built-in automatic validations for attributes. In the last chapter, we covered basic type checks (number, string, boolean, ref, JSON) and required attributes. Now, we’ll explore fine-grained validation rules that protect your database's integrity.

For example, let’s modify our User model to include an email attribute:

email: {
  type: 'string'
}

Right now, any string can be stored, even if it’s not an email. We need validation rules to prevent this.

Sails provides isEmail validation, which ensures the value looks like an email:

email: {
  type: 'string',
  isEmail: true
}

These rules run in JavaScript before the database operation. That means:

1. They apply when creating or updating records.

2. If a value fails validation, the request is rejected.

Let’s test this in Guppy:

await User.create({ email: "randomString" });

This fails with an error:

Could not use specified email. Violated one or more validation rules.

But this works:

await User.create({ email: "duke@example.com" });

To prevent null values, we add:

allowNull: false

And to require an email for every user, we add:

required: true

Now, if we test with:

await User.create({ email: null });

We get an error because null is not allowed.

Validation rules give you control over your data and prevent unexpected values from entering your database. Next, we’ll look at more useful rules in this chapter.