Forms

Igo.js provides structured form handling with schema-based validation and type conversion.

Schema Definition

const schema = {
  attributes: [
    { name: 'name',      type: 'text' },
    { name: 'email',     type: 'text' },
    { name: 'age',       type: 'int' },
    { name: 'price',     type: 'float' },
    { name: 'birthdate', type: 'date', format: 'DD/MM/YYYY' },
    { name: 'active',    type: 'boolean' },
    { name: 'tags',      type: 'array', item_type: 'text' },
  ]
};

Attribute Types

Type	Conversion	Notes
text	String or null	Trimmed
int	parseInt()	Spaces removed ('1 234' → 1234)
float	parseFloat()	Comma replaced by dot ('12,5' → 12.5)
number	Number()
date	moment(value, format).toDate()	Requires format option
boolean	true / false	Use allownull: true for nullable
array	Array	Use item_type for typed items
custom	attr.convert(value)	Custom converter function

Attribute Options

{
  name: 'field',
  type: 'int',
  default: 0,           // Default value if null
  allownull: true,       // For booleans: allow null instead of false
  item_type: 'int',      // For arrays: type of items
  format: 'YYYY-MM-DD',  // For dates: moment format
  convert: (v) => v,     // For custom type: converter function
}

Form Class

Create a form class with a validate method:

const { Form } = require('@igojs/server');

class UserForm extends Form(schema) {
  validate(req) {
    req.checkBody('name', 'error.name.required').notEmpty();
    req.checkBody('email', 'error.email.invalid').isEmail();
    req.checkBody('age', 'error.age.invalid').isInt({ min: 0, max: 150 });
  }
}

Usage in Controllers

app.post('/users', (req, res) => {
  const form = new UserForm().submit(req);

  if (form.errors) {
    req.flash('form', form);
    return res.redirect('/users/new');
  }

  const values = form.getValues();
  await User.create(values);
  res.redirect('/users');
});

Processing Steps

When form.submit(req) is called:

1. Sanitize — Trim whitespace, normalize numbers
2. Validate — Run your validate(req) method
3. On error — Store errors, revert to original string values
4. Convert — Convert strings to target types (int, date, boolean...)

Validation Methods

Validation is built on validator.js:

req.checkBody('field', 'error.key').notEmpty();
req.checkBody('field', 'error.key').isEmail();
req.checkBody('field', 'error.key').isInt({ min: 0 });
req.checkBody('field', 'error.key').isFloat();
req.checkBody('field', 'error.key').isLength({ min: 3, max: 50 });
req.checkBody('field', 'error.key').match(/^[A-Z]+$/);
req.checkBody('field', 'error.key').custom(async (value) => {
  return value !== 'forbidden';
});

Other available methods: checkQuery(), checkParam(), addError(), hasError().

Error Handling

const errors = req.getValidationErrors();
// null if no errors, or: { fieldName: { msg: 'error.key' }, ... }

if (form.errors) {
  // form.errors has the same structure
  req.flash('form', form);
  return res.redirect('/form');
}