Jump to main content Jump to doc navigation

Validation in FormIt

As of FormIt 2.2.9, all fields will automatically have html_entities applied. To allow HTML tags to be saved/stored, you will need to use the allowSpecialChars validator on each field, that should save raw html tags.

As of FormIt 1.4.0, validation has changed. The old method of doing validation on the input names will still work until FormIt 2.0.0, when it will be removed. It is recommended to use the new way by using the &validate property.

As of FormIt 1.1.4, all fields will automatically have stripTags applied. To allow HTML tags to be saved/stored, you will need to use the allowTags validator on each field, stipulating which tags are permitted.

Validation can simply be done by adding the fields to validate to the &validate property on the Snippet call. For example, to make the username field required, you could do:

[[!FormIt? &validate=`username:required`]]

Validators can also be "chained", or done in succession. The following first checks to see if required, then strips all tags from the post:

[[!FormIt? &validate=`text:required:stripTags`

Multiple fields and validators are separated by commas:


FormIt allows you to split the validators on multiple lines if you so choose.

Note: Don't use backticks ` inside a validate call. Use carets ^ instead:

[[!FormIt? &validate=`date:required:isDate=^%m/%d/%Y^`]]

This will fix the call and cause it to work properly.

A general error message for validators, useful if no errors are showing but validation is failing, is used with the following placeholder:


This will contain a validation error message, which can be set using the &validationErrorMessage property, and using [[+errors]] in the property value, which will be replaced by all the field errors.

Also, there is a 1/0 placeholder as well:


Built-In Validators

name function parameter example
blank Is field blank? nospam:blank
required Is field is not empty? username:required
password_confirm Does field match value of other field? The name of the password field password2:password_confirm=^password^
email Is a valid email address? emailaddr:email
minLength Is field at least X characters long? The min length. password:minLength=^6^
maxLength Is field no more than X characters long? The max length. password:maxLength=^12^
minValue Is field at least X? The minimum value. donation:minValue=^1^
maxValue Is field no higher than X? The maximum value. cost:maxValue=^1200^
contains Does field contain string X? The string X. title:contains=^Hello^
strip Strip a certain string from the field. The string to strip. message:strip=^badword^
stripTags Strip all HTML tags from the field. Note that this is on by default. An optional list of allowed tags. message:stripTags
allowTags Don't strip HTML tags in the field. Note that this is off by default. content:allowTags
isNumber Is the field a numeric value? cost:isNumber
allowSpecialChars Don't replace HTML special chars with their entities. Note that this is off by default. message:allowSpecialChars
isDate Is the field a date? An optional format to format the date. startDate:isDate=^%Y-%m-%d^
regexp Does field match an expected format? A valid regular expression to match against. secretPin:regexp=^/[0-9]{4}/^

Custom Validators

Validators can also be custom Snippets. You can do this by simply specifying the snippet name in the customValidators property:

[[!FormIt? &customValidators=`isBigEnough`]]

As of FormIt 1.2.0, all custom validators must be specified in the customValidators property, or they will not be run.

And then as a validator on the &validate property:

[[!FormIt? &validate=`cost:isBigEnough`]]

Then in your Snippet, "isBigEnough":

$value = (float)$value;
$success = $value > 1000;
if (!$success) {
    // Note how we can add an error to the field here.
    $validator->addError($key,'Not big enough!');
return $success;

The Validator will send the following properties to the snippet, in the $scriptProperties array:

name function
key The key of the field being validated.
value The value of the field that was POSTed.
param If a parameter was specified for the validator, this is it.
type The name of the validator (or snippet)
validator A reference to the fiValidator class instance.

Custom Error Messages

As of FormIt 2.0-pl, you can override the error messages displayed by the validators, by sending the appropriate property:

validator property
blank vTextBlank
required vTextRequired
password_confirm vTextPasswordConfirm
email vTextEmailInvalid, vTextEmailInvalidDomain
minLength vTextMinLength
maxLength vTextMaxLength
minValue vTextMinValue
maxValue vTextMaxValue
contains vTextContains
isNumber vTextIsNumber
isDate vTextIsDate
regexp vTextRegexp

You can also specify the message per-field by prefixing the field key in the property. For example, to override the "required" validator message, simply pass in your FormIt call:

    &vTextRequired=`Please enter a value for this field.`
    &subject.vTextRequired=`Please enter a subject.`

This will use the &subject.vTextRequired for the subject field, and then fallback to the &vTextRequired message for all other fields.

See Also

  1. FormIt.Hooks
    1. FormIt.Hooks.email
    2. FormIt.Hooks.FormItAutoResponder
    3. FormIt.Hooks.math
    4. FormIt.Hooks.recaptcha
    5. FormIt.Hooks.redirect
    6. FormIt.Hooks.spam
    7. FormIt.Hooks.FormItSaveForm
  2. FormIt.Validators
  3. FormIt.FormItRetriever
  4. FormIt.Tutorials and Examples
    1. FormIt.Examples.Custom Hook
    2. FormIt.Examples.Simple Contact Page
    3. FormIt.Handling Selects, Checkboxes and Radios
    4. FormIt.Using a Blank NoSpam Field
  5. FormIt.FormItCountryOptions
  6. FormIt.FormItStateOptions