Defining your validation rules

Now for the fun stuff! The RSV library comes with a number of pre-built validation routines that you can use to validate your fields. Here's how the validation works.

The rules are basically a LIST (or an array for the technically-literate), saying which form fields need to validated, in what order, what way, and what error message should be displayed to the user if they're not filled in properly. Here is a simple example:

var rules = []; // this stores all the validation rules
rules.push("required,first_name,Please enter your first name.");
rules.push("required,email,Please enter your email address.");
rules.push("valid_email,email,Please enter a valid email address.");

Here we are checking that the first name and email fields have a value and that the email address is valid. Each rules.push("...") line adds a new validation rule to the list. The "push" statements each contain a string (i.e. a bunch of characters wrapped in quotes. The push statements are all of the following form:

"[if:FIELD=VAL,]RULE,fieldname[,fieldname2[,fieldname3,date_flag]],error message"

The square bracket [] notation is a commonly used convention in programming circles to indicate that the contents are optional, in this case depending on the RULE used by the line. A full list of available validation rules can be found in the Available Validation Rules page.

Note: if you need to include commas in the error messages you must escape them with two backslashes, like so: \\,

Back to the example already!

Alright. Our form has just 5 fields. Let's validate them all, making all fields required, ensuring the email address is valid and that the "age" field is only numeric. No problem! Here's how the validation rules would look:

var rules = [];
rules.push("required,first_name,Please enter your first name.");
rules.push("required,last_name,Please enter your last name.");
rules.push("required,email,Please enter your email address.");
rules.push("valid_email,email,Please enter a valid email address.");
rules.push("required,any_integer,Please enter your age.");
rules.push("digits_only,any_integer,The age field may only contain digits.");
rules.push("required,marital_status,Please enter your marital status.");