Forms are a great way to gather information from visitors and allow them to submit information to your website, for example, Submit feedback<\/strong> to the website. Mostly, we want to ensure that customers don’t leave specific form fields blank, or we want to limit a field to a certain type of input such as characters, numbers, email addresses, etc. At this time we need to validate form fields. If we validate form input fields before the data is sent to the database or website, then the visitor gets a chance to correct the data. The goal of Form Validation<\/strong> is to ensure that the user provides necessary and properly formatted information needed to complete the form submission. Moodle Quick Forms<\/strong> are standard and most used method for form creation. This is the easiest method to apply validation on moodle form. We use this inside the moodleform::definition<\/strong> method. First, we add an element in form after that we can apply addRule()<\/strong> for validation. There are some common rule types that we use via this method like required, maxlength, minlength, email, regex, numeric, etc. Below is the syntax to use addRule()<\/strong>. <\/p>\n Now we are going to describe the syntax:<\/p>\n Now here is the example of fullname field with required and maxlength rules : } This is another method to apply validation on moodle form. This is commonly used for custom validation. When we create a form by extending moodleform <\/strong>class, we need to define a method validation()<\/strong> to make our own custom validation for the form. After that, we need to call the moodleform parent validation()<\/strong> method. Then we will apply our own rules. As a result, this will return an array of \u2018errors\u2019<\/strong> or \u2018null\u2019<\/strong>. Here is the syntax:<\/p>\n
\nAs we all know, Moodle has its own Forms library which has lots of accessibility code and error checking by default. Form API<\/strong> is used to create a form. When we create the form by using this Form API<\/strong> we need to include formslib.php<\/strong>. So we have two ways to add Form Validation in the forms lib<\/strong>. These are explained as follows:<\/p>\n\n
MoodleQuickForm::addRule()<\/h3>\n
\n$mform->addRule('elementname', get_string('error'), 'rule type', 'extraruledata', 'client\u2019);
\n<\/code><\/p>\n\n
\n
\nrequire_once(\"$CFG->libdir\/formslib.php\");
\n class edit_form extends moodleform {
\n \/\/Add elements to form
\n public function definition() {
\n global $CFG;
\n $mform = $this->_form; \/\/ Don't forget the underscore!
\n $mform->addElement('text','fullname', get_string('fullnamecourse'), ['size' => 50]);
\n $mform->addHelpButton('fullname', 'fullnamecourse');
\n $mform->addRule('fullname', get_string('maximumchars', '', 1333), 'maxlength', 1333); \/\/maxlength rule applied
\n $mform->addRule('fullname', get_string('missingfullname'), 'required', null, 'client'); \/\/required rule applied
\n $mform->setType('fullname', PARAM_TEXT); \/\/Set type of element<\/p>\n
\n}
\n<\/code><\/p>\nmoodleform::validation()<\/h3>\n