XIN Rules?
What are XIN Rules
XIN Rules validate your input and prevent you from moving forward if you forget to fill in a required field. They can also be used to enforce dependencies between fields. (i.e. If A1 is selected in question A and if A2 is selected in question B, then give examiner a break and skip question 3 and 4.)
For example:
A. Do you smoke?
- A1: Yes
- A2: No
B: How often do you smoke? #Skip question B if A2 "No" response was given for question A
How to use XIN Rules
Add XIN Rules to form elements
All elements are required if no rule is specified, unless it is part of a group.
-
PHP
php $this->XINRegisterRule( "field_name1", array("field_name2{@}=={@}yes|maybe|sure"), "Required." );
- PHP (with grouping)php $this->XINRegisterRule( "field_name", // field name on which the rule is applied array("field_name{@}=={@}"), // rule "Required.", // message "group_1" // group [if field is a part of a group] );
- LINST
php
field_name1{-}Required.{-}field_name2{@}=={@}yes|maybe|sure
NOTE: When adding XIN rules some elements are implicitly added to a group in NDB_BVL_Instrument.class.inc. In consequence, a group name needs to be specified when registering a rule. A group name is necessary for the following elements:
php $this->addHourMinElement(); // Group name: {$fieldName}_group $this->addTextElement(); // Group name: {$fieldName}_group $this->addNumericElement(); // Group name:{$fieldName}_group $this->addDateElement(); // Group name: {$fieldName}_dategroup
Field is never required
$this->XINRegisterRule(
"field_name",
array("field_name{@}=={@}NEVER_REQUIRED"),
"Not required",
"group1"
);
Field is required based on value of another field (check for equality)
$this->XINRegisterRule(
"field_name1",
array("field_name2{@}=={@}yes"),
"Required."
);
Field is required based on value of another field (check for equality with multiple valid values)
$this->XINRegisterRule(
"field_name1",
array("field_name2{@}=={@}yes|maybe|sure"),
"Required."
);
Multiple rules applied in AND fashion
$this->XINRegisterRule(
"field_name3",
array("field_name1{@}=={@}yes", "field_name2{@}=={@}no"),
"Required."
);
Multiple rules applied in OR fashion
$this->XINRegisterRule(
"field_name3",
array("field_name1{@}=={@}yes|field_name2{@}=={@}yes"),
"Required."
);
Validating multi-selects
Currently, multi-selects do not work well within XINRules. To validate that a multi-select has been filled, an additional validation function is a best practice, to ensure that an informative error message is displayed for the user, if the multi-select fails validation and the form is not saved.
function _page1() {
...
$this->addSelect(
"multiselect_ex",
"Multi-Select Example",
$options,
["multiple"]
);
...
$this->form->addFormRule(array(&$this,'validateMultiSelects'));
}
function validateMultiSelects($values)
{
$errors = array();
if(empty($values['multiselect_ex'])){
$errors['multiselect_ex'] = "Required.";
}
return $errors;
}