jQuery ValidationEngine: How to validate that at least one of a set of fields is not empty?

In our project we are using ValidationEngine, and we don't have the ability to replace it with another plug-in.

Our form has ten inputs and some of them are optional, but at least one of the optional fields 开发者_运维问答must be included.

So, how do you validate inputs in this case?

Sample:

form
  input1
  input2
  intpu3

input1: required

At least one of input2 and input3 must be present -- if both are empty validation should fail.

The validation engine now supports group Validation.Go to jQuery form validation plugin @ github and ake a look at groupRequired. The syntax looks something like this.

<input value="" class="validate[groupRequired[payments]]" type="text" name="creditcard" id="creditcard" />
<input class="validate[groupRequired[payments]]" type="text" id="paypal" name="paypal"/>

It appears that the ValidationEngine plugin allows you to specify a validation rule which uses a custom function to determine validity.

If you add the validate class on input1 like so...

<input id="input1" class="validate[required,funcCall[myValidationFunction]]" />

Then ValidationEngine will use the following function. You can pretty much put any kind of logic in there. If I read your scenario correctly, this should accomplish what you're after.

function myValidationFunction() {
  var input1 = $.trim($("#input1").val());
  var input2 = $.trim($("#input2").val());
  var input3 = $.trim($("#input3").val());

  if (input1.length == 0) {
    return "input1 is required";
  }

  if (input2.length == 0 && input3.length == 0) {
    return "Either input2 or input3 is required";
  }

  // We don't need to return anything if there is no error.
}

Here's a link to the _funcCall function in the source code: https://github.com/posabsolute/jQuery-Validation-Engine/blob/master/js/jquery.validationEngine.js#L574

In case someone wants to make groupRequired work for checkboxes, you need to add error messages to your language file for groupRequired. e.g. if it is jquery.validationEngine-en.js, it should be like this:

"groupRequired": {
  "regex": "none",
  "alertText": "* You must fill one of the following fields",
  "alertTextCheckboxMultiple": "* Please select an option",
  "alertTextCheckboxe": "* This checkbox is required"
}

One solution could be to attach validations before validating and removing after validation is over.

jQuery(document).ready(function(){
    jQuery("#formID").validationEngine();

    $("#formID").bind("jqv.form.validating", function(event){
        var fieldsWithValue = $('input[type=text]').filter(function(){
            if($(this).val().length>0){
                return true;
            }
        });
        if(fieldsWithValue.length<1){
            $('input[type=text]').addClass('validate[required,funcCall[requiredOneOfGroup]]');
        }
    });

    $("#formID").bind("jqv.form.result", function(event, errorFound){
        $('input[type=text]').removeClass('validate[required,funcCall[requiredOneOfGroup]]');
    });
});

function requiredOneOfGroup(field, rules, i, options){
    var fieldsWithValue = $('input[type=text]').filter(function(){
        if($(this).val().length>0){
            return true;
        }
    });
    if(fieldsWithValue.length<1){
        return "At least one field in this set must have a value.";
    }
}

!!$('#input2,#input3').filter('[value]').length

There is a provision in jquery validation plugin to make grope of of elements.

groups: {groupName: "text1 text2 text3 .. so on"}

errorPlacement: function(error, element) {
                    // Write Done your business logic to display error 

             if ( element.attr("name") == "text1" -- define other text elements also) {
               error.insertAfter("#error_location_placeholder_id");
                    }else{
               error.insertAfter(element);
             }               

           }

and you business validation in rules method for at least one must be not empty logic

groupName:{

                    required: function(element) {
// Your business logic for validation

                        if( $("#text1").val().length > 0 ){
                            return false;
                        }else{
                            return true;
                        }

                    }
                }