Aggregate multiple max KO extend validations

Question

I am using ko extend validation to validate, Trying to do something like follows. ko.extend does not support multiple bindings for same type (max in this case) and it only adds first rule. Is there a way to conditionally pass the params with a function? or my only way out is writing a custom validation?

         myModel.prop2.extend({
            max: {
                onlyIf: function () {

                    var test = myModel.prop1() != undefined &&
                        myModel.prop1() !== "Percentage";
                    return test;
                },
                params: 100000
            }
        }).extend({
            max: {
                onlyIf: function() {
                    return myModel.prop1() != undefined &&
                        myModel.prop1() === "Percentage";
                },
                params: 100
            }
        });

Answer 1

I'm not sure, what you are really trying to achieve. But the way that you tried is not valid way i think. So, you May have to use something like below,

Solution 1:

You can supply a validator or an array of them.

var testObj = ko.observable(3).extend({
        validation: [{
            validator: function (val, someOtherVal) {
                return val === someOtherVal;
            },
            message: 'Must Equal 5',
            params: 5
        },{
            validator: function (val) {
                return val !== 8;
            },
            message: 'Can not be 8',
            params: 8
        }]
    });

Solution 2:

ko.validation.rules['compareTo'] = {
    message: "Compare to",
    validator: function (val, params) {
        if (val === null || params.value() === null)
            return params.allowNull;
        switch (params.way) {
            case "<": return val < params.value();
            case "<=": return val <= params.value();
            case ">": return val > params.value();
            case ">=": return val >= params.value();
            default: throw new Error("params is not well defined");
        }
    }
}

myModel.prop2.extend({ compareTo: { 
                       message:"your message", 
                       params: { 
                                   way: ">=", 
                                   value: model.otherObs, 
                                   allowNull: true 
                       }, 
                       onlyIf: function () { /*your test*/ } 
                    }});

Hope this helps.,

Answer 2

Found a solution,

.extend({
            validation: [{
                validator: function (val, someOtherVal) {
                    if (myModel.prop1()() !== "Percentage") {
                        return val < someOtherVal;
                    }
                    return true;
                },
                message: "Too big!!!!",
                params: 100000
            }]
        })