剑道下拉默认选择

Question

I've a Kendo dropdown like below:

KM.ddlModel.bind("loaded", function () {
        $("#dvDDL").kendoDropDownList({
            dataTextField: "Text",
            dataValueField: "Value",
            dataSource: KM.ddlModel.cmg
        });

Now I would like to set the selected value based on a condition. How can I do it?

Answer 1

There are many ways you can do this.

At its simplest (a true or false condition), you can do the following:

KM.ddlModel.bind("loaded", function () {
        $("#dvDDL").kendoDropDownList({
            dataTextField: "Text",
            dataValueField: "Value",
            dataSource: KM.ddlModel.cmg,
            value: (<insert condition>) ? "true" : "false"
        });
}

If you condition is more complicated you can do:

function evaluateCondition() {

    var returnValue;

    // code to decide what the returnValue is

    return returnValue;
}



KM.ddlModel.bind("loaded", function () {

        var value = evaluateCondition();

        $("#dvDDL").kendoDropDownList({
            dataTextField: "Text",
            dataValueField: "Value",
            dataSource: KM.ddlModel.cmg,
            value: value 
        });
}

Or alternatively you can set if after the drop down list is initialised if you have a reference to the drop down list, like:

myDropDownList.value(evaluateCondition());

However you cannot set the value: configuration property to a function. This is because the value of the value: property is used by assignment and it is not called like a function.