javascript函数中的可选参数

Question

I have a common function:

function getUrl() { return Xrm.Page.context.getClientUrl() + "/api/data/v9.0/"; }

But sometimes I need to use parent frame to get url, like this:

function getUrl() { return window.parent.Xrm.Page.context.getClientUrl() + "/api/data/v9.0/"; }

Can I declare this common function with possibility to pass window.parent. if I need it? And if the parameter is not passed, use the common implementation.

Answer 1

Just use a param:

function getUrl(_use_parent){
    let url;
    if(_use_parent)
       url = window.parent.Xrm.Page.context.getClientUrl();
    else 
       url = Xrm.Page.context.getClientUrl();

    return url + "/api/data/v9.0/";
}

If you just call getUrl(), _use_parent is undefined so it use the else statement.

[edit] And if you really want to pass window.parent

function getUrl(_window_parent){
    let url;
    if(_window_parent)
       url = _window_parent.Xrm.Page.context.getClientUrl();
    else 
       url = Xrm.Page.context.getClientUrl();

    return url + "/api/data/v9.0/";
}

But if _window_parent isn't the correct object you could get a JavaScript error.