Include one widget instead of excluding all others

Question

I have a couple of widgets in the sidebar. I do not want that some of these widgets show on some of my pages.

I do not know how to write it more simple than this? I have many exclusions, so writing it like this would be a book-work full of lines. I just want to write as simple as "on this page include only this or these widgets" (instead of "on this page exclude this and these widgets").

<%if( !(page.layout=="alpha" && (name=="w1" || name=="w2" || name=="links" || name=="w3") ) && !(page.layout=="beta" && (name=="w400" || name=="w500" || name=="w600") ) ){ %>

So question is how to make it simple that page "alpha" shows only widget895 for example?

Answer 1

I've assumed that you've got some sort of loop over the widgets and that name corresponds to the current widget name within that loop.

<%
    var pageWidgets = {
        alpha: ['widget895'],
        beta: ['widget900', 'widget123']
    };

    var allowedWidgets = pageWidgets[page.layout];

    // Loop over the widgets and grab the name, I assume
    // you're already doing something similar.
    widgets.forEach(function(widget) {
        var name = widget.name;

        // This is the equivalent of the 'if' in your
        // original code. Note that I've allowed all
        // widgets by default.
        if (!allowedWidgets || allowedWidgets.includes(name)) {
            %>
            ...widget rendering here...
            <%
        }
    });
%>