如何在SAPUI5 Controller中实现基于if / else的功能？

Question

I am trying to do an if/else based on the checkbox flag. Below are snippets of my view and controller. I am getting a syntax error on the last but one line. Anyone has any clue?

View-

<mvc1:View
   controllerName="sap.ui.demo.wt.controller.App"
   xmlns="sap.m"
   xmlns:mvc1="sap.ui.core.mvc1">

<CheckBox id="i1" text="Test" selected="false" select ="checkDone" enabled="true" />

</mvc1:View>

Controller-

sap.ui.define(["sap/ui/core/mvc/Controller"], function(Controller) {
    "use strict";
    return Controller.extend("sap.ui.demo.wt.controller.App", {
        checkdone: function() {
            var check = this.byId("i1").getSelected();
            if (check = true) {
                alert("Successful");
            } else {
                return '';
            }
        }
    })
};);

Answer 1

I assume that you need to remove return '' line.

Moreover, I would advice you to use if (check === true) or if (check) plus it seems to be more beneficial if you get selected checkbox by

checkDone: function (oEvent) {
     var bSelected = oEvent.getParameter('selected'));
}

If these hints don't help, check semicolons and brackets. In general every IDE should advice you something if it is wrong. I think that end of your controller should be like this:

            } else {
                return '';
            }
        }
    });
});

Answer 2

I have noticed some of the things in your code,

Get the event in checkdone method and try to get the selected data from that event instead of id.

While comparing with the true use === instead of = .

And in the last you are using the semicolon in the wrong places. So thats why you are getting the errors.

sap.ui.define(["sap/ui/core/mvc/Controller"], function (Controller) {
    "use strict";
    return Controller.extend("sap.ui.demo.wt.controller.App", {
        checkdone: function(oEvent){
            var check = oEvent.getParameter('selected');
            if (check === true){
                alert("Successful");
            } else {
                return '';
            }
        }
   });
});

Answer 3

As per your code you have used extra semicolon in last line

 sap.ui.define([ "sap/ui/core/mvc/Controller" ], function(Controller) {
     "use strict";
     return Controller.extend("sap.ui.demo.wt.controller.App", {
         checkdone: function() {
             var check = this.byId("i1").getSelected();
             if (check = true) {
                 alert("Successful");
             } else {
                 return '';
             }
         }
     })
 };);//extra semicolon 

Updated code:

sap.ui.define(["sap/ui/core/mvc/Controller"], function(Controller) {
    "use strict";
    return Controller.extend("sap.ui.demo.wt.controller.App", {
        checkdone: function() {
            var check = this.byId("i1").getSelected();
            if (check) {
                alert("Successful");
            } else {
                return '';
            }
        }
    })
});//remove exta semicolon