TypeError: Cannot call method 'trim' of undefined in $translate directive

[asm89]

With the latest canary version of this module we're seeing getting TypeError: Cannot call method 'trim' of undefined errors. We've been able to track the error down to the directive when both translate and translate-values are used, but only if they're used on elements within an ng-switch (I know right 👍).

The error can be seen here: http://jsfiddle.net/uyjLS/.

After this line it is possible for the scope.translationId to be undefined: here. In master there was a check for that here. This is the commit that changed it: 3b1d1c6.

We've now fixed it locally by checking if (value && scope.translationId), but we're not sure if this is the right way to fix it and we don't know how to write an appropriate test for it. Another thing we notice is that in the "failure" case it seems that value is {}.

Hope you guys know what is happening and we're interested in seeing the actual fix so we can do it ourselves next time! :)

[knalli]

Oh well.. I had actually reviewed 4939424 but thought that could not be happened. Should be more pessimistic.

@PascalPrecht Fix both?

[0x-r4bbit]

Hey @asm89 !

First of all, thank you for the great issue! You gave us all needed information to get into this. Of course, we'll take care of that.

@knalli Do you have time to fix it?

[asm89]

@knalli I see your commit, but isn't the whole problem that it gets called with undefined?

[knalli]

yeah, but that one was the one which crashed the stuff internally and should be avoided.

@PascalPrecht I'm not sure whether the stricter condition of 08f087b will made the unwatch() still good enough. Otherwise, this should be fixed.

Actually, the bug is because value is always true (empty object). Still not ideal.

scope.$watch('interpolateParams', function (value) {

[0x-r4bbit]

@knalli if there are no interpolateParams it actually should be undefined, shouldn't it?

[knalli]

it's an empty object, actually.

[asm89]

@PascalPrecht @knalli Any news here? Any way we can help?

We also noticed the empty object, that still yields true in js, maybe that's the error?

[knalli]

Let's wait for @PascalPrecht because I'm quite not sure what the intent of the change was.

[knalli]

Okay, that was some kind of optimization. So, actually,

              scope.$watch('interpolateParams', function (value) {
                if (scope.translationId && value) {
                  iElement.html(translate(scope.translationId,  value, translateInterpolation));
                }
              }, true);

should be

              scope.$watch('interpolateParams', function (value) {
                if (scope.translationId) {
                  iElement.html(translate(scope.translationId,  value, translateInterpolation));
                }
              }, true);

because

1. !{} === false
2. Even if it is now empty, the dirty watch check means that is was prior not empty. We have to invoke the translation.

imho

[asm89]

ping @PascalPrecht

[0x-r4bbit]

Reapplied @knalli 's patch in canary.