Inconsistency in ng-bind and interpolate

[just-boris]

Here is example:
http://plnkr.co/edit/C95zazjXx5jfDrMqIE67?p=preview
Same data gives diffrerent output in interpolate and ng-bind

ng-bind: [object Object]
interpolate {"a":1,"b":2,"c":3}

I expected that ng-bind will render the same result that interpolate does.

[mhartington]

From my understanding, ng-bind is used internally for $interpolate to convert the data in to a string.

So in your example, ng-bind is pulling in the raw object, which is not converted to a string.
With {{data}} we're essentially saying bind to the raw data object and print it out a string.

Hope this helps a little bit

http://jsbin.com/jedete/5/edit?js,console,output

[gkalpak]

I am not really sure what @mhartington means, but I don't think ngBind is used by $interpolate. The difference is thatngBindassigns a value toelement.textValue(which implicitly converts the value to a string; and callingsomeObj.toString()returns[object Object]). $interpolate` on the other hand uses a custom "stringify" function that converts objects to JSON.

This merely confirms what OP already pointed out: that the behaviour of ngBind is different from that of $interpolate.
I am not sure why that is, but note that (a) $interpolate is not exclusively used in the view and (b) they shouldn't necessarily behave the same.

[just-boris]

So, there is few thoughts:

• Difference in behaviour should be noted in documentation. Now there is just said that "is similar but less verbose".
• I need a directive version for interpolate behaviour. Now I can write a custom one, but why not to include it in the core.

[pkozlowski-opensource]

@gkalpak would there be any reason for:

they shouldn't necessarily behave the same.

Honestly I'm not sure we've got this inconsistency and I can't think of any reason.

[gkalpak]

@pkozlowski-opensource: There might some reasons (for the nconsistency); but I wouldn't know.
I can't think of any either.

Changing $interpolate or text-interpolation would be too much of a breaking change though.
Chanigng ngBind to make it consistent with interpolation wouldn't hurt I guess (unless someone is relying on getting [object Object] back or passing very large objects to ngBind).

[pkozlowski-opensource]

Right, I was thinking of eventually having ngBind following the logic of $interpolate

[lgalfaso]

This looks like a valid issue and I have to agree that ngBind should follow the same logic that $interpolate has. Doing this without code duplication might turn to be a patch larger than expected, but given that it is a small breaking change, it would be ideal that if a fix lands, that it would be before we cut 1.4

@petebacondarwin WDYT?

[petebacondarwin]

I agree that we should fix ngBind. I would prefer to prioritize fixing regressions for 1.4.0 before we make this change though. It is fairly low priority given that one can always work around it by writing a directive.
Also one can use ngBindTemplate too to get the same result.

[petebacondarwin]

Actually I think this would be pretty straightforward. Just extract the stringify function from the $interpolate service factory and change the ngBind watch handler to:

        scope.$watch(attr.ngBind, function ngBindWatchAction(value) {
          element.textContent = stringify(value);
        });

[alexey-sh]

small crutch:

ng-bind="data|json"

[gkalpak]

@alexey-sh: The output is not exactly the same (this is more visible in elements that preserve whitespace; such as <pre>).
As @petebacondarwin already mentioned, ngBindTemplate="{{...}}" can be used (as a temporary workaround).

Updated plnkr