# Observable casting bug

**URL:** <https://forums.fusetools.com/t/observable-casting-bug/5366>\
**Category:** Bug Reports\
**Created:** [December 27, 2015, 12:11pm UTC](https://forums.fusetools.com/t/observable-casting-bug/5366 "2015-12-27T12:11:01Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Bjorn-Olav\_Strand](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/bjorn-olav_strand/32/583_2.png) [@Bjorn-Olav\_Strand](https://forums.fusetools.com/u/Bjorn-Olav_Strand)\
**Post date:** [December 27, 2015, 12:11pm UTC](https://forums.fusetools.com/t/observable-casting-bug/5366/1 "2015-12-27T12:11:01Z")

</div>

```auto
<App Theme="Basic">
    <JavaScript>
        var Observable = require('FuseJS/Observable');
        var obs = Observable(false);
        module.exports.obs = obs;
    </JavaScript>
    <StackPanel>
        <WhileTrue Value="{obs}">
            <DebugAction Message="WhileTrue: true" />
        </WhileTrue>
        <Button Text="{obs}" />
    </StackPanel>
</App>

```

Gives:

```auto
ERROR: Unable to convert False to bool
    System.Exception occured.
      at Fuse.Reactive.Marshal.ToBool (System.Object obj) [0x00000] in <filename unknown>:0 
      at Fuse.Reactive.Marshal.ToType[Boolean] (System.Object o, System.Action1 callback) [0x00000] in &lt;filename unknown&gt;:0 
      at Fuse.Reactive.DataBinding1[System.Boolean].PushValue (System.Object newValue) [0x00000] in <filename unknown>:0 
      at Fuse.Reactive.DataBinding1[System.Boolean].Fuse.Reactive.IObserver.OnSet (System.Object newValue) [0x00000] in &lt;filename unknown&gt;:0 
      at Fuse.Reactive.Dispatcher+ArgDispatch1[System.Object].Run () [0x00000] in <filename unknown>:0 
      at Fuse.Reactive.Dispatcher+UIThreadDispatcher.Run () [0x00000] in <filename unknown>:0 
      at Fuse.UpdateListener.Invoke () [0x00000] in <filename unknown>:0 
      at Fuse.UpdateManager.Update (Fuse.Stage stage) [0x00000] in <filename unknown>:0

```

```auto
$ fuse --version
Fuse version 0.9.5 (build 5424)
Copyright (C) 2015 Fusetools

```

Fuse Local Preview.

---

<div class="post-metadata">

**Author:** ![Anders\_Lassen](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/anders_lassen/32/522_2.png) [@Anders\_Lassen](https://forums.fusetools.com/u/Anders_Lassen)\
**Post date:** [December 27, 2015, 12:12pm UTC](https://forums.fusetools.com/t/observable-casting-bug/5366/2 "2015-12-27T12:12:19Z")

</div>

Thanks for the simple test case. On it!

---

<div class="post-metadata">

**Author:** ![Anders\_Lassen](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/anders_lassen/32/522_2.png) [@Anders\_Lassen](https://forums.fusetools.com/u/Anders_Lassen)\
**Post date:** [December 28, 2015, 2:05pm UTC](https://forums.fusetools.com/t/observable-casting-bug/5366/3 "2015-12-28T14:05:18Z")

</div>

Fixed. Will roll out soon 🙂