[Solved] Unable to process binding

Hello everyone,

I have a data-binding problem when my element (checkbox) is in the state panel.
I have an error loading the page.

Could not bind view model PrinterStateViewModel to target #state_wrapper : ReferenceError: Unable to process binding "checked: function(){return shutdown }"
Message: shutdown is not defined

in fact, I would like to add a checkbox in the state panel to manage the shutdown of the printer at the end of the print, like the plugin "Automatic Shutdown".
If I go through a template "Printershutdown_sidebar.jinja2", it works without any problem but if I move my checkbox field in the status panel, it does not work anymore.
In test, I put the code of the checkbox dirementement in the file "state.jinja2" (octoprint \ templates \ sidebar \ state.jinja2) rather than to pass by an element.before (....)

2019-02-20-13-32-40-Ender-3-Octo-Print

this code in "Printershutdown_sidebar.jinja2" works but the same in "state.jinja2" give me the error.

I repeat, if the checkbox is in its own block in the sidebar, it works.
As if changing the template checkbox, it was no longer recognized

<input type="checkbox" data-bind="checked: shutdown">

In my javascript

self.shutdown = ko.observable();

self.onshutdownEvent = function() {
 if (self.shutdown()) {
            alert("shutdown ok");
}

}
self.shutdown.subscribe(self.onshutdownEvent, self);

Thank you in advance

I found the problem, in javascript, you have to inject the element into the template and it's ok !!

  OCTOPRINT_VIEWMODELS.push({
        construct: shutdownViewModel,
        elements: [ "#shutdown-input" ]
    });
```<input type="checkbox" data-bind="checked: shutdown" id="shutdown-input">