I have component `app-preview` which has a pushed component by it's parent into it's `ng-content`.

The code of `app-preview`s' parent : 

```
<app-preview>
      <checkbox #prv
        [indeterminate]="true"
        [checked]="true">
      </checkbox>
</app-preview>

```

I want `app-preview` not just to render, but also to save as a string into any property the template of any component which was pushed to it's `ng-content`. So I want `app-preview` to save the following string:

```
  "<checkbox #prv
    [indeterminate]="true"
    [checked]="true">
  </checkbox>"

```

into it's property and use it in it's `.ts` file. 
For example : `this.childTmpl`

How can I achieve that?

thanks