Trying to unravel the mystery of field binding

I'm dynamically creating a form based on info loaded from a json file. I've tried everything I can think of to get a value loaded from the json to display in a widget but nothing I've tried works.
The documentation regarding binding is (in my opinion) a bit opaque.
(forgive me if binding is not the right functionality - it just seemed to be what I was looking for)

This is the last obstacle I have to overcome before using forms in production.
Could someone show me the error of my ways? Thanks in advance.

To summarize: As I build the form, I have a value that I want to insert into the form input element that will be visible when the page is rendered.

```
/* configObject is an object parsed from json I load from a file

each itemElement below contains:
{
"value": ,
"type": ,
"length":
}

//formObject[itemIndex].bind(itemElement.value); // no error but nothing happens
//formObject.bind({itemIndex: itemElement.value}); // error: formObject has no method 'bind' });
```