Allow setting attributes on editable inputs

[jspaine]

I think it would be nice if there was an easy way to set attributes for editable inputs without having to create a customEditor. This allows stuff like:

editable={{type: 'number', attrs: {min: 1, max: 4, step: 1}}}

I'd only want it for simple attributes, but I don't like that it just silently ignores anything the user passes for ref, onKeyDown and onBlur and I'm not sure the best way to deal with it. Is it worth the extra code to support these, should ref and on* throw an error...?

[AllenFang]

I think following will be simple, keep const and dont assign attr again:

const attr = {
      ref: 'inputRef',
      onKeyDown: this.handleKeyPress,
      onBlur: this.handleBlur,
      ...editable.attrs
};

Please check 👍 thanks

[jspaine]

Yeah that's easier 😁 I spread the user supplied attrs first though so the ref and handlers can't be overwritten.

[AllenFang]

LGTM

[jspaine]

I added the code to allow refs, keydown and blur handlers. Also a warning 'Setting editable.placeholder is deprecated. Use editable.attrs to set input attributes' so you can eventually get rid of separately setting the placeholder attr.
Does it sound ok? Shall I push it here or do you want to leave it like this?

[AllenFang]

@jspaine, it sounds good, feel free to patch PR 👍

[AllenFang]

@jspaine, this was fixed and released on v4.0.0-beta.8, thanks your contributions 👍