Handle missing values in Preview for Metadata component

[Simply007]

Motivation

As was described in #115, there is insufficient check for missing values for Metadata component values.

Great jop @Karl-EdwardFPJeanMehu, thanks!

Proposed solution

According to the metadata (i.e. ogImage) I would recommend using the lodash for the value check:

import _ from 'lodash';
...
      {!_.has(props, 'ogImage.value[0].url') ? null : (  // current state =>  {!props.ogImage ? null : (
        <meta property=\"og:image\" content={props.ogImage.value[0].url} />
      )}

[Karl-EdwardFPJeanMehu]

I'm interested.

[petrsvihlik]

Hi @Karl-EdwardFPJeanMehu , I've just sent you an invitation to the project. I'll be able to assign the issue to you once you accept it.