fetching via fetch/ajax gutenberg block data from third party

Question

I'm trying to use fetch to grab information from a 3rd party API which is rate-limited. Instead of doing the API on the front-end I'm trying to use fetch to do the API call in the edit function. I've seemingly have the fetch working, but I can't seem to save the data. Might someone suggest where I'm going wrong?

Attributes look like:

    attributes: {
    url: {
        type: 'string',
        selector: '.o_microlink',
        attribute: 'href',
        default: '',
    },
    title: {
        type: 'string',
        selector: '.o_microlink',
        default: '',
    },
}

Edit function looks like:

edit: props => {
    const onChangeURL = async value => {
        const response = await fetch( `https://api.microlink.io?url=${ value }`, {
            cache: 'no-cache',
            headers: {
                'user-agent': 'WP Block',
                'content-type': 'application/json'
              },
            method: 'GET', 
            redirect: 'follow', 
            referrer: 'no-referrer', 
        }).then(
            returned => {
                if (returned.ok) return returned;
                throw new Error('Network response was not ok.');
            }
        );
        let data = await response.json();
        data = data.data;

        props.setAttributes( { url: value } );
        props.setAttributes( { title: data.title} );
    };
    return <div className={ props.className }>
            <RichText
                tagName="div"
                placeholder={ __( 'Add URL here.' ) }
                value={ props.attributes.url }
                onChange={ onChangeURL }
            />
            { ! props.attributes.title ? __( 'Add URL' ) : <div> { props.attributes.title } </div> }
            </div>;
}

Save function is pretty standard:

save: props => {
    return (
        <div className={ [props.className, 'o_microlink'].join( ' ' ) }>
            <a href={ props.url}> { props.title } </a>
        </div>
    );
}

Answer 1

Well, I figured it out. Though my solution is probably far from elegant (I'm not making concessions for timeouts or usability/accessibility). My problem was mostly overzealous configuration, copy and paste errors, and needing to apply async/await keywords.

Attributes look like this:

attributes: {
    url: {
        source: 'attribute',
        type: 'string',
        selector: '.o_microlink',
        attribute: 'href',
    },
    title: {
        type: 'string',
        source: 'text',
        selector: '.o_microlink',
    }

The edit function looks like this:

edit: ({ attributes, setAttributes, className })  => {

    const onChangeURL = async value => {

        const response = await fetch( `https://api.microlink.io?url=${ value }`, {
            cache: 'no-cache',
            headers: {
                'user-agent': 'WP Block',
                'content-type': 'application/json'
              },
            method: 'GET',
            redirect: 'follow', 
            referrer: 'no-referrer', 
        })
        .then(
            returned => {
                if (returned.ok) return returned;
                throw new Error('Network response was not ok.');
            }
        );

        let data = await response.json();
        data = data.data;

        setAttributes( { url: value[0] } );
        setAttributes( { title: data.title} );
    };

    return <div className={className}>
                <RichText
                    tagName="div"
                    placeholder={__('Add URL here.')}
                    value={attributes.url}
                    onChange={onChangeURL}
                />
                {!attributes.title ? __('Add URL') : <div> {attributes.title} </div>}
             </div>;

}

The notable requirement is the async keyword on the arrow function and the two await keywords on the assignments. (I'm not catching the error here or setting the user-agent to anything useful.) The url value in onChangeURL is being set as an array of one item and I'm not sure why.

And the save function:

save: ({ attributes, className }) => {
    return <div className={ className }>
            <a className="o_microlink" href={ attributes.url }> { attributes.title } </a>
        </div>;
}

Which is pretty standard but I had put the custom class in the wrong place.