I wrote this to automate somewhat the task of moving some WordPress data to a new install. Didn't have Administrative permissions or server access so had to manually copy and paste. This method made it a lot faster. One script generates a payload and the other uses that payload to fill the form fields.

generate.js

// GENERATE
function getScript(url, callback) {

    var head = document.documentElement,
        script = document.createElement('script'),
        done = false;

    script.src = url;

    script.onload = script.onreadystatechange = function() {

        if(!done && (!this.readyState || this.readyState === 'loaded' || this.readyState === 'complete')) {

            done = true;

            if(callback !== undefined) {

                callback();
            }

            script.onload = script.onreadystatechange = null;
            if(head && script.parentNode) {

                head.removeChild(script);
            }
        }
    };

    head.insertBefore(script, head.firstChild);

    return undefined;
}
// Get jQuery
getScript('https://ajax.googleapis.com/ajax/libs/jquery/2.0.0/jquery.min.js', function() {
    $('[name="lolfmkbox_portfolio_type"]').attr('id', 'lolfmkbox_portfolio_type');
    var fieldIds = [
        'title',
        'content',
        'lolfmkbox_portfolio_type',
        'lolfmkbox_gallery_shortcode',
        'lolfmkbox_portfolio_desc',
        'lolfmkbox_portfolio_date',
        'lolfmkbox_portfolio_date_label',
        'lolfmkbox_portfolio_client',
        'lolfmkbox_portfolio_client_label',
        'lolfmkbox_portfolio_skills',
        'lolfmkbox_portfolio_skills_label',
        'lolfmkbox_portfolio_url',
        'lolfmkbox_portfolio_url_label',
        'slide_template',
        'yoast_wpseo_focuskw',
        'yoast_wpseo_title',
        'yoast_wpseo_metadesc'
    ];
    var fields = {};
    for (var i in fieldIds) {
        fields[fieldIds[i]] = $('#' + fieldIds[i]).val();
    }

    var tags = [];
    $('.tagchecklist span').each(function() {
        $(this).find('a').remove();
        tags.push($(this).text());
    });
    fields['new-tag-portfolio-categories'] = tags.join(',');

    console.log(JSON.stringify(fields));
});

populate.js

// POPULATE
function getScript(url, callback) {

    var head = document.documentElement,
        script = document.createElement('script'),
        done = false;

    script.src = url;

    script.onload = script.onreadystatechange = function() {

        if(!done && (!this.readyState || this.readyState === 'loaded' || this.readyState === 'complete')) {

            done = true;

            if(callback !== undefined) {

                callback();
            }

            script.onload = script.onreadystatechange = null;
            if(head && script.parentNode) {

                head.removeChild(script);
            }
        }
    };

    head.insertBefore(script, head.firstChild);

    return undefined;
}
// Get jQuery
getScript('https://ajax.googleapis.com/ajax/libs/jquery/2.0.0/jquery.min.js', function() {
    // Add ID for type
    $('[name="lolfmkbox_portfolio_type"]').attr('id', 'lolfmkbox_portfolio_type');

    // Loop and set values
    for (var i in d) {
        if (i == 'content') {
            console.log('setting content', d[i]);
            tinyMCE.activeEditor.setContent(d[i]);
        } else {
            console.log('find #' + i + ' and set to ' + d[i]);
            $('body').find('#' + i).val(d[i]);
        }
    }

    $('#lolfmkbox_portfolio_type').change();
});