js-veb: JavaScript Value Editor Bookmarklet

editor-bookmarklet.js

(function(){
    var form = {a: 123, b: 456, c: {d: 789}};
    var d = window.open(null, "_blank").document;
    d.write('<textarea id="value" style="width:100%;height:90%;"></textarea>');
    d.write('<br><input type="button" onclick="javascript:opener.callback()" value="Changer">');
    var t = d.querySelector('#value');
    t.value = JSON.stringify(form, null, 2);
    window.callback = function() {
        form = JSON.parse(t.value);
        window.alert(JSON.stringify(form, null, 2));
    };
})();