I have created a custom banner image block for Gutenberg, which works great, but
I want to know if it is possible to use the page title as the current banner text
placeholder until it has been edited?

My Edit function is

 return [
            el('div', {className:'header-banner'},
                el(
                    element.Fragment,
                    null,
                    controls,
                    el( "div",{
                        className: 'banner-image',
                        style: { backgroundImage: 'url('+attributes.mediaURL+')' }
                    },
                    attributes.title || isSelected ?  el(RichText, {
                            key: 'editable',
                            tagName: "h1",
                            className: "banner-title",
                            //Can i add the page title in here if it is avaiable??
                            //placeholder: i18n.__('Write title…'),
                            value: attributes.title,
                            onChange: function onChange(value) {
                                return props.setAttributes({ title: value });
                            },
                            inlineToolbar: true
                        }) : null 

                    )
                )
            )//header-banner
        ];    

Thanks 🙂