WordPress gutenberg block – jquery generated content not saved

I am new to WordPress Gutenberg blocks. I created a gallery plugin and I want a user to be able to insert gallery shortcode by simply choosing the desired gallery from a popup window. I use jQuery text() function to inject shortcodes from the popup window with success but the content will not be saved. However, when I type in some text everything works fine.

Here is my Gutenberg js:

var el = wp.element.createElement,
registerBlockType = wp.blocks.registerBlockType,
RichText = wp.editor.RichText,
blockStyle = { backgroundColor: '#0000cc', color: '#fff', padding: '1%', margin: '1%', border: 'none', boxShadow: '5px 5px 5px #000', cursor: 'pointer' };

registerBlockType( 'prtxgal/block', {
    title: 'Protex gallery',

    icon: 'images-alt',

    category: 'common',

    attributes: {
        content: {
            type: 'string',
            source: 'html',
            selector: 'div',
        }
    },

    edit: function(props) {
        var content = props.attributes.content;

        function onChangeContent( newContent ) {
            props.setAttributes( { content: newContent } );
        }

        return[ el(
            'button', { className: 'button add_prtxgal', /*style: blockStyle*/}, 'Choose gallery'
            ),
            el (RichText,
            {
                tagName: 'div',
                className: props.className,
                onChange: onChangeContent,
                value: content,
            }
            ),
        ];
    },

    save: function(props) {
        var content = props.attributes.content;

        return el( RichText.Content, {
            tagName: 'div',
            className: props.className,
            value: content
        });
    },
});