Blogger can’t read data:post.body and data:post.url

Question

I have social sharing buttons on my blog that work normally through the expr:href="data:post.url/data:post.title" parameter that takes, respectively, the address and title of the post in question. However, I am modifying this sharing system, creating a sidebar, initially hidden (similar to the Windows 8 Harms bar) that will have the social buttons. At the end of the post, I have a visible button that when clicked calls the sidebar and exposes the share buttons.

The problem is that these buttons cannot capture the URL and title of the post through the date:post.url and the date:post.title. I didn’t change anything at the core of them, and I’ve tested those same buttons without hiding them and checked that they work normally, which made me conclude that they just don’t capture the URL and title when hidden. If they already started visible, the capture is done normally. How to proceed in this case? (detail: I hid the bar in question by setting opacity:0 in the CSS and making it visible through a button that changes the opacity to 1 and leaves it active on the screen. I didn’t use the:None display).

I thank you all for your attention. God bless! =]