 Hello everyone, I am Sarper Akdemir and I am an internet collaborator. In this lightning talk, I will be talking about some hacking I did around PPTX footer interoperability. Let's start by talking what was there to fix. Export of footers wasn't there for PPTX at all. This meant instant data loss for any user that saved to PPTX. Also, a footer imported from PPTX was imported directly as a textbox. Impress didn't recognize it as a footer. Although this caused no data loss, I thought tackling this mattered since when a user saves to PPTX and reopens the file, although it is not advised to do so as a workflow, there would be no footers anymore. They would just become textboxes. And the user just can't manipulate the footers in batches anymore, which I believe the main selling point of the footers in presentations. It is important to note here that it is technically not quite possible to always import footers from PPTX into Impress as footers. Since in PPTX, it is possible to style a footer differently than its master. And this is just not possible on ODP or Impress, which inherits all footer-related styles from the master. So what was the fix? The import problem was the first one I tackled. Main challenge here was differentiating whether a footer had some additional formatting applied to it that the master placeholder didn't have. If it inherited all the changes from the master and there was not an additional, it was imported as a slide property, meaning a standard Impress footer. If it had some additional styling, etc., it just fallbacks to the previous implementation and gets imported as a textbox. To clarify, before the import fix, after footers were imported from a PPTX file with footers, none of these boxes were checked. The footers were there, but Impress didn't knew they were indeed footers. And after the fix, we can successfully get the footers as Impress understands them. After I was happy with the import, I started to work on the export fix. To make the export work and make it run through possible, I had to implement export of placeholder index to reference placeholders. This is how normally placeholders are referenced on PPTX. A shape from the slide has a placeholder index which references the layout placeholder. And the layout has another placeholder index that references the master placeholder. This is the mechanism PPTX uses to inherit styles from the correct placeholder. And it inherits these styles from the LSD styles tag of the placeholder it references. There was no export of LSD styles nor placeholder index implemented. So I implemented some basic versions of bot that covers the problem with footers. After getting those ready, making as export of the footers work were relatively easy. With import and export of the footers done, now saving to PPTX and reopening the PPTX file to work on it will hopefully create less friction. And users will find their footers as they expected to find them. Also, while I'm at it, I try to improve the datetime conversion a little. Refactored some code there and there were some objectively better mappings for some datetime formats so I changed them. Before ending the talk, let me talk about what's left or what could be improved. Right now the implementation only covers slide footers. It does not include export of notes or handout page footers. Including those should hopefully be straightforward. Also, there's a regression. It appears that this happens since there's no lang tag specified on export. Thanks a lot, Cisco, for pointing this out. This is in my radar and I'll fix it soon. One last thing to improve could be using the LSD styles for all placeholders on export. I think this might result in better interoperability. So, that's all from me. Thank you all for listening to my lightning talk. I wish you all a happy conference. Cheers, bye-bye.