New feature/66 browser native dataset file preview

[luistoptal]

Pull request for issue: #66

This PR adds a preview modal for the dataset table, eg http://gigadb.gigasciencejournal.com/dataset/100094

The video shows a handful of cases
Screencast from 10-01-25 16:20:33.webm

• images are displayed as simple img elements
• text files, pdf and html are displayed within an iframe using the native browser behavior
• other types are filtered out and the preview button is greyed out and disabled

How to test?

In http://gigadb.gigasciencejournal.com/adminFile/create you can add any arbitrary files via their url to any dataset to test the modal, eg
https://s2.q4cdn.com/175719177/files/doc_presentations/Placeholder-PDF.pdf
https://images.pexels.com/photos/378570/pexels-photo-378570.jpeg
http://gigadb.gigasciencejournal.com/
https://raw.githubusercontent.com/gigascience/gigadb-website/refs/heads/develop/README.md
etc

How have functionalities been implemented?

• added a button to the protected/views/dataset/view.php that opens a modal to preview the file

• if the file is "not supported" the preview button is disabled. What is supported is defined by protected/views/dataset/view.php:417
  

• protected/views/dataset/_preview_modal.php contains the code related to the preview modal. At the core, there is a conditional that determines what to do for each file type:

  • image: render a element
  • files of type TEXT, HTML and PDF: render an iframe pointing to the image location
  • anything else renders a "unsupported" message.

• this kind of structure is built to be easily extendable by adding more valid cases

• I have also renamed the id of a preexisting modal to something more meaningful

Any issues with implementation?

--

Any changes to automated tests?

Added acceptance test that checks for the presence of the preview button and that it toggles a preview modal