Add social sharing functionality

[kcne]

Add social network sharing to diary entry pages

Description:
This PR addresses the issue #1391 by introducing social media sharing functionality for diary entries, allowing users to share posts on platforms like Twitter, Facebook, LinkedIn, Mastodon, Telegram, and Email. It includes required JavaScript to handle opening share URLs in pop-up windows and Ruby helper methods to filter and validate allowed social media sites. The changes also incorporate error logging for invalid sites and missing icons, ensuring robustness.

Implementation details:

• lib/social_share_button_helper.rb - config, validation & helper functions
• render_social_share_buttons function inside application_helper.rb responsible for rendering the buttons with helper utilization
• social_share_button.js - javascript utility functions for opening the popups, generating urls for sharing & handling onclick events on buttons

Screenshots:

Reviews welcome,
Thank you.

[mmd-osm]

Thank you. Some of the links seem to be a bit dated, e.g. Twitter is now known as X, and links/logos would have to be updated, I suppose.

[kcne]

Updated the x icon and link as suggested by @mmd-osm. Also if you think we should include some other socials too, suggestions are welcome. Any chance @tomhughes @gravitystorm @AntonKhorev some of you guys can review this soon?
Thank you.

[talllguy]

Thanks for the hard work on this! Since we're on the topic of social sharing I thought I'd resurface an idea from 10 years ago that I still think would add value to users of the site. Perhaps the technology hurdles back then are less likely to be hurdles now. #739

[kcne]

Refactored this according to @AntonKhorev review. Please let me know If you think I can further improve this. Thank you!

[tomhughes]

Added a few comments inline... Other things to consider are whether to offer some other sites - bluesky and threads being the obvious candidates.

[kcne]

Thank you for the review!
I've resolved the requested changes, added the translations as requested, and the mailto links should now be opening correctly. Once we round this up and resolve the mastodon thing with @tomhughes I can add bluesky and threads support as a separate commit if you agree.

[kcne]

Found out there is mastodonshare.com that takes text and url query parameters and let's you choose the mastodon instance you want to share on. Updated the code accordingly. Can you please test this and let me know if this solution is okay. @mmd-osm @tomhughes

Updated mastodon link, everything should be working fine now. Can you please check and let me know if anything else can be improved. Thank you.

[kcne]

As @AntonKhorev suggested, we're now displaying these icons only when users open the full diary entry, as outlined in #5121. Since this is currently used in one place, turbo pagination issues can be handled in a future PR if a use case arises for combining it with turbo pagination. Thank you.

[AntonKhorev]

It's fine if we're ok with mastodonshare.com for now, but we can replace it later.

[tomhughes]

What is the purpose of the allow_sites option and the supporting logic that allows filtering? As far as I can tell it's tested but never actually used by any other code?

[AntonKhorev]

We can probably use it if sharing on some site requires some setting, to filter out that site if it's not set, like if we add Mastodon host preference.

[tomhughes]

Well obviously we can come up with ways to use it, like adding a configuration option to control which ones was enabled. But given that no such thing currently exists I was wondering we it had been implemented - is there some plan to make use of it in the future?

[AntonKhorev]

Merged, thanks.

Although we're effectively outsourcing Mastodon host option to mastodonshare.com, it works for anonymous users too. Currently our preferences page is not available for anonymous users but we probably should make it available and save preferences to cookies. We have other preferences like #5201 and color mode settings and we shouldn't add a button for each one.

[gravitystorm]

anonymous users

I think you mean users who are not logged in - "anonymous users" is the term we use for accounts with user.data_public == false. They are quite rare now since they haven't been permitted for a long time.

As for preferences, I'm happy keeping most preferences available for only logged in users, since account creation is free and we aim to serve our mappers (who by definition have accounts) more than just casual visitors. Storing preferences in cookies does have drawbacks (like cross-device consistency, automatic cookie expiry etc) so it's not my first choice in general.

[AntonKhorev]

I think you mean users who are not logged in

yes

As for preferences, I'm happy keeping most preferences available for only logged in users, since account creation is free and we aim to serve our mappers (who by definition have accounts) more than just casual visitors. Storing preferences in cookies does have drawbacks (like cross-device consistency, automatic cookie expiry etc) so it's not my first choice in general.

Are you against the entire idea of #1115 or just against the cookies and want preferences stored somewhere else like session? I don't think anyone who is not logged in expects cross-device consistency etc.