Scroll to Top of Topic instead of Reloading

[verg]

This PR changes the following links to use URLs with the first post rather than the topic url:

1. Clicking a Topic's header.
2. Quotes and Replies to the first post.
3. Jump to Top button in the Progress Bar.

For example. We'll now link to /t/discourse-general-polish/13184/1/ instead of than /t/discourse-general-polish/13184. This loads the topic much more quickly than the full page reload.

From: https://meta.discourse.org/t/discourse-general-polish/13184

We unconditionally reload topic page if you click on "title". instead it should scroll you to top if post 0 is already in memory. Same for in between posts navigation (eg quoting and so on)

[discoursebot]

You've signed the CLA, verg. Thank you! This pull request is ready for review.

[coding-horror]

This means copying the link from the topic header is now deep linking to the first post -- that's not desirable.

Cases 2 and 3 in your list are probably OK though since they aren't such obvious click-copy targets.

[riking]

Why not call the jumpTop method in the file below this?

[verg]

Is it normal to call functions on other controllers? That feels odd to me.

[verg]

@coding-horror Do you think something like this would work?

<a class='topic-link' href='{{unbound topic.url}}' {{action jumpToTopPost}}>{{{topic.fancy_title}}}</a>

Enter the Topic url in the href, but link to an action that loads the first post. I just tested it out in my dev and it works functionally.

[coding-horror]

provided right-click copy of the URL in the topic header returns the root URL, with no /1 on it, that should be OK. We usually test in Safari, IE10+, FF, Chrome.

[SamSaffron]

@verg yes that is far preferable we can not give up right click, also ... please test cases where posts are not loaded (eg: very long topic)

[verg]

Great. Thanks! I updated the PR so the title links have the topic-level href. Looks good on Safari/IE/FF/Chrome and on long topics.

[SamSaffron]

OK, trying this out! thanks!