Implement in-app transitions for native anchor elements so that LinkTo isn't needed

[NullVoxPopuli]

Adds support for using solely <a> tags for in-app navigation.

Ref: emberjs/rfcs#391

Tested using: NullVoxPopuli/ember-tutorial-link-component#1

[NullVoxPopuli]

Questions:

• should we prevent a click if currently loading, like:

  ember.js/packages/@ember/-internals/glimmer/lib/components/link-to.ts

  Line 717 in 8482098

  if (this.loading) {

• should we do nothing if currently on the same route?

  ember.js/packages/@ember/-internals/glimmer/lib/components/link-to.ts

  Line 730 in 8482098

  if (!isSelf) {

• should this also used flaggedInstrument:

  ember.js/packages/@ember/-internals/glimmer/lib/components/link-to.ts

  Line 741 in 8482098

  flaggedInstrument(

• the dispatcher can have the click event disabled. Should we prevent that? or, when it's disabled, don't disable it for a tags?

[rwjblue]

@bobisjan - Mind taking a look? We were mostly fleshing this out over in adopted-ember-addons/ember-router-helpers#267 (essentially as a polyfill).

[rwjblue]

I think the same issue that was mentioned in the last comment over there is an issue here too. https://emberjs.github.io/rfcs/0391-router-helpers.html#route-globs-and-route-blacklisting

[lifeart]

should we add bad cases?

<a href="javascript:void(0)" id="loginlink">login</a>
<a href="#id-on-page">to some block</a>
<a href="#" onclick="return false;">hello</a>
<a href="backup_page_displaying_image.aspx" onclick="return coolImageDisplayFunction();">hello</a>
<a href="/robots.txt">some file</a>
<a href="blob:..." download="name">some programmatic download button</a>

in addition, if we have base (rootUrl) property for app, should we skip links upper to it? https://blog.emberjs.com/2016/04/28/baseurl

[GCheung55]

I think this is a good addition and could replace ember-href-to addon. However, this change does not allow the exclusion of links which has been very useful through ember-href-to where I am working on a project where a page is being migrated, allowing development with the same URL as the old page is still being supported.

E.g.
Production has /foo/bar served by a server.
Development app is replacing /foo/bar, which should be handled by the app.
On production, links to /foo/bar from within the Ember app is not handled as an in-app transition, allowing the old page to still be navigatable until the page is enabled/migrated.

[NullVoxPopuli]

@GCheung55 if the link isn't present in your app, it'll fallback to normal anchor behavior.

Is there something else I'm missing?

[mehulkar]

I thought I saw somewhere that the goal was to get rid of EventDispatcher?

[GCheung55]

@GCheung55 if the link isn't present in your app, it'll fallback to normal anchor behavior.

Is there something else I'm missing?

What I tried to describe is that the link DOES exist in the app but still needs to maintain normal anchor behavior as a path to a seamless migration from a non-Ember page to an Ember page.

I'll try to describe in terms of BDD:

GIVEN that a path /foo exists as a non-Ember page and an Ember page
AND a web server controls routing traffic to non-Ember pages and Ember pages
WHEN navigating to /foo, in a non-Ember page or Ember page
THEN a full page load occurs and loads the non-Ember page.

GIVEN that the web server is updated to direct /foo traffic to Ember pages
WHEN navigating to /foo, in a non-Ember page or Ember page
THEN a full page load occurs and loads the Ember page.

^ This is existing behavior that I can control with ember-href-to addon. Once the web server has been updated, the links to /foo in the Ember app are updated to be in-app navigation. The PR doesn't support this scenario described above.

[kategengler]

Is this still relevant?

[NullVoxPopuli]

it's desperately needed for DX and "using the platform"

Incorrect link, because I thought this was something else

it's a feature that's desperately needed, else hacks get implemented:
https://github.com/CrowdStrike/ember-url-hash-polyfill/blob/main/addon/index.ts

But maybe a new Polaris router would do this for us somehow?

[kategengler]

You have an open issue to amend an RFC, so I wasn't sure if this particular implementation was still relevant.

[NullVoxPopuli]

so I wasn't sure if this particular implementation was still relevant.

I am not sure, but also, I implemented this in userland here:

https://ember-primitives.pages.dev/4-routing/proper-links

Hopefully the new router can have this built in.