Using tel: on redirector pages

[matthewalkr]

We have auxiliary navigation rails that include both links and phone numbers such as tel:0800123456 based on the RedirectorPage. This update "[SS-2017-003] Only allow HTTP(S) links for external redirector pages" breaks that and broke our web app.

In my view, limiting the schemes to HTTP and HTTPS is too restrictive. Why not allow other schemes such as TEL, and given the proliferation of schemes, why not generalise?

Here's the relevant commit

[tractorcow]

I'd be happy with allowed_schemas to be introduced to RedirectorPage, to make it user manageable. Do you feel like writing a PR for introduce this? (I suggest the 3 branch).

[matthewalkr]

Yeah I can give it a crack...Thanks for your thoughts.

[dhensby]

Whilst I'd support adding a config list of allowed schemes I'd say that using redirector pages to "redirect" to tel: links is an abuse of the RedirectorPage.

I'd urge you to either consider creating a specific page type for this or introducing a menu manager module to allow arbitrary links in menus.

[matthewalkr]

What is the imagined use case of RedirectorPage? Is it the ability to add something arbitrary to the page tree? As that's what I'm doing. Genuine question as I don't want to propose changes that are niche to my needs. I have already worked around the issue.

A menu manager would be better but there are currently none that meet our needs. I might work on that in future but time does not allow at the moment.

[dhensby]

Is it the ability to add something arbitrary to the page tree?

No, its the ability to add a page to the site tree that transparently points to another page (be it on the site or external).

A menu manager would be better but there are currently none that meet our needs. I might work on that in future but time does not allow at the moment.

I don't know what your requirements are, but https://github.com/heyday/silverstripe-menumanager is basically a menu built entirely of redirector page type objects...

[matthewalkr]

OK cheers. My position is that web pages are no different from any other legitimate URI scheme referenced here https://www.iana.org/assignments/uri-schemes/uri-schemes.xhtml#uri-schemes-1 . I don't see why SilverStripe needs to be opinionated in this matter.

Thanks for the MenuManager note. I like that app but I don't think it integrates with Translatable.

As I say, I've worked around this issue, so it's not blocking me. More a philosophical query.

[tractorcow]

Does tel: protocol get natively interpreted as "show the dialpad" on mobile devices, or other similarly useful (if strictly misuse) behaviour?

[matthewalkr]

It will actually dial the number (given a prompt first). In my view, it is the responsibility of the browser to handle the link (or not) properly.

Here's an example in the wild. On desktop, not the auxiliary menu above the main nav. This menu comprises key conversion actions. On mobile it's moved under the main nav... https://www.rainbowsprings.co.nz/

[tractorcow]

I'm in favour of updating RedirectorPage so that support for custom protocols COULD be added in. E.g. via an extension on RedirectorPage. That way the responsibility for deciding whether to follow the rules is up to usercode. :)

Perhaps a validateUrl, with an $this->extend('updateValidateUrl', $url, $valid) style approach?

[axllent]

Would this issue cover support for tel: links from within TinyMCE, or should that be opened as a separate issue? Currently the "link to external URL" from within the editor appends http:// to any tel:<nr>, possibly because they don't contain the // after the URI Scheme.

[tractorcow]

No this issue is specific to redirectorpages.