RFC: Themes available from a token into URLs

[cara-tm]

Is your feature request related to a problem?

No!

What is the feature?

I don't know if it's possible: it will be very useful to have a kind of token added into the URL to serve a definite theme (maybe governed via "Preferences"). That feature could allow anybody to test a new website model (for clients, for online tools, for SmartPhones checking, etc.)

[Bloke]

I'm confused. Setting a dev theme automatically shows the in-dev experience to anyone logged in. Usually, letting your client have a managing editor login allows them to see what's going on, and they can sign the changes off ready for go-live. If they sign in on different devices, that's the experience they see.

So you want some URL param to deliver the in-dev experience without being logged in?

[phiw13]

@Bloke —Use case: I am (or the client / stakeholder / … is) logged in on a desktop computer and want to view the result on a small screen device. All the while editing the page(s) (text/element placement/design/…).

[Bloke]

@phiw13 Yeah, that would be more handy than having to log in on a second device, which kicks you out of the desktop. I usually get round it with a pair of accounts. Not ideal.

I can't think of a simple way to do this, besides assigning each theme some unique hash (somehow) so you can tack that onto the URL and have it render the dev theme instead of the live one. It would have to be something unguessable, otherwise anybody could potentially see it.

[cara-tm]

@Bloke

No worries. Just an idea. The reason why I said I don't think it's possible.

[jools-r]

The reason why I said I don't think it's possible.

@cara-tm Not necessarily the answer you are looking for, but might you be able to leverage parse_page() in combination with gps to do that?

Make yourself a temporary page template that serves as a switcher: it checks for your url variable and outputs either your new or old page_template. Something like this (untested):

<txp:php>
    if (gps('show') == 'new') {
        echo parse_page('template_name', 'newtheme');
    } else {
        echo parse_page('template_name', 'oldtheme');
    }
</txp:php>

Set that as your section's page template and then call https://www.yoursite.com/section-name/?show=new to see the new version. For easier surfing, save the setting to the browser's localstorage and check for that too (you'll then need a reset option to get back to the old template).

BTW: the PHPdoc function example here is lacking a value for 'theme'.

---

Aside: I sometimes use this method to route a page template through to another, e.g. error_401 -> error_default (for example, incorrectly answering a password_protect tag in debug mode causes the tag with password to show in the error notice! Adding an own error_401 template silences that. Using the following avoids you having to duplicate the whole template:

<txp:php>
    // Use the same page as error_default
    echo parse_page('error_default','');
</txp:php>

[cara-tm]

I tried but it doesn't seem to work...