Support for GTM environments

[boter3]

Would it be possible to add support for GTM environments for easier development / staging testing?

Unfortunatelly the GTM id is same for all environments, they are separated by &gtm_preview=env-6 attribute.

GTM > Admin > Environments

[jissereitsma]

Sure, this sounds like a great idea.

What needs to be done to make this work?

[boter3]

I am hardcoding / overriding this string into:
vendor/yireo/magento2-googletagmanager2/view/frontend/templates/iframe.phtml
vendor/yireo/magento2-googletagmanager2/view/frontend/templates/script.phtml

And this is AI generated (sorry) proposition:

Proposition: Support GTM Environment Preview (optional query string)
Use case
Google Tag Manager supports Environments (e.g. “Staging”, “Development”). To load a specific environment, the gtm.js and ns.html URLs must include extra query parameters that GTM provides in the container snippet, for example:
gtm_preview=env-6
gtm_auth=
gtm_cookies_win=x
Right now the module builds the script URL without any query string, so environment preview only works if the user adds these params to the page URL (Preview link from GTM). Many teams want to force a given environment per store (e.g. staging site → env-6) without theme overrides or hardcoded strings.
Suggested approach (minimal, non-breaking)

1. New optional config field
   Path: googletagmanager2/settings/ (same group as “Container Public ID”, “Debug”, etc.).
   Suggested ID: environment_query_string (or preview_params).
   Type: textarea or text.
   Behaviour: Optional. When empty, behaviour is unchanged (no query string). When set, the value is appended to both the gtm.js and ns.html URLs.
   Comment for the field (for merchants):
   “Optional. For GTM Environment Preview: in GTM go to Admin → Environments → [your environment] → Get Snippet, then paste only the query string part (e.g. &gtm_auth=xxx&gtm_preview=env-6&gtm_cookies_win=x). Leave empty for the default/live container.”
2. Config class
   Add a getter that returns the raw value (or empty string), so templates stay simple:
   /** * Optional query string for GTM Environment Preview (e.g. &gtm_auth=...&gtm_preview=env-6&gtm_cookies_win=x). * When set, appended to gtm.js and ns.html URLs. Empty = use default container. * * @return string */public function getEnvironmentQueryString(): string{ return trim((string) $this->getModuleConfigValue('environment_query_string', ''));}
3. Templates
   script.phtml: when building j.src, if getEnvironmentQueryString() is non-empty, append it (with a leading & if the stored value doesn’t start with &).
   iframe.phtml: when building the ns.html URL, append the same string the same way.
   So the change is: one new config key, one new method, and two small template edits. No change for existing installs (default remains empty).
   Why a single “query string” field
   GTM’s snippet is a single query string; merchants can copy it in one go from the GTM UI.
   Avoids multiple fields and parsing; no need to validate or explain each parameter.
   Easy to clear (empty = live container) and to switch between environments by pasting a different snippet.
   References
   GTM Help: Use environments to test container changes
   Snippet format: when you choose an environment and “Get Snippet”, the script URL ends with ?...&gtm_auth=...&gtm_preview=env-X&gtm_cookies_win=x. That query part is what would be stored in environment_query_string.
   Summary
   Ask: Add an optional config field (e.g. environment_query_string) and a getEnvironmentQueryString() (or similar) method; when non-empty, append this string to both the gtm.js and ns.html URLs so GTM environment preview works without theme overrides or hardcoded strings.