Translation helper ({{t}} doesn't accept SafeString as argument

[MiLaSen]

Issue Summary

Using SafeString as key for theme translation helper throws warning: "Theme translations {{t}} helper called without a translation key."
It is not possible, for example, to use result of concat helper as key for translation.

Steps to Reproduce

Code:
```
{{#with (concat "dog" "and" "cat" separator=" ") as |Key|}}
{{log (Key)}}
{{t (Key)}}
{{/with}}

### Ghost Version

6.10.3

### Node.js Version

22.13.1

### How did you install Ghost?

MacOS 13.7.8, install command: 'ghost install local'

### Database type

SQLite3

### Browser & OS version

_No response_

### Relevant log / error output

```shell
SafeString { string: 'dog and cat' }
[2025-12-21 10:01:55] WARN Theme translations {{t}} helper called without a translation key.

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🔗 Similar Issues

Related Issues

• Quirky triple-stash ({{{ }}} ) behavior with titles #21472
• Excerpt not pulling entire HTML entity #21955
• {{ghost_head}} and accents #21999

👤 Suggested Assignees

• cathysarisky
• brandishwar

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[MiLaSen]

My workaround:
Adding new "simpleString" option for concat helper:

// core/frontend/helpers/concat.js

const { SafeString } = require('../services/handlebars');

module.exports = function concat(...args) {
    const options = args.pop();
    const separator = options.hash.separator || '';
    const simpleString = options.hash.simpleString || false;

    // Flatten arrays - if an argument is an array, spread its elements
    const flattenedArgs = args.flat();

    if (simpleString === true) {
        return (flattenedArgs.join(separator));
    }
    else {
        return new SafeString(flattenedArgs.join(separator));
    }
};

Usage:

{{#with (concat "dog" "and" "cat" separator=" " simpleString=true) as |Key|}}
  {{log (Key)}}
  {{t (Key)}}
  {{log (t (Key))}}
{{/with}}

// /locales/sk.json
{
    "dog and cat":"pes a mačka"
}

As expected, no warning in console, translator helper works.

shell output:

dog and cat
pes a mačka

[cathysarisky]

Ghost doesn't list #with as a supported helper, so I'm actually a little surprised that works!

[vikaspotluri123]

{{#with}} is a built-in handlebars helper - Ghost gets it by default!

@MiLaSen Can you share a more specific use case for needing to support SafeStrings? @cathysarisky is working on migrating the theme translation infrastructure to use i18next, which doesn't play well with dynamic translation strings. You can use substitutions (Your email ({email}) will get notifications), but concatenated strings won't get extracted properly.

[cathysarisky]

So this does not validate with gscan and can't be activated, FYI:

{{#with (concat "dog" "and" "cat" separator=" ") as |Key|}}
{{log (Key)}}
{{t (Key)}}
{{/with}}

(I'm guessing you probably activated the theme and then edited the file?)

If you're not yet using the i18next theme translation (currently in private beta), here's a workaround that works right now:

{{#with (concat "dog" "and" "cat" separator=" ") as |Key|}}
{{#foreach Key }}{{t this}}{{/foreach}}
{{/with}}

If you are using the new i18next theme translation, then this will work:

{{#with (concat "dog" "and" "cat" separator=" ") as |Key|}}
{{t Key}}
{{/with}}

(Note lack of parens in {{t Key}} )

If you're self hosting and would like to enable the private beta now, directions are here: https://forum.ghost.org/t/anyone-interested-in-translating-an-official-theme/48560/38

And congrats! I thought I had a 100% identical drop-in, but you found an edge case. :) (Since it's a case of the i18next package being more tolerant, I'm not going to worry about it.)

To @vikaspotluri123 's comment about string extraction: Agreed, string extraction isn't going to work correctly for programmatically created strings, but I've definitely had times where I could enumerate the possibilities for string concatenation, and just manually add the strings. (Or put them in a never-used partial, to cause string extraction to pick them up.) Problems with string extraction don't have to mean problems with string translation.

Since the theme translation implementation in beta does take SafeStrings and there's a workaround until it's generally available, I'll suggest that @MiLaSen could probably close this bug. :)

[MiLaSen]

Many thanks @cathysarisky ! My goal was to get (in whatever way) dynamically created strings into the translator helper - and it definitely works with your approach. And also thanks for the hint about activating beta with i18next – I couldn't find it (I probably didn't search very well), so I'll try it out now.

If you're not yet using the i18next theme translation (currently in private beta), here's a workaround that works right now:

{{#with (concat "dog" "and" "cat" separator=" ") as |Key|}}
{{#foreach Key }}{{t this}}{{/foreach}}
{{/with}}

If you are using the new i18next theme translation, then this will work:

{{#with (concat "dog" "and" "cat" separator=" ") as |Key|}}
{{t Key}}
{{/with}}

(Note lack of parens in {{t Key}} )

If you're self hosting and would like to enable the private beta now, directions are here: https://forum.ghost.org/t/anyone-interested-in-translating-an-official-theme/48560/38

And congrats! I thought I had a 100% identical drop-in, but you found an edge case. :) (Since it's a case of the i18next package being more tolerant, I'm not going to worry about it.)

:)

I'm closing it now.