Error when using Handlebars.compile

[epochslee]

I use Handlebars.compile to render the template for sending emails. When I use compile I the following error:

this.__ is not a function

Which I believe comes from the helper.

[kaywolter]

Can you please provide a minimal setup which reproduces the error?

[epochslee]

Here the function that compiles the text to use in an email.

const {
    promisify
} = require('util');

const fs = require('fs');
const Handlebars = require('Handlebars');
const readFileAsync = promisify(fs.readFile);

const mailerGet = {
    method: 'GET',
    path: '/mailer',
    handler: async () => {

        let compiledTemplate = null;
        const content = (await readFileAsync('./templates/velocityNotification.hbs')).toString();
        compiledTemplate = Handlebars.compile(content);
        const body = compiledTemplate({
            name: 'John Doe'
        });
        console.log(`body: ${body}`);
    }
};

This is the Handlebars template I use to compile the body of the email. I have tried both {{{__ and {{#i18n to use the helper.

<div style='padding: 20px'>
    <div style='padding: 10px'>
        {{{__ "Thank you, %s, for starting the process." name}}}
    </div>
</div>

I have this in my helper

Handlebars.registerHelper('i18n', function (context) {

    return this.__(context);
});

[kaywolter]

Can you pls create a repository or zip file that I can use to reproduce the error? I'm not really confident in setting up Handlebars. Would be helpful if I only need to run npm install and npm start.

[epochslee]

emailer_test.zip

Run npm install navigate to localhost:3050/emailer

You will see the error catch in the try/catch printed in the logs:

{ Error: Missing helper: "__mf" at Object.<anonymous> (/Users/user/git/node/emailer_test/node_modules/Handlebars/dist/cjs/handlebars/helpers/helper-missing.js:19:13) at Object.eval [as main] (eval at createFunctionContext (/Users/user/git/node/emailer_test/node_modules/Handlebars/dist/cjs/handlebars/compiler/javascript-compiler.js:257:23), <anonymous>:6:85) at main (/Users/user/git/node/emailer_test/node_modules/Handlebars/dist/cjs/handlebars/runtime.js:175:32) at ret (/Users/user/git/node/emailer_test/node_modules/Handlebars/dist/cjs/handlebars/runtime.js:178:12) at ret (/Users/user/git/node/emailer_test/node_modules/Handlebars/dist/cjs/handlebars/compiler/compiler.js:526:21) at handler (/Users/user/git/node/emailer_test/server/routes/emailer.js:21:26) at <anonymous> description: undefined, fileName: undefined, lineNumber: undefined, message: 'Missing helper: "__mf"', name: 'Error', number: undefined } Debug: internal, implementation, error Error: handler method did not return a value, a promise, or throw an error at module.exports.internals.Manager.execute (/Users/user/git/node/emailer_test/node_modules/hapi/lib/toolkit.js:48:29) at <anonymous>

[kaywolter]

Thanks for providing a sample.. After a few modifications I got the error message you mentioned in your first comment:

this.__ is not a function

To me it seems like the problem is that you are losing the hapi context when using the Handlebars.compile method (correct me if I'm wrong). I'm afraid I can't really help you here as this is not an i18n related issue and I'm not really an expert on Handlebars :(

[epochslee]

I understand. Thanks for giving it a shot though Kay. I'll give it another go at it and will let you know if I find any solution. Will close for now.

[kaywolter]

No worries.. Would be interested in the solution though :)

[oprogfrogo]

Hi Kay,

Just wanted to get back to you about the solution I found for the handlebars compile I came up with. Thought it might be helpful to you and your users:

https://github.com/oprogfrogo/handlebars-hapi-compile-i18n-example

Just npm install, run it and navigate to http://localhost:4321/mailer. You will see the output in the console.

This is my personal git account. Cheers!

[kaywolter]

Great, thanks for sharing it :)

[epochslee]

👍

[DanielAlcaraz]

Hi Kay,

Just wanted to get back to you about the solution I found for the handlebars compile I came up with. Thought it might be helpful to you and your users:

https://github.com/oprogfrogo/handlebars-hapi-compile-i18n-example

Just npm install, run it and navigate to http://localhost:4321/mailer. You will see the output in the console.

This is my personal git account. Cheers!

I'm having the same issue. I see that you translate the messages in a variable and then pass it to the file as an option. I have some emails with a lot of text and I prefer to don't translate it before compile the template.

The helper seems that for routes work ok, but when you try to compile with Handlebars doesn't work.

Any help?

[DanielAlcaraz]

My temporally solution was send the __ function in the data. So when the helper access to this object it has the variable.

Mailer.send('password-reset', user, request.i18n.('EMAIL.SUBJECT'), { resetURL, : request.i18n.__ })

There is any way to access the i18n without the request object?