Specifying multiple templates in metas can never succeed #271

Originally reported by someone else on Discourse: it seems that when multiple templates are specified in the metas of a Pollen source, those templates will never be used.

Within an empty folder with these files:

#lang racket

;; pollen.rkt

(module setup racket/base
  (provide (all-defined-out))
  (define poly-targets '(md sexp html)))

#lang pollen

◊;; index.poly.pm

◊(define-meta template '("topic-welcome.html" "topic-welcome.md"))

◊title{Hello, new topic}

Do the following (I did this in the terminal because DrRacket was giving me weird errors, even in this simple scenario, both on Mac and Windows):

❯ racket
Welcome to Racket v8.9 [cs].
> (require pollen/setup pollen/render pollen/cache)
> (cached-metas "index.poly.pm")
'#hasheq((here-path . "/Users/joel/code/sandbox/pollen-issue-2/index.poly.pm")
         (template . '("topic-welcome.html" "topic-welcome.md")))
> (parameterize ([current-poly-target 'html])
    (displayln (get-template-for (simple-form-path "index.poly.pm"))))
/Users/joel/code/sandbox/pollen-issue-2/template.html

I think the original reporter is correct that the problem is in c182a30f57/pollen/render.rkt (L454-L463):

(define template-name (if (list? template-name-or-names)
                                (findf (λ (tn) (eq? (get-ext tn) output-path-ext)) template-name-or-names)
                                template-name-or-names))

The first argument to eq? here will always be a string, and output-path-ext might sometimes be a string and sometimes a symbol (if the result of (current-poly-target) is used); either way this comparison will always fail.

Originally reported by someone else [on Discourse](https://racket.discourse.group/t/pollens-define-meta-isnt-working-get-template-for-ignores-it/2028): it seems that when multiple templates are specified in the metas of a Pollen source, those templates will never be used. Within an empty folder with these files: ```racket #lang racket ;; pollen.rkt (module setup racket/base (provide (all-defined-out)) (define poly-targets '(md sexp html))) ``` ``` #lang pollen ◊;; index.poly.pm ◊(define-meta template '("topic-welcome.html" "topic-welcome.md")) ◊title{Hello, new topic} ``` Do the following (I did this in the terminal because DrRacket was giving me weird errors, even in this simple scenario, both on Mac and Windows): ``` ❯ racket Welcome to Racket v8.9 [cs]. > (require pollen/setup pollen/render pollen/cache) > (cached-metas "index.poly.pm") '#hasheq((here-path . "/Users/joel/code/sandbox/pollen-issue-2/index.poly.pm") (template . '("topic-welcome.html" "topic-welcome.md"))) > (parameterize ([current-poly-target 'html]) (displayln (get-template-for (simple-form-path "index.poly.pm")))) /Users/joel/code/sandbox/pollen-issue-2/template.html ``` I think the original reporter is correct that the problem is in https://git.matthewbutterick.com/mbutterick/pollen/src/commit/c182a30f57ea5096440aea3d097f5fe3b78bb236/pollen/render.rkt#L454-L463: ```racket (define template-name (if (list? template-name-or-names) (findf (λ (tn) (eq? (get-ext tn) output-path-ext)) template-name-or-names) template-name-or-names)) ``` The first argument to `eq?` here will always be a string, and `output-path-ext` might sometimes be a string and sometimes a symbol (if the result of `(current-poly-target)` is used); either way this comparison will always fail.

Sounds right to me. Thanks.

Labels Milestones

Specifying multiple templates in metas can never succeed #271