Previsualizaciones en línea de PDFs

:discourse2: Resumen Vistas previas de PDF en línea es un componente de tema solo para escritorio que le permitirá crear vistas previas para archivos adjuntos en PDF.
:eyeglasses: Vista previa Vista previa en el Creador de Temas de Discourse (solo escritorio)
:hammer_and_wrench: Enlace al repositorio https://github.com/discourse/discourse-pdf-previews
:open_book: ¿Nuevo en los temas de Discourse? Guía para principiantes para usar temas de Discourse

Instalar este componente de tema

Funcionalidades

antes

después

Como se mencionó anteriormente, este componente solo funcionará en escritorio. Hay muy poco beneficio en mostrar las vistas previas en dispositivos móviles, ya que todo será tan pequeño y muy difícil de leer.

Este componente utiliza la implementación nativa del navegador para renderizar los PDF, por lo que los resultados se verán diferentes en distintos navegadores.

Además, tenga en cuenta que las cargas de PDF no están permitidas de forma predeterminada en Discourse. Si desea permitir que sus usuarios carguen archivos PDF, deberá agregar esa extensión a authorized_extensions si desea que todos sus usuarios puedan cargar PDF, o a authorized_extensions_for_staff si desea limitar eso a los miembros del personal.

:information_source: Si utiliza S3, es posible que también necesite actualizar su política CORS. Consulte la publicación a continuación: Inline PDF Previews - #106 by JammyDodger

¿Cómo lo uso?

  1. Instale el componente
  2. Permita las cargas de PDF
  3. Actualice la página
  4. Cargue un PDF

Eso es todo. El resto debería funcionar automáticamente.

Configuración

Nombre Descripción
modo de vista previa En línea: Los archivos adjuntos en PDF se renderizarán en línea dentro de las publicaciones

Nueva pestaña: Los enlaces de archivos adjuntos en PDF llevarán al usuario a una nueva pestaña donde se renderizará el PDF

Funcionalidades adicionales

Si desea que un PDF individual no se renderice en línea, simplemente puede agregar un espacio antes del nombre del archivo, por ejemplo:

Esto se mostrará en línea

[sample-pdf.pdf|attachment](upload://usvbcKiQSWqA3w10gnf5PtydiXR.pdf) (82.9 KB)

Esto no se mostrará en línea

[ sample-pdf.pdf|attachment](upload://usvbcKiQSWqA3w10gnf5PtydiXR.pdf) (82.9 KB)

:discourse2: ¿Alojado por nosotros? Los componentes de tema están disponibles para usar en nuestros planes Estándar, Empresarial y Corporativo.

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I’m hosting my uploads and images on S3, and the preview is blocked by a “CORS policy: No ‘Access-Control-Allow-Origin’ header is present”.

Below is what Chrome console says:

Access to fetch at 'https://travelmassive-discourse-cdn.s3.dualstack.us-west-1.amazonaws.com/original/2X/b/b578f6364592121964e6a2fd4969e5c1222bd909.pdf' (redirected from 'https://lounge.travelmassive.com/uploads/short-url/pTnA3r043WfhDK8HSdPQrtNn8Lf.pdf') from origin 'https://lounge.travelmassive.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

Update

I was able to fix this by adding the following CORS policy in my S3 bucket configuration.

<CORSConfiguration>
 <CORSRule>
   <AllowedOrigin>https://mydiscourse.url/</AllowedOrigin>
   <AllowedMethod>GET</AllowedMethod>
   <AllowedHeader>*</AllowedHeader>
   <ExposeHeader>Access-Control-Allow-Origin</ExposeHeader>
 </CORSRule>
</CORSConfiguration>
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It’s necessary to add, that if you see this text in the error message from origin 'https://lounge.travelmassive.com' has been where your domain is without slash / at the end, then in the CORS configuration you should also add your domain without slash at the end like this:
https://mydiscourse.url

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I noticed that your uploads are on AWS so, the issue is probably CORS related (the component is not active on your site for me to confirm). See the post below yours.

thanks for sharing that!

Please note that this issue will only affect self-hosters that have set up something like S3. Self-hosters that are not using S3 will not run into this issue. Customers hosted by CDCK will also not need to worry about that since they already have that set up.

That said, CORS configuration is a bit outside of the scope of this topic. If your uploads bucket does not allow your own domain access, then that needs to be fixed regardless since there might be some other issues caused by that.

I’m a little bit unsure what happened here. Both cases seem to be working for me everytime I try. We can just chalk it up to a transitory network issue but please let me know if you see it again :+1:

I pushed a tiny update to this component that should improve the loading perception, there’s now a theme-color based placeholder instead of the default browser Iframe styles. It only shows up while the file is loading so 99% of the time, you won’t even notice it.

Given that most PDFs will load instantly I didn’t feel like adding a spinner would be worth it.

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Would it be possible to make PDF Preview suppressable by prepending a space before the upload link, like with oneboxing? Sometimes you want a list of documents and not previews. Sometimes you want a preview.

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I’m on Safari on MacOS Catalina, and I don’t have anything disabling in-browser PDF display—for instance, http://www.orimi.com/pdf-test.pdf displays fine. But I’m still getting the “Blocked Plug-in” window/message when I view the preview in theme-creator.

Site-specific settings in Safari prefs aren’t any different than other websites.

Is that happening for anyone else?

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Still not working for me on Safari in MacOS Big Sur. No special settings to blog plugins, and other PDFs display in the browser.

Safari Web Inspector has the following complaints when loading the preview page in theme-creator:
Unrecognized Content-Security-Policy directive 'worker-src'.
Refused to load blob:https://theme-creator.discourse.org/7b9b62c7-e782-4080-a521-04e3b06aa142 because it does not appear in the object-src directive of the Content Security Policy.

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This would be a vast improvement to this component! Is that doable, @Johani?

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Same issue for me on Firefox, but only after the 2nd visit :wink:
Is there a workaround for this? Manual declaration in the CSP config?

Thank you

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This has stopped working on my site. I get a big black box instead of the PDF preview:

Disabling plugins via Safe Mode makes no difference, nor does removing every other Theme component.

It has happened after moving image and file uploads to S3, which might be the culprit. I hope not, because they can’t be moved back easily!

I’m stumped. Shame, as it is a great component. Any suggestions?

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I am seeing the same behaviour with s3 uploads on.

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Are you still able to download the pdf ?
Still working for me (s3 + secure media and no cdn) :thinking:

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Yes, we are. Have the same setup as you (I think).

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:thinking:

  • my links in the messages are in the form of domain/secure-media-uploads/original/...
  • but in the console/network I can see that the actual downloads come from the bucket
    Do you see the amz credential ?

if not maybe this coud help ?

I also remember that something weird was happening when I tried to move a post from categories (or was it a copy/paste?) it finally worked when I re-uploaded the file.

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I am experiencing this same behavior on a fresh discourse installation and a fresh PDF attachment.

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Thanks @Benjamin_D. Turns out I don’t have secure uploads enabled, and my links all look nice and work fine, such as this one:

https://healthforum.nz/uploads/short-url/jyY18nDviITy5inQ3Rw7xQp0cyS.pdf

So I’m stumped - especially as to why it works in two forums I run and not the other - S3 being the only difference. And that you have it working with S3. I’m really confused.

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After updating to the latest version of discourse, the pdf-attachements are no longer displayed. What could be the problem ?

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It may be a conflict with another component or theme. It’s working as expected for me. Start by disabling other components and try using the default theme if yours is different. Same with plugins.

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Ok - I’ve made progress. Disabling S3 uploads fixes it for new uploads. But I’m left with a S3 / local mess if I go down that road!

If could be that I am not using the CDN thingo (CloudFront) which throws up the annoying errors on the admin page. I’ll have a crack setting that up and see if that works.

later - nope, a CDN makes no difference.

much later - have removed S3 uploads successfully (with a bit of sweat) so all good now.

Now, I’m keen to improve it! Is any clever person with the skills interested in giving this a crack?

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Estoy buscando un plugin que permita abrir el PDF en una nueva pestaña.
El comportamiento actual de mi Discourse es permitir solo la descarga.
¿Sería posible lograrlo con un tema similar?

5 Me gusta