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Show HN: PDF API – Generate, convert, and modify PDF documents

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Re: Show HN: PDF API – Generate, convert, and modify PDF documents

#71

Post by newlisp »

amluto wrote: post #65

I find this utterly bizarre. Once upon a time, if you wanted to left pad a string, you would just do it. A while later, people discovered that you could use a library. (I’m joking a bit here, but libraries are genuinely useful.). With a library, you get to pick from various schemes and schedules for updating the library, but you have a degree of control. But now apparently you’re supposed to use a web API and depend…

Nodejs forces this architecture(no, worker threads are not a solution, they are heavy and have too many restrictions), you don't want to slow down the event loop with heavy PDF processing.

Re: Show HN: PDF API – Generate, convert, and modify PDF documents

#73

Post by matchagaucho »

gyulai wrote: post #19

Not a good usecase for an online API. To the extent that those PDFs could include sensitive information, there's a huge security/privacy headache there, with no real benefit when compared to performing these functions offline. It also seems to me a lot more expensive than alternative ways of doing the same thing.

FUD. Most companies are using Box, Dropbox, or some variant of cloud-based document storage today. Extending storage services with document transformations and conversions is a logical evolution.

Re: Show HN: PDF API – Generate, convert, and modify PDF documents

#74

Post by matchagaucho »

gyulai wrote: post #27
arkgil wrote: post #22

Earlier quoted context omitted.

That's a great point. For folks that have strong privacy needs, we do have an on-premise product that provides the same functionality [1]. [1] https://pspdfkit.com/server/processor/

So what exactly does that leave? A wrapper that you've created around weasyprint, pandoc, latex, ghostscript, imagemagick, and stuff like that? Sounds to me like an unnecessary extra expense for an unnecessary extra layer of abstraction. And there's a risk factor that comes with it: Say I make a nontrivial investment, like write a book that I'm planning on typesetting with this, or write a reporting infrastructure th…

Then I come back to it 10 years later, because I'm writing the second edition of the book, or I want to change something about my reporting infrastructure.

Those seem like one-off PDF conversion use cases that MS Word or Acrobat can easily handle. Not a high-volume, daily PDF invoice use case.

Re: Show HN: PDF API – Generate, convert, and modify PDF documents

#75

Post by danielrhodes »

amluto wrote: post #65

I find this utterly bizarre. Once upon a time, if you wanted to left pad a string, you would just do it. A while later, people discovered that you could use a library. (I’m joking a bit here, but libraries are genuinely useful.). With a library, you get to pick from various schemes and schedules for updating the library, but you have a degree of control. But now apparently you’re supposed to use a web API and depend…

This really does not resonate at all, and I have the scars to prove it.

I used to work on a browser-based document management system, and I would have used (or at least tried) all of these APIs without hesitation. PDFs are a pain and the mish mash of poor functioning tools that exist provides a constant headache.

1) OCR'ing of a PDF is difficult. The only good service is Google, but requires that you break it into pages as images to be performant. This would have simplified things greatly. Even if the PDF has text inside and is not an image, it can be wrong or not laid out in a linear way, so you have to OCR it. Command line tools do not get you very far. An example: if you OCR or text extract a PDF with multiple columns of text, does it handle the columns well?

2) People want searchable OCR'd PDFs where you can highlight the text, even when it's a bitmap underneath. This requires a technique where you overlay transparent text in the exact position of text in the bitmap. This does not come for free and I've only seen this done on proprietary Windows-only software. This alone would be worth it.

3) Office to PDF is an extremely standard need, especially if you want to display them online. But it's not easy. You have to hack together a headless OpenOffice to have it work at all, but it doesn't do a great job. It's difficult to do well because Office docs are like HTML pages in that it greatly depends on the renderer, not to mention the fonts. Microsoft does not offer a service to do this, unfortunately. If you think anything will do, it really won't: when people see their PDF looks very different than what they saw on Word, they get upset.

4) Table extraction APIs are super important, especially if you are trying to automatically extract data from PDFs (e.g. analyze financial disclosures). There have been whole startups dedicated to this.

5) HTML to PDF is also a pain: you have to set up an instance that is running headless Chromium, which can be quite slow. This has become the defacto standard to quickly create complex PDFs. Having a simple API wrapper around this is just one less thing to manage.

The rest of the APIs, like the merging/splitting/watermarking etc., are pretty standard and you do not need APIs if you already have access to the PDF on a server. But if you were in a browser or on mobile, you might not.

Re: Show HN: PDF API – Generate, convert, and modify PDF documents

#76

Post by amluto »

newlisp wrote: post #71
amluto wrote: post #65

I find this utterly bizarre. Once upon a time, if you wanted to left pad a string, you would just do it. A while later, people discovered that you could use a library. (I’m joking a bit here, but libraries are genuinely useful.). With a library, you get to pick from various schemes and schedules for updating the library, but you have a degree of control. But now apparently you’re supposed to use a web API and depend…

Nodejs forces this architecture(no, worker threads are not a solution, they are heavy and have too many restrictions), you don't want to slow down the event loop with heavy PDF processing.

This is not in any respect limited to NodeJS. If you want to do a 500ms computation, you don’t want to do it synchronously in your network thread. It doesn’t make much difference whether it’s C, Rust, NodeJS, Go, etc. (CGI is different: everything is off the network thread.)

But this doesn’t mean you should outsource computations to a third party remote system. You can have a local (same physical hardware or same data center) off-thread service (or just thread pool) to do this kind of work with much nicer properties.

Re: Show HN: PDF API – Generate, convert, and modify PDF documents

#77

Post by voiper1 »

I recently went down the PDF rabbit hole for a project.

I had to use different OSS tools to do everything I wanted. I was able to access three from within nodejs without touching the disk:

1) Libreoffice CLI for converting doc/docx to PDF. It handled the formatting remarkably well. WARNING: you must have the fonts on the system doing the generating or it will substitute "similar" fonts! NPM: libreoffice-convert

2) NPM pdfjs-dist from mozila for extracting text and finding page numbers.

3) NPM pdf-lib for manipulating PDFs: deleting pages, adding pages from other PDF files (even to the middle of a PDF.)

4) PDF Jam commandline for resizing a pdf `pdfjam --keepinfo --outfile "${path}.resized.pdf" --paper letterpaper "${path}"`;

Re: Show HN: PDF API – Generate, convert, and modify PDF documents

#78

Post by pipeline_peak »

danielrhodes wrote: post #75
amluto wrote: post #65

I find this utterly bizarre. Once upon a time, if you wanted to left pad a string, you would just do it. A while later, people discovered that you could use a library. (I’m joking a bit here, but libraries are genuinely useful.). With a library, you get to pick from various schemes and schedules for updating the library, but you have a degree of control. But now apparently you’re supposed to use a web API and depend…

This really does not resonate at all, and I have the scars to prove it. I used to work on a browser-based document management system, and I would have used (or at least tried) all of these APIs without hesitation. PDFs are a pain and the mish mash of poor functioning tools that exist provides a constant headache. 1) OCR'ing of a PDF is difficult. The only good service is Google, but requires that you break it into pa…

> Office to PDF is an extremely standard need

Is it really an extremely standard need or just something that appears in the bs corners of our jobs a few times a year.

Re: Show HN: PDF API – Generate, convert, and modify PDF documents

#79

Post by danielrhodes »

pipeline_peak wrote: post #78
danielrhodes wrote: post #75

Earlier quoted context omitted.

This really does not resonate at all, and I have the scars to prove it. I used to work on a browser-based document management system, and I would have used (or at least tried) all of these APIs without hesitation. PDFs are a pain and the mish mash of poor functioning tools that exist provides a constant headache. 1) OCR'ing of a PDF is difficult. The only good service is Google, but requires that you break it into pa…

> Office to PDF is an extremely standard need Is it really an extremely standard need or just something that appears in the bs corners of our jobs a few times a year.

Yes, if you're working with documents a lot it is. Word docs are not portable and people don't like them because they can be changed easily, not to mention not everybody has Word. You also can't display them in inline in a browser.

Re: Show HN: PDF API – Generate, convert, and modify PDF documents

#80

Post by danielrhodes »

voiper1 wrote: post #77

I recently went down the PDF rabbit hole for a project. I had to use different OSS tools to do everything I wanted. I was able to access three from within nodejs without touching the disk: 1) Libreoffice CLI for converting doc/docx to PDF. It handled the formatting remarkably well. WARNING: you must have the fonts on the system doing the generating or it will substitute "similar" fonts! NPM: libreoffice-convert 2) NP…

Libreoffice only does a mediocre job of rendering Word documents. There are a number of cases where it really mangles things. An example would be some types of bulleted lists or indentation.
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