Gofpdf: Generate PDFs from Go with No Dependencies | Hacker News Reader

Gofpdf: Generate PDFs from Go with No Dependencies

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168 pointsingve34 comments

We use this to generate the NYTimes Crossword PDFs. I'd say the API is a little wonky (there are several different methods just for writing text) but it gets the job done. I wish it supported font compression though. We have to pipe the PDFs through ghostscript to get them back to a reasonable size.

Can your employer sponsor a developer to implement compression?

or just do it in your free time to give back! some of my favorite personal projects (like my decimal library) were things i might've been able to justify doing at work, but decided to explore on my own time.

Nah, open source needs funding.

I don't think Newspapers have a lot of money to give away these days.

Rarely do companies do things from the goodness of their hearts, simply because it would be nice for other people. I don't see why anyone would do it for them. If they want a feature they should get it done themselves.

Supermarket lady doesn't take pull requests.

If you don't mind, what do you use to generate crossword puzzles? Maybe it's an open source software?

It's also worth noting that Chrome headless could be a nice alternative if you use html as the base for say invoices or reports that you want to generate from a SaaS app.

Create pdf with Chrome headless: chrome --headless --disable-gpu --print-to-pdf https://www.chromestatus.com/

Source: https://developers.google.com/web/updates/2017/04/headless-c...

If you are looking for a hosted API on top of Chrome headless, I built https://pdf.cool

Disable GPU because they assume headless servers don't have graphics cards installed ?

You would also probably need to have DISPLAY pointing to an X server (to get OpenGL), which is somewhat cumbersome for daemons to do.

Luckily I haven't had the need to create pdfs yet now that I'm using Go. However, if I would, I would generate LaTeX instead of PDFs directly. I did the same in Python a and it has turned out great: https://github.com/JelteF/PyLaTeX

The API can be made much more high level, because of all functionality and packages LaTeX has. The most important thing is to have a good escape function that is used by default for all text, otherwise it's very easy to execute arbitrary shell commands for an attacker. If anyone wants to create a Go package similar to mine, feel free to contact me if you want any more advice (email in github profile).

That "no dependencies" thing is important sometimes. Latex is a large dependency.

I agree that sometimes not having dependencies is important and that's definitely a big feature of this library. However, in my experience it is more desirable in many cases to have clear code. You basically get this for free when by using LaTeX, because you create documents at a higher level than writing raw pdfs. Another big advantage ia that you can make use of its vast package ecosystem, which allows you to for instance create beautiful tables that span multiple pages with ease.

It definitely is a large, and more importantly external, dependency though. However, if you control the installation environment of your software this isn't really a problem. For all use cases where I had to generate pdfs this was the case (webapps and local one off scripts).

I agree. No dependencies is nice, but you step into a myre of dealing with low level pdf faffery. I'd rather let a very robust external tool with proven reliability

That is a large understatement. TexLive is like 4GB

This. We used a similar approach in my lab (but in MATLAB) to build reports of a certain experiment. The experiment generated a large amount of data daily; MATLAB was used to ingest and process the data, producing the necessary vector figures and tables and then called a pdfLaTeX template that produced the final, beautiful PDF report. Finally, the script sent the report by mail to our inboxes.

I recently used this to create a language agnostic tool that generates reports in an unified format for two different services.

Can't say it's completely painless due to the imperative nature of the API but it served me well. If you're reading this, thank you maintainers!

Do you what one would use to generate professional looking report PDFs?

The quality of the report depends significantly on the designer. I've seen some very good looking documents generated client side with pdfmake (JavaScript). In my SaaS product (link in profile), we generate PDF invoices with it, and they look very professional. It's a bit painful to get things typeset correctly, but once you have it right, the documents look great. pdfmake is a good option if you don't want to load your server CPUs up with generating PDFs...

I've built a SaaS service that generates PDFs, and I've just added an HTML/CSS editor for this purpose [1]. It uses Liquid templates and SASS. After you set up all of the fields, you can just post data to a simple API. We also provide an online form that people can fill out.

If you just need to post your own HTML/CSS and get a PDF, then I'd recommend DocRaptor [2].

[1] https://formapi.io/templates/tpl_mFAsZEmhCtG9FX5N/edit

[2] https://docraptor.com

This worked quite fine and the output is more than satisfactory. We were looking to replace both a slow interpreted PDF renderer and a Webkit-based solution, the first one not up to our standards and the second one too much of a security gamble for the nature of the project.

I wouldn't recommend it however if your design is complex, you're on a very tight schedule and you can stomach Webkit. Truth is Gofpdf requires careful coding and testing to make sure you're drawing things in the right places. You draw using simple primitives positioned around the page with a "cursor"; not something that lends itself to pumping out flashy results in little time.

Your second paragraph is exactly why I built FormAPI [1]. We have a UI to position form fields, so you don't have to do everything in a text editor. (We also have an HTML/CSS editor to create your own templates.)

[1] https://formapi.io/templates/mr4ekGhgZTptdQaN/edit

We're mostly web developers so we designed our complex shipping invoices in HTML and ran them through DocRaptor's API https://docraptor.com for many years with beautiful results at a reasonable cost. Eventually other teams in our organization started doing the same so we paid a few thousand bucks for the package DocRaptor uses in the backend https://www.princexml.com and run it locally.

Latex is very easy to generate from any programming language, because it's just text. I created a Python package for it with an easy and extensible API: https://github.com/JelteF/PyLaTeX

If you want to create something similar, be sure to escape untrusted input though. With an escape function similar to the one in my library. Otherwise it's very easy for an attacker to execute arbitrary commands.

It's not a Go program but Microsoft Office or Apple's equivalent can make "professional looking" reports you can export to PDF. You could also use Photoshop if you want to be more creative or LaTeX if you're going for a minimalistic look.

I meant programmatically customizable "reports" like invoices with charts. Sorry I didn't mention.

Shell out to wkhtmltopdf.

Just to say, we did this and it looks pretty good, most importantly though the templates including any JS if necessary makes this _very_ easy for designers to work with on their own. Downside is that the browser is pretty old.

I used this library to build the PDF client[1] for the deck [2] Go package. Here are some examples [3, 4, 5]

[1] https://github.com/ajstarks/deck/

[2] https://github.com/ajstarks/deck/tree/master/cmd/pdfdeck

[3] https://speakerdeck.com/ajstarks/the-other-side-of-go-progra...

[4] https://speakerdeck.com/ajstarks/a-view-of-design-and-user-e...

Thank you so much for Deck! I used it for a few talks recently, you can find two of them about Go on my BitBucket page: https://bitbucket.org/teknico/ You also have a pull request on Github. :-)

A mostly straight port from PHP to Go is pretty interesting. Nice to see PHP libraries get a little love here and there.

I've used fpdf years ago to make invoices on websites. I really like this library and it's cool to have it in Go.

It's not just a HTML to PDF library, it lets you make very precise stuff, and it was very useful back in the day.

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