Tensorflow does not officially support Ruby. I was wondering how one can use tensorflow, full version (Python or JS), in a rails app.
While this is a general question, the answer may be of use to the community. No one has asked this and many people new to using other languages like Python in Rails would benefit.
Another way to state this question is what some of the successful companies using rails are doing to use tensorflow.
I'm only going by its readme, but the tensorflow ruby gem appears to be well supported.
This post shows how to use it to classify images
(I take directly from the article here)
Steps:
Clone and install tensorflow.rb
Go to image directory
Download this zip file from google
extract the file ‘tensorflow_inception_graph.pb’ in this directory.
Do ruby classify_image.rb (This will work on the default image of the Mysore palace).
To try this out on your own images you can add the image to this directory and then change file name in line 31 on classify_image.rb .
Related
I'm trying to create a PDF preview for my PDF files, but I don't know where to start, I'm using poppler gem on Ruby on Rails.
The app is giving me this message: "ActiveStorage::UnpreviewableError in Tasks#show"
So I'm not understanding where should I need to declare the preview
Looking on google I found several sites with methods, but I don't know where to add this code, I've tried by creating a new folder on the app directory, but this didn't work.
In activestorage documentation says about requirements to use this feature.
libvips v8.6+ or ImageMagick for image analysis and transformations
ffmpeg v3.4+ for video previews and ffprobe for video/audio analysis
poppler or muPDF for PDF previews
Check if in your environment has the requirements
Thanks for the advice, I realized I haven't installed muPDF on my environment, the thing that worked for me was to install it from the home directory (outside my project) and that's it, now the preview is working perfectly fine.
https://ubuntuhandbook.org/index.php/2018/05/install-mupdf-1-3-0-ubuntu-18-04/
I've been working on a Ruby parser, that fetches data from different API sources, and compile this data into a clear read-to-use JSON file.
For my use case, i need to store the data i'm initially fetching from the different sources as i don't want to fetch them each time I use the code.
For now i'm writing the JSON i'm receiving from the API sources locally into different JSON files stored in a data folder where my ruby script is. Then i read those files again, parse them and generate my new formatted JSON file that i'm gonna use later in a Rails app.
For that matter i want to create a Gem from this ruby script, which i'm currently working on. Nevertheless i'm not sure to fully understand how and where i should store that data (the one i'm fetching and the one i'm generating).
For now i have tried to simply keep the code as is and simply try to write the file like so:
URI.open("path/to/where/i/wanna/store/file.json", "wb") do |file|
file << URI.open(fetched_data_url).read
end
But wherever i try to write the data i get a :
No such file or directory # rb_sysopen path/to/where/i/wanna/store/file.json
Which in a way does not surprise me that much as i expected it to work in different ways in the context of a Gem. But i'm still missing something here about how to handle this. I'm not sure to fully understand how that all works, especially when you use paths in a gem that will ultimately be used in a rails project.
So several questions here:
Whenever you use a path to write a file inside a Gem, is that path relative to the gem or to the project that will ultimately use that Gem? (and consequently will the file be written inside the project that uses the Gem?)
In that precise use case here, what should i do about it? Where and how do i store my data so that i can use it later? knowing that i need to store it as a JSON file and that for now any attempt of writing a file ends up with an error.
Any input on what i'm misunderstanding here would be much appreciated ! Thanks !
Whenever you use a path to write a file inside a Gem, is that path relative to the gem or to the project that will ultimately use that Gem?
There is nothing special about using file paths whether the code is part of a Gem or not.
path/to/where/i/wanna/store/file.json is a relative path, which means it is looked up relative to the current working directory of the user who started the script. That's nothing special about Gems, that's not even anything to do with Ruby. That is just how file paths work. Relative paths are relative to the current working directory, absolute paths are not.
Where and how do i store my data so that i can use it later?
This depends largely on the Operating System Environment. Different OS Environments have different conventions where to store what kind of files. E.g. your files look like they fit the definition of a cache and Windows has a dedicated folder for caches, as does macOS, as do Linux distributions that follow the Linux Standard Base, as do Desktop Environments that follow the Free Desktop Standards, as does Android, as does iOS, …
For example, the Free Desktop Group has the XDG Base Directory Specification, which defines directories for application state, application data, application cache, and many other things for XDG-compliant environments. Microsoft has similar specifications for Windows. The LSB has something to say as well.
I'm aware of pdf-stamper, but I'm trying to avoid switching everything to jruby right now.
I just need to "stamp" an image that I generate within the rails app (a PDF417 barcode) into a form field in the PDF document (there's an FDF; it's a document template kinda thing).
I'm filling out the text-based fields by just shelling out to pdftk, so if there's a way to do it using pdftk, I'd be fine with that, but I've looked high and low for one without any luck.
How about using a barcode font? some alternatives too. I haven't used that one but there may be others available too
I know I'm late to the party, but the PDF417 Rubygem should do what you need. https://rubygems.org/gems/pdf417 will generate it and if you have chunky_png installed you can easily write out PNGs to a file.
I have a requirement of uploading a file to my disk through my webpage. Seems like I have two options
My requirement is specific that I will upload ONLY text files.
Using default rails methods to upload a file.
Ex: http://www.tutorialspoint.com/ruby-on-rails/rails-file-uploading.htm
Using a plugin like 'PaperClip'
Following are my concerns:
I want to keep the file upload as simple as possible
Keep as away as dependencies like Imagemagic etc
I'm using rails 2.8.3
concurrent file uploads can be happen by multiple users
please can someone tell me what are the pros and cons of having
writing a simple file upload (option 1)
using a plugin/gem to upload a files
Writing your own file uploader is an option, but using a pre-built gem provides you with all of the code you need, straight after install.
Gems will usually have all of the functionality packaged into them that handles all of the cross-platform issues and security headaches your likely to run into by writing something from scratch. A well maintained gem will also have a good community behind it, keeping things up to date.
The popular Gems out there are really easy to use, and unless you are resizing images etc, you shouldn't need ImageMagick installed. Have a look at these:
http://railscasts.com/episodes/134-paperclip
https://github.com/technoweenie/attachment_fu/wiki
Paperclip is far easier to build a simple upload form with, but I'm not sure if it works on Rails 2. Attachment_fu is an old favorite from the Rails 2 days and will definitely be able to handle your problem, it just requires a little more configuration.
is there a way to generate pdf documents from latex in rails 3? We've been using rtex (http://rtex.rubyforge.org/) in a rails 2 application, however it doesen't seem to work with rails 3.
Our rails application generates invoices using a latex template which we also use to create invoices by hand. Hence we would have to maintain two templates if we had to find a different solution for the pdf generation in rails 3.
Best I found to do such things was to create the .tex files on the server, then call a rake task that ran a "pdflatex" system command.
It is pretty poor in performances I guess, but it's designed for a single admin and works fine for me, on my local machine, and I can use the same latex templates for my letters
Old question, but I'm sure this'll help anyone coming to this page now.
Take a look at the rails-latex (LatexToPdf) gem.
The LatexToPdf.generate_pdf method takes in two arguments:
tex content
a configuration hash
...and returns the pdf binary, which you'll have to write to a file.
I suggest reading through the source to if you need to add configuration.
Note that under the hood, the rails-latex gem still depends on a TeX extension (which you'll need to download) to generate the pdf. The default is pdflatex, and I've personally used xelatex.
As of the writing of this answer, this gem is described as a renderer for rails 3; though it now includes support for rails 4 and 5.