Excel to pdf conversion in rails4 with libreoffice - ruby-on-rails

In a rails 4 application, how can I convert an excel spreadsheet file into pdf.
When I am trying to implement Excel to pdf the contents are listed in different pages if excel column size is large.
How to generate the pdf without moving data to next pages in pdf.
Please help,
Thanks

So you basically have two options you can either implement this yourself and use a CSV gem/library (default CSV, faster CSV, or smarter CSV) assuming that by "excel" a CSV is acceptable. If a CSV is not acceptible you can use the axlsx gem instead. Then for pdf conversion you can use something like prawn. If you decide to build this yourself follow these steps.
Create a controller that will handle Reports, I suggest using the rails g controller report upload generate_table show generate_pdf generator to create a controller and a view for the upload process
Create a file upload form in the upload view.
On submit you will send the file to the generate action processing with one of the CSV or excel gems
Once processed your end product should be an array or hash (as an instance variable) and you can send that to the show action
In the show view you will iterate of that hash/array and incapsulate the contents in a html table.
On the show view you should have a button that will send that same hash/array to the generate_pdf controller action where you will use prawn to create a pdf, you can use something like send_data to the send the completed pdf file back to the user.
This is roughly how you could go about it less the low level details. Now if you wanted to use an out of the box solution you could use something like Ruport. Ruport will handle most of the heavy lifting for you the only thing is you need to have your models and associations set up to use it the way it is designed, and that may not be an option for you.

Related

Create object in Rails from text file

I am building a site with Ruby on Rails where I can display items that are for sale. Currently I can add new items by filling a form with title, price, some text and upload a couple of pictures.
Since there might be many items I would like to have a text file with the data, one item on each line, data separated with comma or whatever. Then I'd like to give this file to my Rail's application that will create the items in the application. Would this be possible?
What you're basically talking about is importing and exporting CSV files.
You can learn about the basic ruby functions available to you when working with CSV files here: http://ruby-doc.org/stdlib-2.3.0/libdoc/csv/rdoc/CSV.html
Here's a video about exporting to csv and here's a video about importing from csv.
You essentially will call :to_csv on some collection, and then use CSV's foreach or some method of iterating the items in the CSV, and you will create your rows from the parsed data.

PrawnPDF Flip Entire PDF

I'm using Prawn PDF to create a label that I send to a label printer, but the label prints upside down. This is important as the shipping labels we use come with some print already on it. The setup I'm using (an iPad through a Lantronix xPrintServer to a Zebra Printer) won't allow me to flip it using the drivers.
So I'm wanting to know if there is a way using Prawn (or even just Rails) to flip the entire document (which contains 2+ pages) so it prints out correctly on the labels. The order of the pages isn't essential.
I haven't used Prawn lately, but I'm pretty sure using the rotate method at the top of your code will work. You'll just need to either set the origin to the center of the page, or use translate to reposition the content after rotation. Page 29 in the manual (PDF) has some example code.
You could save the pdf to a file and then use the awesome pdftk to rotate the saved pdf, then send the amended version.
https://www.pdflabs.com/docs/pdftk-cli-examples/
EDIT - pdftk is not a library/plugin/gem, or any kind of Ruby for that matter. It's a command line tool which you would use like this, in your controller, replacing your current "generate and send pdf" code.
#instead of sending the pdf straight to the user, save it to a file
#i'm not sure how to do this in prawn but it can't be difficult
#rotate the original to a new file
`pdftk /path/to/original.pdf cat 1-endsouth output /path/to/rotated.pdf`
#you could test whether the rotated file exists here as an error-check
#then use send_file to send the rotated one as the response.
send_file "/path/to/rotated.pdf", :type => "application/pdf"

mvc file upload and database insert

I'm just getting my head wrapped around MVC in .net using VS 2013.
I need a little direction in regards to uploading a file (which is easy) but also inserting data about that image into a database. Specifically I want to allow the end user to enter a description, title etc. about the file being uploaded. On the back-end I want to also add to the meta data a 'Date Created', 'Path to the file', 'Category', and the File Name and a couple other pieces of data that will help with presenting files in the views. I don't want to insert the files in the DB but just use the path in the generated HTML to point to the physical file so the end user can view or download it.
Multiple file types are being used, Audio, Video, Documents, Images.
I can get the file upload to work but writing the controller to accept a file, and end user input, then also add the other fields I need into the database that the user never sees is where I'm stuck. Blending the file upload with the user fields and beack end data is confusing me on how to get all the pieces to work together.
So in short getting File Upload + User Input + non-User Input values all in the same View, Controller, and Model is what I need direction on.
You have to upload your image plus data in a multi-part form.
In your view you will create a POST form that uses "multipart/form-data" encoding, you can then include inputs for model data and your file upload control within the body of the form. When it submits will will create a multi-part form, one part will contain the binary file and another part will contain your data.
On the controller action side you will receive the data with an action akin to
public ActionResult PostFile(MyModel model, HttpPostedFileBase file) {...}
There are numerous posts on SO with more details so I won't go into that.

How to send file from action to next action

I'm new in RoR.
I want to make that logic:
User upload xml or csv file from /home (static_pages#home) and send it to elms#el_select
If file is xml and file contain more than one element I want to show page to user so him choose which element he want to show
If file is csv or xml with one element I want to show result page
So here is two use-cases:
- choose file - view results
- choose file - choose element - view results
In second case I upload file in static_pages#home, send it to elms#el_select and I don't know how to send it from elms#el_select to result page.
In first case I don't know how to skip page rendering and send file to another controller
Controllers do not store files for up/download or any other data. They just manipulating with instances of their models (with their behaviour). So, if I have understand your question in the right way, the order may be next:
StatiPagesController take the file from user and store it somewhere (/tmp or smth.) if the file is valid;
ElmsController take the file from storage and render the proper view (or redirect_to proper view if such already exist).
Finally, I've found answer on my question:
#key = SecureRandom.uuid
Rails.cache.write(#key, #file)

Mail merge in ruby on rails, but in big numbers

I am trying to implement sort of mail merge for printed documents in Ruby on Rails 3.2. I have about 8000 recipients and template origin in Microsoft Word. Template includes images (photos) and contains about 10-20 pages.
Actual situation is, that I rewritten original template to Textile (redcloth) and pictures are inserted from internet (http address). I did all personalisation etc. So I generate HTML file and must divide it to many small files each for 1000 pages. Total I need print about 8000 x 20 pages = 160.000 pages.
Anyone know how to print it to PDF from HTML? Or how to insert commands for changing paper tray (for first and last page) or for binding after each 20 pages etc?
Thank you for any idea :-)
Here's one idea: in your rails app, set it up to return one html per user. Also, have a nice /users/ index method that returns a list of users in something convenient, maybe json format.
Now, you want a local script, written in ruby, bash, whatever is convenient, to:
fetch a list of users from that /users/ method, probably save it to a file
loop over the list of users (from the file, so they're not all in memory), and fetch the HTML of the email
generate pdf from each HTML downloaded, either inside the loop, or loop over files in a directory where you saved the HTML. Use wkhtmltopdf or similar.
send each pdf to the printer, again either inside the same loop, or loop over the saved pdf's.
If you wanted to get fancy, and a little more efficient, you could use a queueing system like resque, and make each of those bullet points into a queue, and run one worker per queue. That would let you start printing some pdfs while others were still being downloaded and converted, so it should be less time overall. But if you're not already familiar with a queuing system like that, a simple script should get it done as well.

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