I want to build QR Code of a particular string/url. After building, without saving I want to display the display the image. I don't want to persist the image. Something like http://example.com/qrcode?code=LOL,
should display the QR code for the string LOL.
Platform : Ruby on Rails 4
Thanks.
The best way is to do the process somewhere other than your server.
I'd suggest either using an out of the box API like: http://goqr.me/api/
Or even do it on the browser (if it's a web app) like: https://github.com/davidshimjs/qrcodejs
Disclaimer: I have not used any of these.
All the best :)
Related
I'm making a cribbage app for our slack channel. It's played using Slash commands. I'm currently showing the player their hand when they type the /showHand command, and it works, but I'd really like to be able to inline the image attachments but I cannot find a way to do this. Currently, it looks like this:
And if I use thumbnails it looks like this:
Is there a better approach? Possibly a way to add multiple images to one attachment? Possibly a display option to display response attachments inline?
UPDATE:
I followed Szymon Roziewski's advice and created a server-side module to download the card images I needed and create the final image of the player's hand. The images are cached so they only need to be downloaded once during the lifetime of the dyno.
I also contacted Slack support and I was told that inlining image attachments isn't currently possible but they might make it a future feature.
I am working on an iOS app where the users can add description/text when uploading images like Snapchat.
Do they render images and add the text to image so that it becomes part of the image itself or is it shown as a UILabel over the image?
For the 2nd option the text would have to be sent separately to server.
P.S. Just having an argument with Server side programmer and I'm suggesting the 2nd option.
If we check /ph/upload in Snapchat API (last updated 23-12-2013) we can see that you can upload either a photo or a video.
Of course, this is not the latest version (although this is the last documentation I could find) but I am assumming nothing has changed in that regard.
That means the text is inserted to the photo in the mobile client app, not on the server.
In my opinion, you shouldn't base any decisions about your API architecture on Snapchat because it's unlikely you have the same use cases. In general:
Sending data separately is more flexible and makes client implementation simpler.
Rendering data on the client is better for user experience (everything is faster and the user can see the final result) and also it saves a lot of server resources (the more users you have the more this will be visible).
I am trying to find the best way to render confidential images in a view, without storing the images within the rails application flat-filesystem, as I have no idea where to place the images. I am storing the image data binary as :text in a sqlite3 database table and successfully display the images using
<% s = "data:image/png;base64,#{ActiveSupport::Base64.encode64(#my_image)}"%>
<img style = 'width:100%; height:600px' src = '<%= s %>'/>
This works for me in Firefox and Chrome, but my client cannot get the images to display. I'll find out in an hour or two what browser they are using. Client says they want the image src url to look like a relative path within a controller's folder, which seems to contradict the notion of not storing the image in the flat-file system.
I think I am missing something very small here, but I would like to know the proper way to store images and documents in an application that are not public to all users. If my question is not clear or you need information, please let me know and I will provide more information.
I have read of attachment_fu and paperclip, but they appear to allow attachment downloads, and I just need to display an image inline on a page. Any help is greatly appreciated. Thank you much in advance.
You can keep files in non-public repositories and have controllers action with send_file(path, options = {}) It allows you store files somewhere on the hard disc and keep access logic inside your controller.
Have you tried the paperclip gem? You can upload images to amazon and amazon allows you to set permissions for files...if you want to do it that way.
As Artem says, Amazon is a great way to achieve this. But if I get you right, they want to see an URL to the image directly (i.e. be able to type the source into the address-field if they want to).
You need to decide wether everyone should be able to access the image (given they know the name/path), or to have authentication, in which case I don't think a relative path is worth anything.
Can't you just have an image-folder containing all images (not accessible by URL), and a table to lookup wether userX is allowed to see imageY?
Similar to Facebook's UI, I am attempting at generating a preview image from an external linked website. So that when a user types in a url he is linking, the UI will by default, scan that site for an img and scrape a preview thumb.
Is there a specific name for this technique? Or can anyone point me in the direction of learning this?
Thanks so much!
Its called scraping. There is a library called scrAPI.
Here is a code example http://crunchlife.com/articles/2007/08/13/code-snippet-ruby-image-scraper
There are a couple different options when it comes to page scraping. Another one to check out would be nokogiri, http://nokogiri.org/. You can find tutorials on how to use it at http://nokogiri.org/tutorials.
Instead of grabbing an image from the site, why not grab the image of the entire page? You could make use of a free screenshot service like http://www.websnapr.com/ or http://www.thumbshots.com/ among others. In one application, I use that for my preview image, and use nokogiri to scrape the page title and description. Just an idea.
I want to generate QR codes in ruby on rails, to run in the background of my website written in rails. Saw this http://code.google.com/p/qrcode-rails/ but cannot work out how I could get this to work for me. Basically in RoR I want to:
Pass a generator a string, my unique code, a 20 character length number (e.g. 32032928889998887776) and have an image generated with the name 'code'_qr.jpg and saved in a resource folder to be attached to an email that my program will send out.
How would I do this, does anyone know?
And while I'm asking (not so important that I get this answer now) but how would I implement QR code reading in, to get that code back, from a web cam? Thanks.
If you just need to write the data from the URL to a file, you can open up a stream, read from the file, and simply write the data to disk -- just remember to use the same extension (.jpg in this instance.)
Note that you could also simply send the link in the email (or post it as an inline image in the email.) If you really, really want to write it to disk and send it as attachment in your production system, the first-class solution for Ruby image processing is ruby-vips or ImageMagick.
Finally, since it's a disk operation, you're going to want to do it outside the normal web request cycle -- you're probably best off farming the operation out with delayed_job, or at the very least triggering the process with an AJAX request. Both of these give you the advantage that you can present a progress bar for the operation.