I am trying to do something quite simple using Sinatra and RMagick.
Take a image, through a simple form
file upload
Use RMagick to resize it
Then store it in a database for
persistence (irrelevant)
But after going through the RDocs and endless head banging testing
I can't seem to get the form image to a RMagick object cleanly.
This is the horrible thing that is currently working for me:
def image_resize(img_data)
filecount = rand
writer = File.new("/tmp/#{filecount}.jpg", "w")
writer.puts(img_data)
writer.close
resized_image = Magick::ImageList.new("/tmp/#{filecount}.jpg").first
resized_image.crop_resized!(100,100, Magick::NorthGravity)
resized.format = 'jpeg'
resized_image.to_blob
end
#call the method with my form image data
image_resize(params[:image][:tempfile].read)
So how do I do the obvious right thing and just stick my form image data straight into a RMagick object without having to write and read the disk.
I have tried various ways of reading in Magick::Image and ImageLists but have only got an abundance of errors barfed at me.
Thanks for any kind of direction
-1.2.
You need to get the path from the tempfile and pass that to Magick::Image’s read.
Here’s an example:
post "/upload-photo" do
image = Magick::Image.read(params[:image][:tempfile].path)[0]
image.crop_resized! 100, 100, Magick::CenterGravity
store_image_data image.to_blob
redirect "/done"
end
Or you can read straight from the ActionDispatch::Http::UploadedFile like so:
image = Magick::Image.from_blob(params[:image].read)
Related
I am using prawnpdf/pdf-inspector to test that content of a PDF generated in my Rails app is correct.
I would want to check that the PDF file contains a link with certain URL. I looked at yob/pdf-reader but haven't found any useful information related to this topic
Is it possible to test URLs within PDF with Ruby/RSpec?
I would want the following:
expect(urls_in_pdf(pdf)).to include 'https://example.com/users/1'
The https://github.com/yob/pdf-reader contains a method for each page called text.
Do something like
pdf = PDF::Reader.new("tmp/pdf.pdf")
assert pdf.pages[0].text.include? 'https://example.com/users/1'
assuming what you are looking for is at the first page
Since pdf-inspector seems only to return text, you could try to use the pdf-reader directly (pdf-inspector uses it anyways).
reader = PDF::Reader.new("somefile.pdf")
reader.pages.each do |page|
puts page.raw_content # This should also give you the link
end
Anyway I only did a quick look at the github page. I am not sure what raw_content exactly returns. But there is also a low-level method to directly access the objects of the pdf:
reader = PDF::Reader.new("somefile.pdf")
puts reader.objects.inspect
With that it surely is possible to get the url.
I am new to the Google App Engine and I am trying to use the Blobstore to store images that I want to display later on.
The image storage works fine. Now I want to dynamically change some images in my html code. Therefore I need a method of getting the images out of the blobstore and passing them. I am using Python. I found the get_serving_url-command, which seemed to be the perfect fit. Sadly, this causes an Error and I seem to be unable to fix it.
My basic code looks like this:
blob_key = "yu343mQ7kT4344N434ewQ=="
if blob_key:
blob_info = blobstore.get(blob_key)
if blob_info:
img = images.Image(blob_key=blob_key)
url = images.get_serving_url(blob_key)
...
Everytime the function gets called, I get the following Error in my Log Console.
File "C:\Program Files
(x86)\Google\google_appengine\google\appengine\ext\remote_api\remote_api_stub.py",
line 234, in _MakeRealSyncCall
raise pickle.loads(response_pb.exception())
AttributeError: 'ImagesNotImplementedServiceStub' object has no
attribute 'THREADSAFE'
I have no idea how to fix it or if I am doing something terribly wrong.
I am very grateful for your support! Thank you in advance!
Have a nice day
You probably need an instance of BlobKey so if you are getting blob_info successfully try:
img = images.Image(blob_key=blob_info.key())
url = images.get_serving_url(blob_info.key())
Im scraping a website using Celerity gem and I want to save an image but I dont know how to do it XD
With the next Celerity command I get an IO object
irb(main):260:0* image = #browser.image(:xpath, ".//*[#class='notdTop']/img").download
=> #<IO:0x277e07ae>
How can I save this object to a jpg file?? I tried this, but didnt work:
irb(main):261:0> image.flush
IOError: not opened for writing
but the IO object is not closed because I got this:
irb(main):264:0> image.closed?
=> false
Anyone can help me please?
Try:
image.save(filename)
http://rubydoc.info/gems/celerity/0.8.9/Celerity/Image#save-instance_method
Does anyone have any insights into using CarrierWave with an ActiveResource model (in Rails 3)? I've got an ActiveResource model with field for the filename, and I want to save the file to the remote filesystem.
I've tried a few things without much success (or conviction that I was doing anything remotely correctly), so I'd appreciate suggestions from anyone who's successfully implemented CarrierWave without using the ORM modules already included in the gem.
I'm probably late for this as the original author has moved on, but this question comes up at the top when someone searches for "carrierwave activeresource", so I thought it was still worth answering.
For the sake of discussion, let's assume we have a model named Artist with a picture named artist_picture mounted as a CarrierWave uploader. With ActiveRecord, you would assign this picture to a File:
artist.artist_picture=File.open('ravello.jpg')
And when you save artist:
artist.save!
the picture will be saved, also.
Now, let's say I create a resource based on this:
class Artist < ActiveResource::Base
end
If I subsequently read in an artist:
artist = Artist.find(1)
and look at it, I'll find this in there:
#<Artist:0x39432039 #attributes={"id"=>1, "name"=>"Ravello", "artist_picture"=>#<ArtistPicture:0x282347249243 #attributes={"url"=>"/uploads/artists/artist_picture/1/ravello.jpg"}, #prefix_options={}, #persisted=false>, #prefix_options={}, #persisted=false>
Interestingly, artist_picture is itself a model and we could declare it and play around with it if we wanted. As it is, you can use the url to grab the picture if you want. But let's talk instead about uploading another picture.
We can add this little bit of code to the Artist model on the server side:
def artist_picture_as_base64=(picsource)
tmpfile = Tempfile.new(['artist','.jpg'], Rails.root.join('tmp'), :encoding => 'BINARY')
begin
tmpfile.write(Base64.decode64(picsource.force_encoding("BINARY")))
file = CarrierWave::SanitizedFile.new(tmpfile)
file.content_type = 'image/jpg'
self.artist_picture = file
ensure
tmpfile.close!
end
end
I'm just showing a simple example - you should probably pass the original filename, also. Anyway, on the resource side:
class Artist < ActiveResource::Base
def artist_picture=(filename)
self.artist_picture_as_base64=Base64.encode64(File.read(filename))
end
end
At this point, on the resource side you need only set "artist_picture" to a filename and it will be encoded and sent when the resource is saved. On the server side, the file will be decoded and saved. Presumably you could skip base64 encoding by just forcing the string to binary encoding, but it craps when I do that and I don't have the patience to track it down. Encoding as base64 works.
I wrote a simple Sinatra app that generate an image using rmagick from some user inputs. The image is saved in the ./public directory with a unique file name. The unique file name is used in the HTML generated by Sinatra so that each user gets the correct image. Once a day a script deletes files older than one hour. This is clearly a terrible hack but I have no web experience!
Is there any way to serve the rmagick image in sinatra without first saving it to disk?
Use the Image#to_blob method to turn the in-memory image into a string:
get '/' do
content_type 'image/png'
img = Magick::Image.read('logo:')[0]
img.format = 'png'
img.to_blob
end