Download csv file ruby

See Options for Generating. Note that a passed String is modified by this method. This method has one additional option: :encoding , which sets the base Encoding for the output if no no str is specified. Returns the String created by generating CSV from ary using the specified options. This method accepts an additional option, :encoding , which sets the base Encoding for the output.

This method will try to guess your Encoding from the first non- nil field in row , if possible, but you may need to use this parameter as a backup plan.

For other options , see Options for Generating. Creates or retrieves cached CSV objects. For arguments and options, see ::new. Subsequent calls to instance with that same string or io retrieve that same cached object:.

A subsequent call to instance with a different string or io creates and caches a different CSV object. When a block is given, calls the block with the created or retrieved CSV object; returns the block's return value:.

Returns the new CSV object created using string or io and the specified options. Argument string should be a String object; it will be put into a new StringIO object positioned at the beginning.

For performance reasons, the options cannot be overridden in a CSV object, so those specified here will endure. See Delegated Methods. With a block given, calls the block with the created CSV object; returns the block's return value:. Argument options : see Options for Parsing. With no block given, returns a CSV::Table object formed from the source. With a block given, calls the block with each parsed row, which has been formed into a CSV::Row object:. Returns the data created by parsing the first line of string or io using the specified options.

With option headers , returns the first row as a CSV::Row object. Opens the given source with the given options see ::open , reads the source see read , and returns the result, which will be either an Array of Arrays or a CSV::Table. Calls ::read with source , options , and certain default options:. Returns an Array containing field converters; see Field Converters :.

Returns an Array containing header converters; used for parsing; see Header Converters :. Returns true if the next row to be read is a header row; false otherwise.

Returns the value that determines whether headers are used; used for parsing; see Option headers :. Home Core 3. Home Classes Methods. In Files csv. Parent Object. Included Modules Enumerable. Generating CSV data to a String object. To make CSV available: require 'csv' All examples here assume that this has been done.

Each inner Array is a row. Each String is a field. Method ::instance returns a new or cached CSV object. Methods included by module Enumerable. Methods delegated to class IO. See below. You may call: IO binmode binmode? Note that this setting will not skip rows that contain column separators, even if the rows contain no actual data. When setting an object responding to match , every line matching it is considered a comment and ignored during parsing.

When set to a String, it is first converted to a Regexp. When set to nil no line is considered a comment. If the passed object does not respond to match , ArgumentError is thrown. When setting a true value, CSV will attempt to parse input not conformant with RFC , such as double quotes in unquoted fields.

When setting a true value, CSV will quote empty values with double quotes. When false , CSV will emit an empty string for an empty field value. Converts values on each line with the specified Proc object s , which receive a String value and return a String or nil value.

When an array is specified, each converter will be applied in order. When a String value, nil value s on each line will be replaced with the specified value. When a String or nil value, empty value s on each line will be replaced with the specified value. If you specify a string instead of true , CSV will strip string. The length of the string must be 1. Options cannot be overridden in the instance methods for performance reasons, so be sure to set what you want here.

This is intended as the primary interface for writing a CSV file. You may also pass an optional Hash containing any options ::new understands as the final argument. Note : This is different from the Ruby 1. Use ::foreach for that behavior. CSV will check the Encoding of the underlying IO object set by the mode you pass to determine how to parse the data. You may provide a second Encoding to have the data transcoded as it is read just as you can with a normal call to IO::open.

You may call:. This method can be used to easily parse CSV out of a String. You may either provide a block which will be called with each row of the String in turn, or just use the returned Array of Arrays when no block is given. You pass your str to read from, and an optional options containing anything ::new understands. Note that if line contains multiple rows, anything beyond the first row is ignored. Pass the path to the file and any options ::new understands.

Passing a directory as a :destination option will save the file to that directory. This will give the downloaded file a random name generated by Tempfile. If you want to keep the name of the file from the URL you need to do a bit more work. In this case we can download the file to a Tempfile and then move it to a permanent location on our drive. For this we'll use FileUtils mv which takes two arguments, the file name and the destination we want to move it to.

Now we've downloaded the file safely and efficiently and stored it permanently on our hard drive. Down takes a bunch of other options too, to control the download experience. This stops attacker tying up your server with giant image downloads.

If you wanted to download a file that was at most 5MB in size with at most 5 redirects, you would use:. In this post we've seen how to download images using both open-uri and Down. Down is much safer as it saves us from infinite redirect loops and remote code injection, and it is more user friendly as it always returns a Tempfile and lets us easily restrict file size. Building intelligent escalation chains for modern SRE.

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Question feed. Stack Overflow works best with JavaScript enabled. The Rails controller is the logical center of your application. It coordinates the interaction between the user, the views, and the model. The controller is also a home to a number of important ancillary services.