CODEWITHSUNDEEP
rubyregexsubstring
Hommer Smith
Hommer Smith

Reputation: 27852

Check if string contains any substring in an array in Ruby

I am using the Tmail library, and for each attachment in an email, when I do attachment.content_type, sometimes I get not just the content type but also the name. Examples:

image/jpeg; name=example3.jpg

image/jpeg; name=example.jpg

image/jpeg; name=photo.JPG

image/png

I have an array of valid content types like this:

VALID_CONTENT_TYPES = ['image/jpeg']

I would like to be able to check if the content type is included in any of the valid content types array elements.

What would be the best way of doing so in Ruby?

Upvotes: 51

Views: 68943

Answers (6)

Inversion
Inversion

Reputation: 1240

I use the next helper:

class String

    # line.includes_any? ['keyword_1', 'keyword_2']
    # line.includes_any? 'keyword_1', 'keyword_2'
    def includes_any?(*arr)
        arr.flatten.any? { self.include? _1 }
    end

end

Upvotes: 0

bonafernando
bonafernando

Reputation: 1159

I think we can divide this question in two:

  1. How to clean undesired data
  2. How to check if cleaned data is valid

The first is well answered above. For the second, I would do the following:

(cleaned_content_types - VALID_CONTENT_TYPES) == 0

The nice thing about this solution is that you can easily create a variable to store the undesired types to list them later like this example:

VALID_CONTENT_TYPES = ['image/jpeg']
cleaned_content_types = ['image/png', 'image/jpeg', 'image/gif', 'image/jpeg']

undesired_types = cleaned_content_types - VALID_CONTENT_TYPES
if undesired_types.size > 0
  error_message = "The types #{undesired_types.join(', ')} are not allowed"
else
  # The happy path here
end

Upvotes: 0

noob
noob

Reputation: 9202

# will be true if the content type is included    
VALID_CONTENT_TYPES.include? attachment.content_type.gsub!(/^(image\/[a-z]+).+$/, "\1")

Upvotes: 2

angusiguess
angusiguess

Reputation: 639

So if we just want existence of a match: 

VALID_CONTENT_TYPES.inject(false) do |sofar, type| 
    sofar or attachment.content_type.start_with? type
end

If we want the matches this will give the list of matching strings in the array:

VALID_CONTENT_TYPES.select { |type| attachment.content_type.start_with? type }

Upvotes: 3

Simon Bagreev
Simon Bagreev

Reputation: 2859

If image/jpeg; name=example3.jpg is a String:

("image/jpeg; name=example3.jpg".split("; ") & VALID_CONTENT_TYPES).length > 0

i.e. intersection (elements common to the two arrays) of VALID_CONTENT_TYPES array and attachment.content_type array (including type) should be greater than 0.

That's at least one of many ways.

Upvotes: 3

cydparser
cydparser

Reputation: 2087

There are multiple ways to accomplish that. You could check each string until a match is found using Enumerable#any?:

str = "alo eh tu"
['alo','hola','test'].any? { |word| str.include?(word) }

Though it might be faster to convert the array of strings into a Regexp:

words = ['alo','hola','test']
r = /#{words.join("|")}/ # assuming there are no special chars
r === "alo eh tu"

Upvotes: 124

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