how to render Ruby array as JavaScript array in ERB template [duplicate] - ruby-on-rails

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Use ruby array for a javascript array in erb. Escaping quotes
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Closed 7 years ago.
I need to render a Ruby array in a very specific format for an erb template. This is because I am using JQcloud to build word clouds using JQuery, and is apparently picky about array formatting.
Here is the way that JQcloud requires a JS array to be formatted:
var word_array = [
{text: "Lorem", weight: 15},
{text: "Ipsum", weight: 9},
{text: "Dolor", weight: 6},
{text: "Sit", weight: 7},
{text: "Amet", weight: 5}
// ...as many words as you want
];
So what I have created in my controller are two arrays, one array of words to build my cloud, and another array of weights for each word.
ruby_word_array = ["Lorem","Ipsum","Dolor","Sit","Amet"]
ruby_weight_array = [15,10,13,8,4]
I need to convert my two Ruby arrays in such a way that they render properly with erb. So far I have come up with:
var wordArray = <%= raw #word_array.map{|a, i| {text: #word_array[0], weight: 15} } %> # I just hard coded the weight for simplicity
This gives me something that's close, but not close enough, and it ends up formatted like so:
var wordArray = [{:text=>"Lorem", :weight=>15}, {:text=>"Ipsum", :weight=>15}]
I really just need to know how to modify my last example to render in the Python style hash syntax {key: "value"},{key_2: "value_2"}
This is honestly a tricky one and I am stumped. The library I am using for this is called JQcloud, and it has a Ruby gem which I have incorporated into this Rails app. Here is a link.

Answer 1

Why don't your just use to_json?
# in ruby
#array = [{:text=>"Lorem", :weight=>15}, {:text=>"Ipsum", :weight=>15}]
Then, in the view:
var wordArray = <%= #array.to_json.html_safe %>;
Which will render:
var wordArray = [{"text":"Lorem","weight":15},{"text":"Ipsum","weight":15}];

Answer 2

You should create a helper function in app/helpers that does the behaviour you want. It's better to leave complex logic out of the view. Then in the view
var wordArray = <%= myHelper #word_array %>
And in the helper
def myHelper(word_array):
string = "["
word_array.each do |word|
string << "{text: \"#{word[:text]}\", weight: #{word[:weight]}},"
string = string.chomp(",") #in case JS hates the last comma
string << "]"
return string
Really, though, you can put anything you want in myHelper. You could pass both arrays and put them together in the helper. You could add newlines to the strings. Anything is possible

Answer 3

In such 2 Arrays situation, zip is useful.
ruby_word_array.zip(ruby_weight_array).map{|word, weight| "{text: #{word}, weight: #{weight}}"}.join(',')
If you need [],
'[' + ruby_word_array.zip(ruby_weight_array).map{|word, weight| "{text: #{word}, weight: #{weight}}"}.join(',') + ']'