How can we paginate a big hash? - ruby

Question

I have a pure ruby hash like the following one:
"1875": {
"child1": {
"field1": 1875,
"field2": "Test1"
},
"child2": {
"field1": "value1",
"field2": "value2"
}
},
"1959": {
"child1": {
"field1": 1875,
"field2": "Test1"
},
"child2": {
"field1": "value1",
"field2": "value2"
}
}
I have so many keys that follow the above structure that I want to paginate it.
I have tried the following code:
#records = #records.t_a.paginate(page: params[:page], per_page: 5)
But it is returning me all the elements in an array, like this:
["1875", {
"child1": {
"field1": 1875,
"field2": "Test1"
},
"child2": {
"field1": "value1",
"field2": "value2"
}
}
]
["1959", {
"child1": {
"field1": 1875,
"field2": "Test1"
},
"child2": {
"field1": "value1",
"field2": "value2"
}
}
]

Answer 1

First of all, note that a Hash is a dictionary-like collection and order shouldn't mater. So if you need to use pagination most likely a hash is the wrong data structure to use and you should use something like an array.
#records.t_a.paginate(page: params[:page], per_page: 5) returns an array because you are converting the hash to array with to_a. Depending what you are using the hash/pagination for this may be enough. For example, to display a the returned records assuming there is a function for printing child:
#records.t_a.paginate(page: params[:page], per_page: 5).each |key, value| do
<h1><%= book.title %></h1>
<p>print_child(value)</p>
If you really want a hash, you can convert the Array back to a hash:
Hash[#records.t_a.paginate(page: params[:page], per_page: 5)]