struct URI::Params
inherits Struct

An ordered multi-value mapped collection representing generic URI parameters.

Included modules

Enumerable

Class methods

.build(&block : Builder -> ) : String

Builds an url-encoded URI form/query.

The yielded object has an add method that accepts two arguments, a key (String) and a value (String or Nil). Keys and values are escaped using URI.encode_www_form.

require "uri/params"

params = URI::Params.build do |form|
  form.add "color", "black"
  form.add "name", "crystal"
  form.add "year", "2012 - today"
end
params # => "color=black&name=crystal&year=2012+-+today"

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.encode(hash : Hash(String, String | Array(String)))

Returns the given key value pairs as a url-encoded URI form/query.

require "uri/params"

URI::Params.encode({"foo" => "bar", "baz" => ["quux", "quuz"]}) # => "foo=bar&baz=quux&baz=quuz"

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.encode(named_tuple : NamedTuple)

Returns the given key value pairs as a url-encoded URI form/query.

require "uri/params"

URI::Params.encode({foo: "bar", baz: ["quux", "quuz"]}) # => "foo=bar&baz=quux&baz=quuz"

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.parse(query : String

Parses an URI query and yields each key-value pair.

require "uri/params"

query = "foo=bar&foo=baz&qux=zoo"
URI::Params.parse(query) do |key, value|
  # ...
end

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.new(raw_params : Hash(String, Array(String)))

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.new

Returns an empty URI::Params.

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.parse(query : String) : self

Parses an URI query string into a URI::Params

require "uri/params"

URI::Params.parse("foo=bar&foo=baz&qux=zoo")
# => #<URI::Params @raw_params = {"foo" => ["bar", "baz"], "qux" => ["zoo"]}>

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Methods

#==(other : self)

#[](name)

Returns first value for specified param name.

require "uri/params"

params = URI::Params.parse("email=john@example.org")
params["email"]              # => "john@example.org"
params["non_existent_param"] # KeyError

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#[]=(name, value : String | Array(String))

Sets the name key to value.

require "uri/params"

params = URI::Params{"a" => ["b", "c"]}
params["a"] = "d"
params["a"]           # => "d"
params.fetch_all("a") # => ["d"]

params["a"] = ["e", "f"]
params["a"]           # => "e"
params.fetch_all("a") # => ["e", "f"]

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#[]?(name)

Returns first value or nil for specified param name.

params["email"]?              # => "john@example.org"
params["non_existent_param"]? # nil

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#add(name, value)

Appends new value for specified param name. Creates param when there was no such param.

params.add("item", "keychain")
params.fetch_all("item") # => ["pencil", "book", "workbook", "keychain"]

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#clone : self

Returns a copy of this URI::Params instance.

require "uri/params"

original = URI::Params{"name" => "Jamie"}
updated = original.clone
updated["name"] = "Ary"

original["name"] # => "Jamie"

Identical to #dup.

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#delete(name)

Deletes first value for provided param name. If there are no values left, deletes param itself. Returns deleted value.

params.delete("item")    # => "keychain"
params.fetch_all("item") # => ["keynote"]

params.delete("item") # => "keynote"
params["item"]        # KeyError

params.delete("non_existent_param") # KeyError

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#delete_all(name)

Deletes all values for provided param name. Returns array of deleted values.

params.set_all("comments", ["hello, world!", ":+1:"])
params.delete_all("comments") # => ["hello, world!", ":+1:"]
params.has_key?("comments")   # => false

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#dup : self

Returns a copy of this URI::Params instance.

require "uri/params"

original = URI::Params{"name" => "Jamie"}
updated = original.dup
updated["name"] = "Ary"

original["name"] # => "Jamie"

Identical to #clone.

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#each

Allows to iterate over all name-value pairs.

params.each do |name, value|
  puts "#{name} => #{value}"
end

# Outputs:
# email => john@example.org
# item => keychain
# item => keynote

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#empty?(*args, **options)

Returns true if params is empty.

URI::Params.new.empty?                              # => true
URI::Params.parse("foo=bar&foo=baz&qux=zoo").empty? # => false

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#empty?

Returns true if params is empty.

URI::Params.new.empty?                              # => true
URI::Params.parse("foo=bar&foo=baz&qux=zoo").empty? # => false

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#fetch(name, default)

Returns first value for specified param name. Falls back to provided default value when there is no such param.

params["email"] = "john@example.org"
params.fetch("email", "none@example.org")           # => "john@example.org"
params.fetch("non_existent_param", "default value") # => "default value"

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#fetch

Returns first value for specified param name. Falls back to return value of provided block when there is no such param.

params.delete("email")
params.fetch("email") { raise "Email is missing" }              # raises "Email is missing"
params.fetch("non_existent_param") { "default computed value" } # => "default computed value"

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#fetch_all(name)

Returns all values for specified param name.

params.set_all("item", ["pencil", "book", "workbook"])
params.fetch_all("item") # => ["pencil", "book", "workbook"]

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#has_key?

Returns true if param with provided name exists.

params.has_key?("email")   # => true
params.has_key?("garbage") # => false

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#has_key?(*args, **options)

Returns true if param with provided name exists.

params.has_key?("email")   # => true
params.has_key?("garbage") # => false

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#hash(hasher)

See Object#hash(hasher)

#set_all(name, values)

Sets all values for specified param name at once.

params.set_all("item", ["keychain", "keynote"])
params.fetch_all("item") # => ["keychain", "keynote"]

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#to_s(io : IO) : Nil

Serializes to string representation as http url-encoded form.

require "uri/params"

params = URI::Params.parse("item=keychain&item=keynote&email=john@example.org")
params.to_s # => "item=keychain&item=keynote&email=john%40example.org"

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