Class: ApiQueryProvider::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/api-query-provider/base.rb

Overview

This class serves as a base class for any API Requests, it has several settings: api_url: sets the base url requests are made to_sym api_path: sets the path specific to this class, can contain replaceable elements data_selector: if the data is wrapped in an object, you can define a Proc taking the parsed response as Hash and returning a portion of that Hash for further parsing the keys are Strings. Be aware that if the data contains any fields named like a ruby internal method or field, it will be shadowed if you define it explicitly, it autogeneration is enabled, the name will have a underscore appended.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(data) ⇒ Base

basic parsing constructor takes the json data and tries to assign it to attr_accessor methods make sure to define them for any field present in the response



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# File 'lib/api-query-provider/base.rb', line 73

def initialize(data)
  if self.class == ApiQueryProvider::Base
    raise "this class should never be instanciated directly"
  end
  
  @provided_symbols = []

  data.each do |key, value|
    @provided_symbols << key.to_sym
         
    key = self.class.shadow key
  
    if !self.respond_to? key.to_sym
      if self.class.autogenerate
        self.class.class_eval do
          attr_accessor key.to_sym
        end
      else
        raise "field not found: #{key}. Either enable auto generation or add attr_accessor :#{key}"
      end
    end

    if self.class.custom_fields.include? key.to_sym
      value = self.class.custom_fields[key.to_sym].call(value)
    end
    
    self.send("#{key}=".to_sym, value)
  end
end

Instance Attribute Details

#provided_symbols ⇒ Object (readonly)

Returns the value of attribute provided_symbols.



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# File 'lib/api-query-provider/base.rb', line 67

def provided_symbols
  @provided_symbols
end

Class Method Details

.api_path ⇒ Object 



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# File 'lib/api-query-provider/base.rb', line 21

def self.api_path
  @api_path
end

.api_path=(value) ⇒ Object 



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# File 'lib/api-query-provider/base.rb', line 25

def self.api_path= (value)
  @api_path = value
end

.api_url ⇒ Object 



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# File 'lib/api-query-provider/base.rb', line 13

def self.api_url
  @api_url
end

.api_url=(value) ⇒ Object 



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# File 'lib/api-query-provider/base.rb', line 17

def self.api_url= (value)
  @api_url = value
end

.autogenerate ⇒ Object 



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# File 'lib/api-query-provider/base.rb', line 41

def self.autogenerate
  if @autogenerate.nil?
    false
  else
    @autogenerate
  end
end

.autogenerate=(value) ⇒ Object 



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# File 'lib/api-query-provider/base.rb', line 49

def self.autogenerate= (value)
  @autogenerate = value
end

.custom_field(field, &block) ⇒ Object 



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# File 'lib/api-query-provider/base.rb', line 53

def self.custom_field(field, &block)
  @custom_fields ||= {}
  
  @custom_fields[field.to_sym] = block.to_proc
end

.custom_fields ⇒ Object 



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# File 'lib/api-query-provider/base.rb', line 59

def self.custom_fields
  @custom_fields || {}
end

.data_selector ⇒ Object 



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# File 'lib/api-query-provider/base.rb', line 33

def self.data_selector
  @data_selector || Proc.new { |e| e }
end

.data_selector=(value) ⇒ Object 



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# File 'lib/api-query-provider/base.rb', line 37

def self.data_selector= (value)
  @data_selector = value
end

.interface ⇒ Object 



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# File 'lib/api-query-provider/base.rb', line 136

def self.interface
  ApiQueryProvider::Provider.new(self)
end

.limit(count) ⇒ Object 



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# File 'lib/api-query-provider/base.rb', line 144

def self.limit(count)
  interface.limit(count)
end

.required_symbols ⇒ Object 



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# File 'lib/api-query-provider/base.rb', line 29

def self.required_symbols
  @api_path.scan(/:(\w+)/).flatten.map { |e| e.to_sym } - ApiQueryProvider::Provider.system_symbols
end

.select(*fields) ⇒ Object 



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# File 'lib/api-query-provider/base.rb', line 148

def self.select(*fields)
  interface.select(fields)
end

.shadow(key) ⇒ Object 



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# File 'lib/api-query-provider/base.rb', line 63

def self.shadow(key)
  key.to_sym == :class ? "class_".to_sym : key
end

.where(opt = {}) ⇒ Object 



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# File 'lib/api-query-provider/base.rb', line 140

def self.where(opt = {})
  interface.where(opt)
end

Instance Method Details

#extend ⇒ Object 



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# File 'lib/api-query-provider/base.rb', line 103

def extend
  if !(self.class.required_symbols - provided_symbols).empty?
    raise "not all needed values are present"
  end
  
  request = self.class.where
  
  self.class.required_symbols.each do |sym|
    request = request.where(sym => self.send(self.class.shadow(sym).to_sym))
  end
  
  response = request.execute
  
  if response.count != 1
    raise "the request did not return exactly one element"
  end
  
  response.first 
end

#extend! ⇒ Object 



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# File 'lib/api-query-provider/base.rb', line 123

def extend!
  local = self.extend
  
  local.provided_symbols.each do |symbol|
    shadow = self.class.shadow(symbol).to_sym
    self.send("#{shadow}=".to_sym, local.send("#{shadow}".to_sym))
  end
  
  @provided_symbols = local.provided_symbols
  
  self
end