Class: Webservice::ResponseHandler

Inherits:
Object
  • Object
show all
Defined in:
lib/webservice/base/response_handler.rb

Defined Under Namespace

Classes: Tabular

Instance Method Summary collapse

Constructor Details

#initialize(app) ⇒ ResponseHandler

Returns a new instance of ResponseHandler.



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# File 'lib/webservice/base/response_handler.rb', line 11

def initialize( app )
  @app = app
end

Instance Method Details

#as_json(obj, opts = {}) ⇒ Object 



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# File 'lib/webservice/base/response_handler.rb', line 179

def as_json( obj, opts={} )
  if obj.respond_to? :as_json_v3     ## try (our own) serializer first
    obj.as_json_v3
  elsif obj.respond_to? :as_json_v2     ## try (our own) serializer first
    obj.as_json_v2
  elsif obj.respond_to? :as_json     ## try (activerecord) serializer
    obj.as_json
  else
    obj   ## just try/use as is
  end
end

#as_tabular(obj, opts = {}) ⇒ Object

auto-generate/convert “magic”



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# File 'lib/webservice/base/response_handler.rb', line 98

def as_tabular( obj, opts={} )
   headers = []
   headers_clone = []  ## keep an unmodified (e.g. with symbols not string) headers/keys clone
   rows    = []
   errors  = []

   if obj.respond_to? :to_a    ### convert activerecord relation to array (of records)
     recs = obj.to_a
   elsif obj.is_a? Array
     recs = obj
   else
     ## return as is; cannot convert
     ##   todo/fix: handle cannot convert different (e.g. except etc.) - why? why not??
     puts "!!!! [as_tabular] sorry; can't convert <#{obj.class.name}> - Array or to_a method required"
     return obj
   end


     recs.each do |rec|
       puts "rec #{rec.class.name}"
       if rec.respond_to? :as_row
         row = rec.as_row
         rows << row.values   ## add rows as is 1:1
       elsif rec.respond_to?( :as_json_v3 ) ||
             rec.respond_to?( :as_json_v2 ) ||
             rec.respond_to?( :as_json )    ||
             rec.is_a?( Hash )   ## allow (plain) hash too  - give it priority (try first?) - why? why not??

         if rec.respond_to? :as_json_v3
             row = rec.as_json_v3
         elsif rec.respond_to? :as_json_v2
             row = rec.as_json_v2
         elsif rec.respond_to? :as_json
             row = rec.as_json
         else
             row = rec    ## assume it's already a hash (with key/value pairs)
         end

         ##  convert nested values e.g. array and hash to strings
         values = row.values.map do |value|
           if value.is_a? Hash
             ## todo: use our own "pretty printer" e.g. use unqouted strings - why? why not?
             value.to_json  ## use to_json "key": "value" instead of :key => "value"
           elsif value.is_a? Array
             ## todo: use our own "pretty printer" e.g. use unqouted strings - why? why not?
             ## value = "[#{value.join('|')}]" ## use | for joins (instead of ,) - why? why not?? keep comma(,) - why? why not??
             value.to_json
           else
             value
           end
         end
         pp values
         rows << values
       else
          ## todo: add record index - why? why not?
          puts "sorry; can't convert - as_row or as_json method or hash required"
          errors << "sorry; can't convert <#{rec.class.name}> - as_row or as_json method or hash required"
          next
       end

       ## check headers - always must match!!!!!!!
       if headers.empty?
         headers_clone = row.keys
         pp headers_clone
         headers = headers_clone.map { |header| header.to_s }
         pp headers
       else
         ## todo: check if headers match!!!
       end
     end  # recs.each

  if errors.empty?
    Tabular.new( headers, rows )
  else   ## return row of errors
    ##  return errors as a (simple) multi-line string - why? why not??
    errors.join( "\n" )
  end

end

#content_type(type = nil) ⇒ Object

delegate some helpers too



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# File 'lib/webservice/base/response_handler.rb', line 23

def content_type( type=nil )  @app.content_type( type ); end

#env ⇒ Object 



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# File 'lib/webservice/base/response_handler.rb', line 20

def env()       @app.env;       end

#handle_response(obj, opts = {}) ⇒ Object

todo: add as_json like opts={} why? why not?



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# File 'lib/webservice/base/response_handler.rb', line 28

def handle_response( obj, opts={} )
  puts "[Webservice::Handler#handle_response (#{request.path_info}) params: #{params.inspect}] - obj : #{obj.class.name}"
  pp obj

  ## "magic" param format; default to json
  format = params['format'] || 'json'

  ## note: response.body must be (expects) an array!!!
  ##   thus, [json] etc.

  if format == 'csv'  || format == 'txt' ||
     format == 'html' || format == 'htm'

    data = as_tabular( obj )

    if data.is_a? Tabular
      if format == 'csv'  || format == 'txt'
         content_type :txt   ## use csv content type - why? why not??
         response.body = [data.to_csv]
      else
        ## assume html
        content_type :html
        response.body = [data.to_html_table]
      end
    else
      ## wrong format (expected Tabular from as_tabular - cannot convert)
      ##   todo: issue warning/notice about wrong format - how?
      ##   use different http status code - why? why not??
      content_type :txt
      ##  todo/check: use just data.to_s  for all - why? why not?
      ## for now return as is (convert to string with to_s or inspect)
      response.body = [data.is_a?( String ) ? data.to_s : data.inspect]
    end
  else    ## default/assume json
    data = as_json( obj )

    ## note: hash or array required!!! for now for json generation
    #   hash   => single record
    #   array  => multiple records (that is, array of hashes)

    if data.is_a?( Hash ) || data.is_a?( Array )
      json = JSON.pretty_generate( data )   ## use pretty printer

      callback = params.delete( 'callback' )

      if callback
        content_type :js
        response.body = ["#{callback}(#{json})"]
      else
        content_type :json
        response.body = [json]
      end
    else
       ## todo/fix/check: change http status to unprocessable entity
       ##   or something --  why ??? why not??
       ##
       ##  allow "standalone" number, nils, strings - why? why not?
       ##   for now valid json must be wrapped in array [] or hash {}
       content_type :txt
       ##  todo/check: use just data.to_s  for all - why? why not?
       ## for now return as is (convert to string with to_s or inspect)
       response.body = [data.is_a?( String ) ? data.to_s : data.inspect]
    end
  end
end

#params ⇒ Object 



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# File 'lib/webservice/base/response_handler.rb', line 19

def params()    @app.params;    end

#request ⇒ Object

delegate request, response, params, env

todo/fix: use def_delegate - why? why not???



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# File 'lib/webservice/base/response_handler.rb', line 17

def request()   @app.request;   end

#response ⇒ Object 



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# File 'lib/webservice/base/response_handler.rb', line 18

def response()  @app.response;  end