Class: OMF::Web::DataSourceProxy

Inherits:
Common::LObject show all
Defined in:
lib/omf-web/data_source_proxy.rb

Overview

This object maintains synchronization between a JS DataSource object in a web browser and the corresponding OmlTable in this server.

Constant Summary collapse

@@datasources = 
{}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Common::Loggable

#_logger, #debug, #error, #fatal, #info, init_log, logger, set_environment, #warn

Constructor Details

#initialize(name, data_source) ⇒ DataSourceProxy

Returns a new instance of DataSourceProxy.



161
162
163
164
 
# File 'lib/omf-web/data_source_proxy.rb', line 161

def initialize(name, data_source)
  @name = name
  @data_source = data_source
end

Instance Attribute Details

#name ⇒ Object (readonly)

Returns the value of attribute name.



102
103
104
 
# File 'lib/omf-web/data_source_proxy.rb', line 102

def name
  @name
end

Class Method Details

.[](name) ⇒ Object 



38
39
40
41
42
43
44
45
46
47
48
 
# File 'lib/omf-web/data_source_proxy.rb', line 38

def self.[](name)
  name = name.to_sym
  unless dsp = OMF::Web::SessionStore[name, :dsp]
    if ds = @@datasources[name]
      dsp = OMF::Web::SessionStore[name, :dsp] = self.new(name, ds)
    else
      warn "Requesting unknown datasource '#{name}', only know about '#{@@datasources.keys.join(', ')}'."
    end
  end
  dsp
end

.for_source(ds_descr) ⇒ Object

Return proxies for ‘ds_name’. Note, there can be more then one proxy be needed for a datasource, such as a network which has one ds for the nodes and one for the links

@return: Array of proxies

TODO: This seems to hardcode networks.



58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
 
# File 'lib/omf-web/data_source_proxy.rb', line 58

def self.for_source(ds_descr)
  #raise "FOO #{ds_descr.inspect}"
  unless ds_descr.is_a? Hash
    raise "Expected Hash, but got '#{ds_descr.class}::#{ds_descr.inspect}'"
  end
  unless ds_name = ds_descr[:name]
    raise "Missing 'name' attribute in datasource description. (#{ds_descr.inspect})"
  end
  ds_name = ds_name.to_sym
  ds = @@datasources[ds_name]
  unless ds
    top = "#{ds_name}/"
    names = @@datasources.keys.find_all { |ds_name| ds_name.to_s.start_with? top }
    unless names.empty?
      return names.map do |ds_name| 
        OMF::Web::SessionStore[ds_name, :dsp] ||= self.new(ds_name, @@datasources[ds_name]) 
      end
    end
    # debug ">>>> #{dsa}"
    # # let's check for sub table, such as network/nodes
    # main, sub = ds_descr[:name].split('/')
    # if (sub)
      # if ds_top = @@datasources[main.to_sym]
        # ds = ds_top[sub.to_sym]
      # end
    # end
    unless ds
      raise "Unknown data source '#{ds_name}' (#{@@datasources.keys.inspect})"
    end
  end
  if ds.is_a? Hash
    raise "Is this actually used anywhere?"
    proxies = ds.map do |name, ds|
      id = "#{ds_name}_#{name}".to_sym
      proxy = OMF::Web::SessionStore[id, :dsp] ||= self.new(id, ds)
    end
    return proxies
  end
  
  #debug ">>>>> DS: #{ds_descr.inspect} - #{ds}"
  proxy = OMF::Web::SessionStore[ds_name, :dsp] ||= self.new(ds_name, ds)
  return [proxy]
end

.register_datasource(data_source, opts = {}) ⇒ Object

Register a data source.

params data_source - Data source to register params opts:

name - Name to use instead of data source's native name



22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
 
# File 'lib/omf-web/data_source_proxy.rb', line 22

def self.register_datasource(data_source, opts = {})
  name = (opts[:name] || data_source.name).to_sym
  if (@@datasources.key? name)
    raise "Repeated try to register data source '#{name}'"
  end
  if data_source.is_a? OMF::OML::OmlNetwork
    raise "Register link and node table separately "
  end
    # dsh = data_source.to_tables(opts)
    # @@datasources[name] = dsh
  # else
    # @@datasources[name] = data_source
  # end
  @@datasources[name] = data_source      
end

Instance Method Details

#create_slice(col_name, col_value) ⇒ Object

Create a new data source which only contains a slice of the underlying data source



133
134
135
136
137
138
 
# File 'lib/omf-web/data_source_proxy.rb', line 133

def create_slice(col_name, col_value)
  ds = @data_source.create_sliced_table(col_name, col_value)
  dsp = self.class.new(ds.name, ds)
  def dsp.release; @data_source.release end
  dsp
end

#on_changed(offset, &block) ⇒ Object

Register callback to be informed of changes to the underlying data source. Call block when new rows are becoming available. Block needs ot return true if it wants to continue receiving updates.

offset: Number of records already downloaded



119
120
121
122
123
124
125
126
127
128
129
130
 
# File 'lib/omf-web/data_source_proxy.rb', line 119

def on_changed(offset, &block)
  ds = @data_source
  rows = ds.rows[(offset - ds.offset) .. -1]
  if rows && rows.length > 0
    debug "on_changed: sending #{rows.length}"
    block.call :added, rows
  end
  @data_source.on_content_changed(block.object_id) do |action, rows|
    #debug "on_changed: #{action}: #{rows.inspect}"
    block.call action, rows
  end
end

#on_update(req) ⇒ Object 



108
109
110
111
 
# File 'lib/omf-web/data_source_proxy.rb', line 108

def on_update(req)
  res = {:events => @data_source.rows}
  [res.to_json, "text/json"]
end

#reset ⇒ Object 



104
105
106
 
# File 'lib/omf-web/data_source_proxy.rb', line 104

def reset()
  # TODO: Figure out partial sending 
end

#to_javascript(opts = {}) ⇒ Object 



140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
 
# File 'lib/omf-web/data_source_proxy.rb', line 140

def to_javascript(opts = {})
  #puts "to_java>>>>> #{opts.inspect}"
  sid = Thread.current["sessionID"]
  opts = opts.dup
  opts[:name] = @name
  opts[:schema] = @data_source.schema.describe
  opts[:update_url] = "/_update/#{@name}?sid=#{sid}"
  opts[:sid] = sid
  unless opts[:slice] # don't send any data if this is a sliced one
    #opts[:rows] = @data_source.rows[0 .. 20]
    opts[:rows] = []
    opts[:offset] = @data_source.offset
  end
  #puts "to_java2>>>>> #{opts.inspect}"
  
  %{
    OML.data_sources.register(#{opts.to_json});
  }
 
end