Class ContentCallback
In: app/models/content_callback.rb
Parent: ActiveRecord::Base

API for interaction with the database table ‘content_callbacks’, and it‘s related data model.

Callback Modules

Callback modules are specific to a project host, because each content type is defined for a project host.

All project specific callback libraries use the same file name, as specified by the constant CONTENT_CALLBACK_LIB. These libraries are stored within a project‘s library directory:

  • hosts/<project id>/lib/<CONTENT_CALLBACK_LIB>

Callback Methods

Callback fields map to callback methods using their content type database id and content callback database id:

  • callback_<content type id>_<content callback id>

For example, the content callback method with content type id = 47 and content callback id = 2 would be named:

  • callback_47_2()

This naming convention increases portability, stability, and maintainability; a content type‘s name and content callback field‘s name may be changed without impacting the callback method.

Methods

get   last_modified  

Public Class methods

get( project_id, project_host_id, content_type_id, content_item )

Retrieve all callback fields defined for a content type, process their corresponding methods, and return their values.

[Source]

    # File app/models/content_callback.rb, line 36
36:   def self.get (
37:     project_id,
38:     project_host_id,
39:     content_type_id,
40:     content_item
41:   )
42:     # Values of all callback fields for this content item, indexed by field 
43:     # name.
44:     fields = {}
45: 
46: 
47:     # If this project's callback library is available then process callbacks.
48:     if (load_project_library(project_host_id, CONTENT_CALLBACK_LIB))
49:       # Retrieve and process all callbacks.
50:       for callback in find_all_by_project_id_and_content_type_id_and_active(
51:                                                                 project_id,
52:                                                                 content_type_id,
53:                                                                 'TRUE')
54:         # Construct the name of this callback field's method.
55:         method_name = "callback_#{content_type_id}_#{callback.id}"
56: 
57:         # Obtain the value for this callback field, by processing the current
58:         # content item using this field's callback method. 
59:         begin
60:           value = FALSE
61:           eval "value = #{method_name}(project_host_id, 
62:                                        content_type_id, 
63:                                        content_item)"
64:           if (value)
65:             fields[callback.field] = value.to_s
66:           else
67:             fields[callback.field] = FALSE
68:           end
69:         rescue
70:           l(m(3, method_name, callback.field))
71:         end
72:       end
73:     end
74: 
75: 
76:     # Return all fields and values.
77:     fields
78:   end
last_modified( content_type_ids )

Determine the maximum value of the ‘updated_on’ field for this table, comparing the values of all rows for this project host.

[Source]

    # File app/models/content_callback.rb, line 85
85:   def self.last_modified (
86:     content_type_ids
87:   )
88:     max = Time.at(0)
89: 
90:     for content_type_id in content_type_ids
91:       for callback in find_all_by_content_type_id_and_active(content_type_id, 
92:                                                              TRUE)
93:         max = callback.updated_on if (callback.updated_on > max)
94:       end
95:     end
96: 
97:     max
98:   end

[Validate]