As we mentioned before in this specification, an IMS LD document is an XML file, so by practical means, we are just dealing with an XML file, which is easy to parse. In this XML file is defined all the unit of learning. We took advantage of the work already done in the assessment package, where an IMS QTI parser was implemented. In the case of the assessment package, the document follows the IMS QTI specification, and it is parsed and imported into the data base. The imsld package will do something similar but with documents following the IMS LD specification, and with the big difference that the MS LD document can not be displayed in only one .LRN package, as happens with IMS QTI. IMS LD deals with activities, roles (users), properties, conditions, workflows, etc, and that is why the imsld package will interact with other .LRN services.
Besides the XML parser, we need .LRN to recognize each one of the activities and roles defined in the IMS LD and to know what to do with each one of them.
The professor or IMS LD designer will only have to enter a path where it is located an IMS LD file and then push upload. By these way a profesor can upload an existing IMS LD file which describes a unit of learning. The IMS LD importer will recognize IMS LD files that are integrated in IMS CP or files that are IMS LD, but are not in an IMS CP.
We call the process of parsing and interpreting the IMS LD document the import stage. This IMS LD document can be generated with any external or internal editor that follows the IMS LD specification, such as LAMS, Coppercore, Reload, etc, wich is one of the main advantages and purposes of following a well defined standNoard.
The IMS-LD package is a .LRN service (or package, we use these terms + indifferently in this specification when referring to .LRN), which will + interact with some other .LRN services. When writing this specification, + we expect the IMS-LD package to interact with at least the following .LRN + packages:
Forums.
Jabber.
Assessment.
Evaluation (grade book).
Calendar.
News.
FAQ
Notifications.
File Storage.
As we mentioned earlier, the IMS-LD package allows to easily modify + the mappings between the elements of the IMS-LD specification and the .LRN + services. And not only modifying the mappings, but also to add new ones. + By these way if the IMS-LD specification change in some aspect, then the + package will adapt to the new changes easily. From our point of view it is + necessary that in the future the IMS-LD specification adds more tags that + map onto services. By these way compatibility between LMS are obtained, + and if an LMS doesn't understand one tag because it is not available, then + it will be ignored and nothing will be presented to the user.
Besides, we take advantage of the new callbacks used in OpenACS in + order to provide a clean interaction between different .LRN packages. With + the callbacks we can determine if some needed package is not installed, + and instead of displaying an error to the user, try to map the activity or + whatever we are mapping to other package, and if after trying with all the + available packages we can't map the item to .LRN, a message is shown to + the user with this and any other item that could not be mapped by the + system and with the purpose of letting the user to do the manual + mapping.
We have to take into account that the item will not always have all + the necessary information to let the mapping be done easily, but we try to + do our best by providing at least the required information to create the + forum, chat, assessment, task, etc, and if definitively no mapping can be + done, a final error message is shown to the user indicating that there is + at least one item that .LRN can't understand.