Submit Comments to Pluck

UML Sequence Diagram Example

An example of sequence diagram which shows how user comments on some article are submitted to Pluck using various AJAX technologies. (See example of interaction overview diagram with similar semantics at Submit Comments to Pluck using DWR, AJAX, JSON.)

Comments submitted by user are first validated by the web site hosting articles. DWR technology (AJAX for Java) is used to convert user comments HTML form data into Java object and possible validation errors - back into JavaScript callbacks for errors.

Comments that look Ok are submitted to Pluck server hosting all comments to all articles. AJAX technology is also used in this case both to submit the new comment as well as to get back the list of all recent comments (including the new one). JSON is used to get comments back.

Sequence diagram example - submit comments to Pluck using DWR, AJAX, JSON.

Submit comments to Pluck using DWR, AJAX, JSON - UML sequence diagram example.

This diagram also shows some duration constraints. (Disclaimer: constraints shown are fictitious and not describing any real communication.) For example, according to the diagram callback waiting time for posted comment varies from 1 to 4 seconds. At the same time, requesting all posted comments takes only up to 100 msec.