CSC302H1 Lecture 5: 2014.01.21
Document Summary
Sequence diagrams model behavior of code: execution traces shows runtime interactions btwn users and system. Focus on individual scenarios: normally used for lower-level design. Sequeance diagram legend: actor the stick figure. Represents something outside the system b/c the system may interface w/ an external system or a user: time flows top to bottom, objects layed out horizontally, higher ones exists earlier. Lifeline dotted line extending from objects, indicats when the object is alive/exists in the system. Upon object creation new object in sequence. Upon object destruction x placed on the diagram lifeline. Activation bar bar on the life lin. Shows then the object is at the top of the. Bars on top of each other = series of calls waiting callstack to return. Bars usually created by an method call: operations left/right solid arrows. Usually invoks an activation, or creates an object. Sequence diagram usually starts w/ run/execut command.
