UML reference manual
Part II Based Overview
Chapter 7 Active Views 7.1 Overview Activity Diagram is a special form of state machine for modeling computing processes and workflows. The status in the activity diagram indicates the various states in the calculation process, rather than the state of the normal object. Typically, the activity chart assumes that there is no interrupt caused by an external event throughout the calculation process, otherwise, the normal state machine is more suitable for describing this. The active diagram contains the active status. Active status indicates the execution of the command or workflow in the process of the process. Unlike the normal waiting states that occurred in a certain event, the active status waits for the completion of the processing work. When the activity is complete, the execution process is transferred to the next active state in the active diagram. When the active leading activity is completed, the completion conversion in the activity graph is excited. The active state usually does not explicitly indicates an event that causes activity conversion. When the closing cycle is converted, the active state will be extremely terminated. The active map can also include action status, which is similar to the active state, but they are atomic activities and are not allowed when they are active. The operating state is usually used for short billing operations. The active diagram can include bifurcation control of concurrent threads. The concurrent thread represents activities that can be implemented by different objects and people in the system. Usually, it is generated from gathering, and each object has their own thread in the aggregation relationship, which can be implemented concurrently. Concurrent activities can be executed simultaneously. The activity map not only can express sequential flow control, but also can express concurrent flow control. If this is excluded, the activity map is like a traditional flow chart. 7.2 Activity Chart Activity Diagram is a representation of an active view (as shown in Figure 7-1). It includes some convenient quick notes symbols that can actually be used for any state diagram, although the mix of activity maps and status maps are ugly. The active state represents a rectangle with a circular side line, which contains a description of the activity (the ordinary state cartridge is a straight roll). Simple complete conversion arrows are indicated. The branch represents the monitoring condition of the conversion or a diamond shape having a multi-marked outlet arrow. The controlled bifurcation and binding are the same as the representation in the state diagram, and is a plurality of arrows entering or leaving the dark sync strip. Figure 7-1 shows an active diagram of an order processing. 7-1 Active diagram In order to indicate an external event must be included in the scenario, the reception of the event can be represented as a conversion trigger or a special embedded symbol waiting for a signal. Send can also be represented. However, if there are many event-driven conversions, it is more desirable to use a normal state diagram. 1. Swimming lanes are usually useful in organizing activities in the model. For example, all activities processed by a commercial organization can organize all activities. This allocation can be represented by different regions separating the active tissue. These areas are referred to as a lane due to their appearance. Figure 7-2 shows a lane. Figure 7-2 Lanes and object flow 2. Object flow activity maps can represent the value of the object and the control flow. Object flow status indicates an object input or output in the activity. For the output value, the dotted arrow is directed from the active point to the target. For input values, the dotted arrow points from the object flow state to the activity. If there is a plurality of output values or subsequent control flows, the arrow is back to the bifid. Similarly, the multi-input arrow points to the combination symbol. Figure 7-2 shows an active diagram of an activity and object flow state being assigned to a lane. 7.3 Activities and other diagrams do not indicate all of the details of the calculation process. They represent the flow of activities but did not indicate the object of executing activities. The activity map is the starting point for design work. To complete the design, each activity must be extended into one or more operations, each operation being assigned to the specific class. The result of this assignment leads to the design of the associations for realizing the activity map.
