UML Sequence Diagramming
Describe how to diagram a Reply message in a sequence diagram?
Reply messages are used to show the message being sent from the receiver to the sender We represent a return/reply message using an open arrowhead with a dotted line The interaction moves forward only when a reply message is sent by the receiver
What are the benefits of using sequence diagrams?
1. Represent the details of a UML use case 2. Model the logic of a procedure, function, or operation 3. Show how objects and components interact with each other to complete a process 4. Plan and understand the detailed functionality of an existing or future scenario
What are the two types of UML Diagrams?
1. Structural Diagram 2. Behavioral Diagram
What are the different types of Message arrows in a sequence diagram?
1. Synchronous 2. Asynchronous 3. Create 4. Delete 5. Self 6. Reply 7. Found 8. Lost 9. Guards (Constraint)
Describe how to diagram a Found message in a sequence diagram?
A Found message is used to represent a scenario where the an unknown source sends the message It is represented using an arrow directed towards a lifeline from an end point
What is a Lifeline in a sequence diagram?
A Lifeline is a named element that depicts an individual participant in a sequence diagram. Each instance in a sequence diagram is represented by a Lifeline and Lifeline elements are located at the top of a sequence diagram.
Describe how to diagram a Lost message in a sequence diagram?
A Lost message is used to represent a scenario where the recipient is not known to the system It is represented using an arrow directed towards an end point from a lifeline
What is a UML Sequence Diagram?
A sequence diagram describes how and in what order a group of objects works together. Sequence diagrams show interactions between objects over a specific period of time. More specifically a sequence diagram visualizes a series of calls in a system to perform specific functionality.
Describe how to diagram a Synchronous message in a sequence diagram?
A synchronous message waits for a reply before the interaction can move forward. The sender waits until the receiver has completed the processing of the message The caller continues only when it knows that the receiver has processed the previous message i.e. it receives a reply message A solid arrow head is used to represent a synchronous message
What is an Activation Box in a sequence diagram?
An Activation Box represents the time needed for an object to complete a task. The longer the task will take, the longer the activation box, visually, becomes in a UML diagram
What is an Actor in a sequence diagram?
An Actor in a UML diagram represents a type of role where it interacts with the system and its objects Actors depict various roles including human users and other external subjects A stick person (see image) represents an Actor We can have multiple actors in a sequence diagram
What is an Object Symbol in a sequence diagram?
An Object Symbol represents a class or object in UML. This object symbol demonstrates how an object will behave in the context of the system. We should not list class attributes using this shape.
Describe how to diagram a Asynchronous message in a sequence diagram?
An asynchronous message does not wait for a reply from the receiver The interaction moves forward irrespective of the receiver processing the previous message or not We use a lined arrow head to represent an asynchronous message
What are Message Elements in a sequence diagram?
Communication between objects are depicted using Messages. The Messages appear in a sequential order on the Lifeline and are represented by arrows.
Describe how to diagram a Self message in a sequence diagram?
In certain scenarios the object in a diagram may need to send a message to itself like in recursive methods. Such messages are called Self Messages. Represented with a U-shaped arrow.
What is the UML Behavioral Diagram used for?
It is used to depict the elements of a system that are dependent on time and dynamic concepts of the system and also how those systems relate to each other The different types of UML Behavioral Diagrams are: 1. Activity diagrams 2. Use Case diagrams 3. State Machine diagrams 4. Timing diagrams 5. Sequence diagrams 6. Communication diagrams 7. Interaction Overview diagrams
What is the UML Structural Diagram used for?
It is used to depict the static elements of a system are are independent of time. The different types of UML Structural Diagrams are: 1. Class diagram 2. Object diagram 3. Component diagram 4. Composite structural diagram 5. Deployment diagram 6. Package diagram 7. Profile diagram
Diagram a Remote Call-In pattern using either REST or SOAP API to query a Salesforce object
See attached image
Describe how to diagram a Guard(Constraint) message in a sequence diagram?
To model conditions we use Guards in UML They are used when we need to restrict the flow of messages on the pretext of a condition being met Guards play an important role in letting software developers know the constraints attached to a system or a particular process
What does UML stand for?
Unified Modeling Language It is a standard modeling language for designing and documenting a system in an object oriented manner.
Describe how to diagram a Delete message in a sequence diagram?
We can use a Delete Message to delete an object. When an object is deallocated memory or is destroyed within the system we can use the Delete Message symbol. It destroys the occurrence of the object in the system. It is represented by an arrow terminating with an x.
Describe how to diagram a Create message in a sequence diagram?
We use a Create message to instantiate a new object in the sequence diagram. It is represented with a dotted arrow and the "create" word labelled on it to specify that it is the create Message symbol
