CPSC 421 Object-Oriented Programming Spring 2025

News

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• Week 13 Class 24 Thu Apr 17 Posted: Apr 17

  Announcements

  • Project 3 Scores in Brightspace. Total points are 110. Maximum score of 100.
  • Exercises We are all caught up on grading exercises. If you have an issue with any of them, please email me the exercise number, title, and issue.

  • Project 4

    For all projects, you need to follow all the coding and design practices. This means that for added classes, you must have a header comment, include guards, the works.

  • Exercise 79: C++ Inheritance Specifiers Crossword

    This is what I tried to do in class on Tuesday, but the network issues prevented it.

    Do this as extra credit. I will drop another lowest-score exercise.

  Agenda

  • Notes: C++ Constructor Specifiers
  • Exercise 81: C++ Constructor Specifiers Crossword

  • Notes: Design Pattern Composite

    Compose objects into tree structures to represent part-whole hierarchies

    Composite lets clients treat individual objects and compositions of objects uniformly

  • Exercise 82: Design Pattern Composite Crossword

  • Notes: Design Pattern Adapter

    Convert the interface of a class into another interface clients expect

    Adapter lets classes work together with incompatible interfaces

  • Exercise 83: Design Pattern Adapter Crossword
  • Notes: Dependency Injection
  • Exercise 84: Dependency Injection Crossword
  • Notes: PIMPL

  Unless otherwise noted, exercises are due by 4:30 pm on Monday, Apr 21

• Project 4 Posted: Apr 08

  Project 4 continues the work on srcFacts. It is due at 11:59:59 pm Tuesday, Apr 22, and involves the following stages which must be performed in order:

  Tag v4a Correct the issues in XMLParser that affect srcfacts, xmlstats, identity, class diagram, and sequence diagram.

  Tag template Redesign XMLParser to use the Template Design Pattern. In this design pattern, extension points are virtual methods. This means new classes that inherit from XMLParser:

  • srcFactsParser in the new files srcFactsParser.hpp and srcFactsParser.cpp
  • IdentityParser in the new files IdentityParser.hpp and IdentityParser.cpp
  • XMLStatsParser in the new files XMLStatsParser.hpp and XMLStatsParser.cpp

  The pull request template adds these new files to your repository and updates the CMakeLists.txt so that they are part of the build. Update your class and sequence diagrams to show this new design.

  As before, our XML parser needs to provide access to all parts of XMLvia the following extension points from [XML notes slide 33]

  XML Extension Point	Attributes
  Start Document
  XML Declaration	version, encoding, standalone
  Element Start Tag	qName, prefix, localName
  Element End Tag	qName, prefix, localName
  Characters	characters
  Attribute	qName, prefix, localName, value
  XML Namespace	prefix, uri
  XML Comment	value
  CDATA	characters
  Processing Instruction	target, data
  End Document

  Tag handler Extract a handler from XMLParser called XMLParserHandler, a new class that only handles the user-defined processing (what we previously had as callbacks). Put the entire XMLParserHandler class in the file XMLParserHandler.hpp.

  Then change srcFactsParser, IdentityParser, and XMLStatsParser to inherit from XMLParserHandler instead of XMLParser, and rename them by replacing "Parser" in the name with "Handler". You can rename the srcFacts files using git:

  Note you will have to commit and push these changes.

  You will also have to rename these files in your CMakeLists.txt. Update your class and sequence diagrams to show this new design.

  Also make sure to update the class names and header comments.

  Warning Once you tag template and move on to handler, you will not be able to change anything for template. So carefully check that you are done with the template part before you tag it and move on to handler

  One prevalent issue in these conversions is that changing XMLParser and srcfacts will cause identity and xmlstats to break until they are converted. To avoid this, understand that make uses the default target all and means make all. So instead of building all executable targets, build them separately as needed, e.g., make srcfacts, make xmlstats, or make identity.

  Keep in mind:

  • You are required to implement these steps in the order given, i.e., tag v4a, tag template, and then tag handler
  • At every commit, ensure the project compiles, builds, and produces the correct answer. Note that it may be only one of the executable targets that builds during conversion.
  • The Template Design Pattern has absolutely nothing to do with the C++ language feature templates. Any use of C++ templates will result in a 0.

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