The Umple Model-Oriented Programming Technology: Easy-to-Use Open-Source Code Generation Code Generation 2013, Cambridge UK Timothy C. Lethbridge, University of Ottawa

My background Once worked at Northern Telecom Collaborated with originators of ObjecTime / IBM Rational Tools since early 1990’s Professor of software engineering at University of Ottawa Have taught software engineering since 1991 Research focuses —Usability of software engineering tools —Empirical studies Recent research support: IBM, Ericsson, General Motors, Defense Deptartment T. Lethbridge Code Generation Umple2

Motivation From our studies of practitioners Code generation is weak in widely-deployed tools Tools are awkward, do not interoperate Modellers mostly —do it for documentation —make important errors From our teaching of modeling Students learned syntax, but failed to learn —Semantics —Pragmatics —To create implementable models due to lack of feedback T. Lethbridge Code Generation Umple3

Umple: Simple, Ample, UML Programming Language 1. Open source code generator for UML The only one that has —Infinitely nested state machines, with concurrency —Proper referential integrity and multiplicity constraints on associations 2. Textual modelling tool set Command line compiler Web-based tool (UmpleOnline) for demos and education Eclipse plugin 3. Pre-processor to add UML, patterns and other features on top of Java, PhP and other languages T. Lethbridge Code Generation Umple4

Exercise: Compiling and Changing a Model Go to Look at the example at the bottom Observe: attribute, association, class hierarchy, mixin Click on Load the above code into UmpleOnline Observe and modify the diagram Add an attribute Make a multiplicity error, then undo Generate code and take a look Download, compile and run if you want T. Lethbridge Code Generation Umple5

Demo of the command line Umple compiler Follows conventions of gcc Used by ant scripts for building T. Lethbridge Code Generation Umple6

Umple Philosophy 1-4 P1. Modeling is programming and vice versa P2. An Umple programmer should never need to edit generated code to accomplish any task. P3. The Umple compiler can accept and generate code that uses nothing but UML abstractions. -The above is the inverse of the following P4. A program without Umple features can be compiled by an Umple compiler. e.g. input Java results in the same as output T. Lethbridge Code Generation Umple7

Umple Philosophy 5-8 P5. A programmer can incrementally add Umple features to an existing program Umplification P6. Umple extends the base language in a minimally invasive and safe way. P7. Umple features can be created and viewed diagrammatically or textually P8. Umple goes beyond UML T. Lethbridge Code Generation Umple8

A look at selected Umple features Attributes Associations Notice the inline and independent state machines State Machines Switch to ‘GraphViz state diagram’ in the options menu T. Lethbridge Code Generation Umple9

Umple Architecture 1 Grammar DSL: Online (we migrated from Antlr to better handle embedded code blocks and gain flexibility) Umple is written in itself Key to testing and reliability ise.umple/src/Umple.umphttp://code.google.com/p/umple/source/browse/trunk/cru ise.umple/src/Umple.ump T. Lethbridge Code Generation Umple10

Umple Architecture 2 Umple’s own class diagram generated by itself from itself: Colours represent key subsystems Click on classes to see Javadoc, and then Umple Code T. Lethbridge Code Generation Umple11

Testing: TDD with100% pass always required Multiple levels: Parsing tests: basic constructs Metamodel tests: ensure it is populated properly —E.g. cruise/umple/compiler/AssociationTest.java cruise/umple/compiler/AssociationTest.java Implementation template tests: to ensure constructs generate code that looks as expected Testbed semantic tests: Generate code and make sure it behaves the way it should T. Lethbridge Code Generation Umple12

Continuous integration Small increments compiled frequently Single trunk, no branches for now Online QA report: T. Lethbridge Code Generation Umple13

Code Generation Approach 1 Generation relies on ‘walking’ the metamodel Where possible, new features are added by layering on top of the existing ones e.g. —There was an existing ‘code injection’ feature —Constraints were implemented almost entirely at the metamodel level by adding ‘before’ and ‘after’ code injections T. Lethbridge Code Generation Umple14

Code Generation Approach 2 Each generator is a separate plugin and can have a different architecture Use Jet templates Language independent common templates — %2Ftrunk%2FUmpleToTemplate%2Ftemplateshttp://code.google.com/p/umple/source/browse/#svn %2Ftrunk%2FUmpleToTemplate%2Ftemplates Language-specific templates — %2Ftrunk%2FUmpleToJava%2Ftemplateshttp://code.google.com/p/umple/source/browse/#svn %2Ftrunk%2FUmpleToJava%2Ftemplates Language-specific translation functions — /cruise.umple/src/Generator_CodeJava.umphttp://code.google.com/p/umple/source/browse/trunk /cruise.umple/src/Generator_CodeJava.ump T. Lethbridge Code Generation Umple15

Code generation lessons from Umple 1 Process of developing Umple Agile continuous integration Language written in itself Multi-level test-driven development Process for all users of Umple Modeling and programming at the same level Many semantic model checks produce warnings & errors Round trip engineering is banished Generation of diagrams from text and text from diagrams IDE Flexibility: Eclipse / Web / Command line Incremental umplification T. Lethbridge Code Generation Umple16

Code generation lessons from Umple 2 Language features Deep attention to detail in state machines and UML associations Mixins for separation of concerns Multi-lingual generation and embedding Generated code looks nice —No ‘Umple runtime’ —Can be inspected to gain confidence —No risk adoption T. Lethbridge Code Generation Umple17

Evidence of benefit Umple in use an a couple of small companies Umple development in itself 20+ developers Empirical studies show Umple code is easier to understand than Java Helps students learn to model: CSEE&T T. Lethbridge Code Generation Umple18

Results of survey T. Lethbridge CSEE&T Umple in the classroom helped me understand concepts Umple in the lab helped me understand concepts I will get better grades because of Umple Prof. Lethbridge should use it in future courses As of Dec 2010, Umple is too incomplete or buggy Other tools would have been just as effective I would use Umple in the future, assuming bugs fixed

T. Lethbridge CSEE&T Availability of a textual form for models and diagrams Ability to edit diagram or text & have the other reflect changes Ability to generate code to represent the model

Comparison of Grades Comparison of 4 offerings of the same course before introducing Umple, and 2 offerings afterwards Midterm examination grades on UML modeling question rose from 75.8% to 82.3% 8.6% improvement Final exam grades on UML modeling questions rose from 76.4% to 83.6% 9.4% improvement Highly statistically significant p< on T Test n=332 prior to Umple; n=137 afterwards Similar results in 4 th year course SEG4110 No difference in non-UML questions T. Lethbridge CSEE&T

The Near Future Real time UML/Autosar extensions Robust C/C++ generation Application for Eclipse Foundation hosting Seek industrial uptake T. Lethbridge Code Generation Umple22

A Few Direct Web Links UmpleOnline User Manual Google Code Hosting Site This presentation: orial-CodeGeneration.ppt T. Lethbridge Code Generation Umple23

Questions? T. Lethbridge Code Generation Umple24