DOM:DOM:Towards a Formal Towards a Formal

SpecificationSpecification

Author: Mark Wheelhouse

Supervisor: Dr. Philippa Gardner

Thanks to: Gareth Smith, Uri Zarfaty, Ian Hodkinson

DOMDOM(Document Object Model)(Document Object Model)

Current Spec.Current Spec. EnglishEnglish

VerboseVerbose AmbiguousAmbiguous

Automated VerificationAutomated Verification Not PossibleNot Possible

ExtensionsExtensions HardHard Time-consumingTime-consuming

What We WantWhat We Want FormalismFormalism

Data StructureData Structure Logical FrameworkLogical Framework

Automated VerificationAutomated Verification PossiblePossible

ExtensionsExtensions EasierEasier QuickerQuicker

What is DOM?What is DOM?DOM Tree

High Level XML UpdateHigh Level XML Update

W3CW3C

Aimed at Object Aimed at Object

Orientated ProgrammersOrientated Programmers

Stores XML in Tree StructureStores XML in Tree Structure

Minimal DOMMinimal DOM

DOM Core Level 3

DOM Core Level 2

DOM Core Level 1

Application Based

Consider Structural Behaviour Only

Minimal DOMMinimal DOM

createNodecreateNode

getNodeNamegetNodeName

getChildNodesgetChildNodes

appendappend

getLengthgetLength

getItemgetItem

getParentNodegetParentNode

insertBeforeinsertBefore

removeChildremoveChild

Minimal DOMMinimal DOM

createNodecreateNode

getNodeNamegetNodeName

getChildNodesgetChildNodes

appendappend

getLengthgetLength

getItemgetItem

getParentNodegetParentNode

insertBeforeinsertBefore

removeChildremoveChild

Context LogicContext Logic

Local Reasoning Tool for Tree UpdateLocal Reasoning Tool for Tree Update

Proved CorrectProved Correct

Used on Toy ExamplesUsed on Toy Examples

Provides Compositional ReasoningProvides Compositional Reasoning

First Real-World TestFirst Real-World Test

Context Logic - ApplicationContext Logic - Application

Pre: P Command: C Post: Q

Context Logic – Right Context Logic – Right TriangleTriangle

K = (P Q)

Data StructureData Structure

Command AxiomsCommand Axioms

{ Pre-condition }

{ Post-condition }

Command

Specifying the Local Behaviour of the commands:

getNodeNamegetNodeName

tag’ = getNodeName(id);

tag’ = tag

getNodeName - Small getNodeName - Small AxiomAxiom

Weakest Pre-conditionWeakest Pre-condition

Weakest Pre-conditionWeakest Pre-condition

Weakest Pre-conditionWeakest Pre-condition

Weakest Pre-conditionWeakest Pre-condition

insertBeforeinsertBefore

insertBefore(parent, newChild, ref);

Ancestor IssueAncestor Issue

insertBefore - AxiominsertBefore - Axiom

Why not Small ?

Weakest Pre-conditionWeakest Pre-condition

Weakest Pre-conditionWeakest Pre-condition

Axiom CompositionAxiom Composition- insertAfter- insertAfter

insertBefore(parent, newChild, ref);

insertBefore(parent, ref, newChild);

Axiom CompositionAxiom Composition- insertAfter- insertAfter

More than Minimal DOMMore than Minimal DOM

cloneNodecloneNode

replaceChildreplaceChild

hasChildNodeshasChildNodes

insertAfter

nodeEquality

DOM Core Level 1:

ConclusionConclusion

Complete Spec. for Minimal DOMComplete Spec. for Minimal DOM

Complete Spec. for Structural DOM Core Complete Spec. for Structural DOM Core Level 1Level 1

Highly ExtendableHighly Extendable

Automated Verification now possibleAutomated Verification now possible

Future WorkFuture Work Automated Verification ToolAutomated Verification Tool

Getting it SmallGetting it Small

The Rest of Core Level 1The Rest of Core Level 1

Higher Levels of DOMHigher Levels of DOM

Concurrent DOMConcurrent DOM