Declaratively Producing Data Mash-ups

Sudarshan Murthy1, David Maier2

1Applied Research, Wipro Technologies2 Department of Computer Science, Portland State University

http://www.sixml.org

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Mash-ups

• Web applications that combine information from multiple sources [Wikipedia]– A mash-up does not need to be a web app

• Data that includes or transcludes content from multiple sources

• In either case, a source is likely only a fragment

• This work is about data mash-ups– In this talk, a mash-up is an XML document

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Portland State University Campus Map

• 45 markers, 53 landmarks– Marker: Balloon

on map– Landmark:

Building, department, …

• Information from 188 fragments in 58 web pages

• Fragments selected manuallyhttp://sparce.cs.pdx.edu/cmap/

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Portland Metro Food Markets

• 154 markers, 154 landmarks

• 154 fragments harvested programmatically from 4 MS Word documents

• Developed for the Oregon Department of Agriculture

http://sparce.cs.pdx.edu/Declaratively Producing Data Mash-ups/oda-1.1/

An HTML Review Report

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Problem Areas

• Development– Getting data from heterogeneous fragments– Might use a DBMS, yet code operators such

as sort, join, and aggregate for external data

• Execution– When to get external data, how much to get?

• Design: Expressing that– A part comes from an external fragment– A part is data (such as page number) which

cannot be “selected” in the source

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Outline

• Introduction• The conceptual approach• Sixml: Condensed mash-ups• Sixml DOM: Reconstituted mash-ups• Sixml Navigator: Formatted mash-ups• Evaluation• Summary• Discussion

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Superimposed Information (SI)

• SI is new data and structure overlaid on existing base information

• Mark: A reference to an external fragment

• Benefits– Multiple, simultaneous

organizations – Make new connections

among base fragments– Preserve context

Superimposed

Layer

Base Layer

Information Source1

Information Source2

Information Sourcen

…

marks

Heterogeneous sources: Word, Excel, PDF, HTML,…

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The Mash-up Production Process

Collect marks, add new data and structure

Extract data from marks and combine with added data

Collect and Classify Extract and Combine Transform

DocsDBMS

Services

Services

Format reconstituted data for display and other purposes

Services

Condensed mash-up

Reconstitutedmash-up

DBMS DocsDBMS Docs

Formattedmash-up

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SI, Bi-level Information, Mash-ups

• A condensed mash-up is SI– Links mash-up parts to external fragments– Relates to mash-up design: Sixml

• A reconstituted mash-up and a formatted mash-up are both bi-level information – SI plus reconstituted parts– Relates to runtime mash-up manipulation

and execution: Sixml DOM and Sixml Navigator

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Outline

• Introduction• The conceptual approach• Sixml: Condensed mash-ups• Sixml DOM: Reconstituted mash-ups• Sixml Navigator: Formatted mash-ups• Evaluation• Summary• Discussion

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Sixml

• A mash-up specification language – SI represented as XML; Sixml is XML

• A condensed mash-up is encoded as a Sixml document

• A mark association is encoded as an XML element of a type we define– Associate marks with six kinds of content– Validated using standard schema constructs– Uniform and comprehensible serialization

<Comment excerpt="" xmlns:sixml="http://schema.sixml.org"> <sixml:TMark> Contradicts prior work <sixml:Descriptor>…</sixml:Descriptor> </sixml:TMark> <sixml:AMark target="excerpt"> <sixml:Descriptor>…</sixml:Descriptor> </sixml:AMark> <sixml:EMark> <sixml:Descriptor>…</sixml:Descriptor> </sixml:EMark></Comment>

<Comment excerpt="" xmlns:sixml="http://schema.sixml.org"> <sixml:TMark> Contradicts prior work <sixml:Descriptor>…</sixml:Descriptor> </sixml:TMark> <sixml:AMark target="excerpt" sixml:valueSource="true"> <sixml:Descriptor>…</sixml:Descriptor> </sixml:AMark> <sixml:EMark> <sixml:Descriptor>…</sixml:Descriptor> </sixml:EMark></Comment>

<Comment excerpt=""> Contradicts prior work</Comment>

<Comment excerpt="" xmlns:sixml="http://schema.sixml.org"> Contradicts prior work <sixml:EMark> <sixml:Descriptor>…</sixml:Descriptor> </sixml:EMark></Comment>

<Comment excerpt="" xmlns:sixml="http://schema.sixml.org"> Contradicts prior work <sixml:AMark target="excerpt"> <sixml:Descriptor>…</sixml:Descriptor> </sixml:AMark> <sixml:EMark> <sixml:Descriptor>…</sixml:Descriptor> </sixml:EMark></Comment>

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Sixml Mark Associations

• By default text excerpt is assigned at run time, but possible to declare that the value should be something other than the excerpt• Mark association names shown here are same as type name, but custom names are possible (with both static and dynamic typing)

<Comment excerpt="" xmlns:sixml="…" xmlns:xsi="…"> <sixml:TMark> Contradicts prior work <sixml:Descriptor xsi:type="sixml:XPointer">  <pointer>http://www.w3.org/#element(/1/2)</pointer> </sixml:Descriptor> </sixml:TMark> <sixml:AMark target="excerpt" sixml:valueSource="true"> <sixml:Descriptor>…</sixml:Descriptor> </sixml:AMark> <sixml:EMark> <sixml:Descriptor xsi:type="sixml:SPARCE"> <Agent>OfficeAgents.MSWord</Agent> <Doc location="c:\abc.doc" /> <Subdoc startChar="45" endChar="53" /> </sixml:Descriptor> </sixml:EMark></Comment>Apr 21, 2023 Declaratively Producing Data Mash-ups 14

Sixml Mark Descriptors

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Outline

• Introduction• The conceptual approach• Sixml: Condensed mash-ups• Sixml DOM: Reconstituted mash-ups• Sixml Navigator: Formatted mash-ups• Evaluation• Summary• Discussion

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Sixml DOM

• Extends W3C XML DOM to easily manipulate Sixml documents – Using DOM can be tedious and inefficient

• Automatic and lazy reconstitution– Detects mark associations and interprets

attributes such as sixml:valueSource– Developer uses only the DOM interface

• Access to descriptors and “context” of external fragments

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Run-time Representation

A Descriptor

AMark

A Descriptor

EMark

5. @markID@a“text”

“Contradicts…” A

“excerpt”

@excerpt

Comment

TMark

true

A @target

“” @valueSource A Descriptor

<Comment excerpt="" xmlns:sixml="http://schema.sixml.org"> <sixml:TMark> Contradicts prior work <sixml:Descriptor>…</sixml:Descriptor> </sixml:TMark> <sixml:AMark target="excerpt" sixml:valueSource="true"> <sixml:Descriptor>…</sixml:Descriptor> </sixml:AMark> <sixml:EMark> <sixml:Descriptor>…</sixml:Descriptor> </sixml:EMark></Comment>

DOM tree

A Context TMark

EMark

5. @markID@a“text” A Descriptor

A Descriptor

A Descriptor

A @valueSource

“provides…”

“excerpt”

@excerpt

true

A @target

Comment

“Contradicts…”

A Context

A Context

AMark

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Generating a Sixml DOM Tree

A Descriptor

AMark

A Descriptor

EMark

5. @markID@a“text”

“Contradicts…” A

“excerpt”

@excerpt

Comment

TMark

true

A @target

“” @valueSource A Descriptor

Sixml DOM tree

A mark association is “attached” to its target, but is not a child - The DOM interface suffices to access the reconstituted mash-up

Descriptor is not a child

Value reconstituted

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Context Information• Information retrieved from the context of an

external fragment

• An xsi:type-specific implementation determines (statically or dynamically) what is in context

<sixml:Context> <Content> <Text>provide ... system</Text>   </Content> <Presentation> <FontName>Times New Roman</FontName>   <FontSize>11</FontSize> </Presentation> <Placement> <Page>3</Page> </Placement></sixml:Context>

Programming with Sixml DOM

1.procedure WriteComment(SixmlElement c)2. XmlElement ctxt = c.markAssociations[0].Context

3. XmlNode page = ctxt.getElementsByTagName("Page")[0]

4. Writeln("Page: ", page.firstChild.nodeValue)

5. Writeln("Excerpt: ", c.getAttribute("excerpt"))

6. Writeln("Comment: ", c.firstChild.nodeValue)

• Only Lines 1 and 2 use the Sixml DOM interface

• Lines 2–4 get page number; Line 5 the reconstituted excerpt; and Line 6 the comment text

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Outline

• Introduction• The conceptual approach• Sixml: Condensed mash-ups• Sixml DOM: Reconstituted mash-ups• Sixml Navigator: Formatted mash-ups• Evaluation• Summary• Discussion

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Sixml Navigator

• Alternative to the traditional path navigator

• Extends XDM so that Sixml documents can be declaratively queried using existing languages and query processors– Also applies to XPath 1.0 and XSLT 1.0

• Performs automatic and lazy reconstitution

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XDM Extensions

• Allow child elements for any kind of node with which a mark may be associated

• Make a mark association a child of its target node

• Represent a mark descriptor and context as children of a mark association

• These extensions allow reuse of existing query languages and processors

A Context TMark

EMark

5. @markID@a“text” A Descriptor

A Descriptor

A Descriptor

A @valueSource

“provides…”

“excerpt”

@excerpt

true

A @target

Comment

“Contradicts…”

A Context

A Context

AMark

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An Extended-XDM Tree

A Context TMark

EMark

5. @markID@a“text” A Descriptor

A Descriptor

A Descriptor

A @valueSource

@excerpt

A @target

Comment

“Contradicts…”

A Context

A Context

AMark

Extended-XDMtree

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Queries over Bi-level Information

• With Comment as current node, get the comment text

./text()

• Get excerpt of commented region ./@excerpt

• Get page number of commented region ./sixml:EMark/sixml:Context/Placement/Page

<sixml:Context> <Placement> <Page>3</Page> </Placement></sixml:Context>

EMark

5. @markID@a“tA Descriptor A Context

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Outline

• Introduction• The conceptual approach• Sixml: Condensed mash-ups• Sixml DOM: Reconstituted mash-ups• Sixml Navigator: Formatted mash-ups• Evaluation• Summary• Discussion

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Implementation and Usage

• Element types for Sixml mark associations defined in XML Schema

• Sixml DOM and Sixml Navigator in C# on the .NET Framework– Sixml DOM implemented by extending DOM

and by revising DOM– Three implementations of Sixml DOM: 2

extensions (MS and Mono), 1 revision (Mono)

• Sixml, Sixml DOM, and Sixml Navigator used in mash-ups for several applications

Experimental Data

• 8 mash-ups – 4 each from 2 apps; different scale factors– File size: 200 KB to 26.1 MB– #Docs referenced: 18 to 426– #Mark associations: 1.9K to over 311K

• 3 traditional XML documents– File size: 484 KB to 113.7 MB– Tree depth: 4, 8, 16

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Evaluation Summary

• Sixml DOM– Saves time over DOM when accessing mark

associations– When accessing SI, savings decrease as

the amount of SI increases– It is better to use DOM to access large

traditional XML documents

• Sixml Navigator– Saves time over traditional navigator for

both mark associations and SI

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Outline

• Introduction• The conceptual approach• Sixml: Condensed mash-ups• Sixml DOM: Reconstituted mash-ups• Sixml Navigator: Formatted mash-ups• Evaluation• Summary• Discussion

Summary

• A mash-up has three forms: condensed, reconstituted, and formatted

• Sixml, Sixml DOM, and Sixml Navigator support the three forms, respectively

• Sixml makes it easier to specify mash-ups; Sixml DOM and Navigator provide a more efficient means of manipulating mash-ups

• The XML Schema instance documents and the source code are on www.sixml.org

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Outline

• Introduction• The conceptual approach• Sixml: Condensed mash-ups• Sixml DOM: Reconstituted mash-ups• Sixml Navigator: Formatted mash-ups• Evaluation• Summary• Discussion

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Our Mash-up Framework

XSLT and XQuery Processors

XPath ProcessorClient Application

Sixml Sixml DOM Sixml Navigator

SPARCE Bulk Accessor Cloaker

Reference and retrieve fragments of arbitrary types

Efficiently retrieve large number of fragments

Hide data to improve query expression and execution

Bi-level Query Processors

• Sixml Navigator uses Sixml DOM internally: Does not construct extended-XDM trees

• Existing query processors use the Sixml Navigator instead of using the traditional navigator

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BulkAccessor transform(contextInfo) XMLContextTransformer

scope SixmlNavigator

0..1 *

Produces

apply(styleSheet) XSLTProcessor

Node Evaluation Context 1 *

Embeds

Source * *

moveToRoot() moveToFirstChild() moveToNextSibling() moveToPreviousSibling() moveToParent()

XPathNavigator

evaluate(expression) XPathEvaluator

1 * Uses

SixmlNode

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Mark Creation

Superimposed Application

Mark Manager

Clipboard

Superimposed Info Descriptors

Repository

<Mark ID="M4"> <Agent>AcrobatAgents.PDFAgent</Agent> <Class>AcrobatPDFTextMark</Class>  <Address>2|395|439</Address> …   <ContainerID>D6</ContainerID> </Mark>

M4S1

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Activation and Context Retrieval

Superimposed Application

Mark Manager

Context Manager

Superimposed Info

Base Application

Descriptors Repository

Base Info

<Mark ID="M4"> <Agent>AcrobatAgents.PDFAgent</Agent> <Class>AcrobatPDFTextMark</Class>  <Address>2|395|439</Address> …   <ContainerID>D6</ContainerID> </Mark>

M4S1

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About ContextPDF Mark PowerPoint Mark

• Context information is modeled as a hierarchical property set