distributed layout management

Distributed Layout Management

Mark R. Boyd

Principal EngineerInformation and Communication Systems

The Church of Jesus Christ of Latter-Day Saints

Formerly Software Architect

Sungard Higher Education

Agenda

• History• Configuring Fragments • Restrictions and Merging • Processor Pipeline • Fragment Manager• Subscribed Fragments• Future work• Questions

What is DLM?

?Distributed Layout Management

?

What is DLM?

Fragment

Fragment

User Owned

What is DLM?

FragmentOwned Tab

Fragment OwnedChannel

User OwnedChannel

What is DLM?

– Fall 2001 Campus Pipeline Platform inflexible UI– uPortal selected for end user customization– But…– Schools must be able to lock some portion of UI – No consensus on what should be locked in place – Only three months to implement– Only one resource available

What is DLM?

CompletelyLocked UI

CompletelyFlexible UI

Schools Choose

What is DLM?

– Leverage uPortal ability to create/edit layouts. (ie: use accounts (fragment owners) as source of fragment.

– Enhance editing with layout element restrictions for fragment owners. (ie: selectively restrict tabs, columns, or channels individually.)

– Facilitate persistence of end user edits to fragment elements.

– Define concept of fragment precedence in view of fragment restrictions.

– Gracefully merge fragment layouts and user edits into a coherent view.

• Result: Distributed Layout Management– Ownership of the portal layout viewed by a user is distributed among

fragment owner accounts and the user’s own edits.

DLM History

2001

2002

uPortal adopted by Campus Pipeline, DLM work starts

DLM 1.0 pushed fragments debut in Luminis

2003

2004

2005

2006

ALM work begins in earnest

SCT asked to contribute DLM

DLM 1.0 debuts in uPortal 2.5

DLM 2.0 Processing Pipeline

2007DLM 2.0 in Luminis

DLM History

• DLM 1.0 (uPortal 2.5)

– Pushed fragments– Variable Restrictions– User Modifications to fragment– XML file based configuration

• DLM 2.0– Graceful Fragment Degratation– Processor pipeline (uPortal 2.6)– Subscribed fragments – Fragment Manager channel/DB based configuration

Configuring Fragments

• <development base dir>/properties/dlm.xml• <web-app base>/WEB-INF/classes/properties/dlm.xml

– Properties.– Fragment account declarations.– Audiences that receive those fragments automatically.

DLM.XML Properties

• <dlm:property name='defaultLayoutOwner' value='fragmentTemplate'/>

– Identifies account whose layout should be copied for any newly created fragment accounts.

DLM.XML Properties

• <dlm:property name='layoutDecorator' value='someClass'/>– Deprecated.– Identifies implementation of interface

org.jasig.portal.layout.dlm.LayoutDecorator.• public void decorate (Document layout,

IPerson person, UserProfile profile)

– Allowed customizations to post-merging layout.

DLM.XML Properties

• <dlm:property name='org.jasig.portal.layout.dlm.RDBMDistributedLayoutStore.fragment_cache_refresh' value="5"/>– Determines refresh period of cached fragment layouts

for layout change propagation to other servers.– Value in minutes.

DLM.XML Fragments

• <dlm:fragment name='Entertainment' ownerID='ent-lo' precedence='100'>

– name = name of fragment, shows when owner is logged in.

– ownerID = username for account whose layout is the fragment’s layout.

– precedence = determine’s ordering and bumping rights. If same as another fragment then index of declaration in dlm.xml is used.

– Content is zero to many <dlm:audience> tags.

DLM.XML Audiences

• <dlm:audience evaluatorFactory=‘<someClass'> – Audience identifies who should get the fragment

layout.– Factory must implement

org.jasig.portal.layout.dlm.EvaluatorFactory.• public Evaluator getEvaluator( Node audience );

– Audience parameter is DOM representation of audience tag’s XML content.

– Content must be well-formed XML understood by declared factory.

DLM.XML Audiences

• <dlm:fragment name='Entertainment' ownerID='ent-lo' precedence='100'>

<dlm:audience evaluatorFactory= 'org.jasig.portal.layout.dlm.providers. PersonEvaluatorFactory'>

<paren mode="NOT"> <attribute name="username" mode='equals' value='guest'/> </paren>

</dlm:audience>

</dlm:fragment>

Determines

Demo

– All users but guest should see Entertainment fragment.

– Entertainment fragment owned by ent-lo account.– Changes to layout should appear for other users.

DLM.XML Audience Factories

– Factory implements org.jasig.portal.layout.dlm.EvaluatorFactory.

• public Evaluator getEvaluator( Node audience );

– Evaluator interface• public boolean isApplicable( IPerson person );

– If any audience evaluator answers true then the fragment is granted.

– Four factories included in org.jasig.portal.layout.dlm.provider package.


– AllUsersEvaluatorFactory• No content. • Always returns true.

– GuestUserEvaluatorFactory• No content.• Returns true if IPerson.isGuest() returns true.


– PersonEvaluatorFactory• Evaluates IPerson.getAttribute(name) values.• Audience can have one to many paren or attribute elements

and “ORs” their responses together.• Paren element has single attribute “mode” with allowed

values of “AND”, “OR”, and “NOT” and nested element outcomes combine accordingly with NOT acting as if it contained a nested, envelopting “OR” paren.

• Attribute element has three attributes:– name: used as the key for IPerson.getAttribute(key).– mode: can be “contains”, “startsWith”, “exists”, “equals”,

and “endsWith”.– value: is the value used for comparison


– PersonEvaluatorFactory quiz• <dlm:audience evaluatorFactory=…>

<attribute name=“eyes” mode=“equals” value=“green”/> <attribute name=“eyes” mode=“equals” value=“hazel”/> <attribute name=“eyes” mode=“equals” value=“brown”/></dlm:audience>

• Will grant the fragment to anyone with green or hazel or brown eyes.



<paren mode=“NOT”> <attribute name=“eyes” mode=“equals” value=“green”/> <attribute name=“hair” mode=“equals” value=“blonde”/> </paren></dlm:audience>

• Will grant the fragment to anyone without both green eyes AND blonde hair. If they have one or the other or both they don’t get it.

• Expression: NOT( eyes=green OR hair=blonde)• Expression: (eyes NOT green) AND (hair NOT blonde)



<paren mode=“NOT”> <attribute name=“eyes” mode=“equals” value=“brown”/> </paren> <attribute name=“eyes” mode=“equals” value=“brown”/></dlm:audience>

• Will grant the fragment to anyone with eyes NOT(brown) OR brown so everyone gets it.


– GroupMembershipEvaluatorFactory• Inherits same logical expressions as in

PersonEvaluatorFactory

• “attribute” element only supports attributes:– mode: “memberOf” and “deepMemberOf”– name: name of the group being checked for membership


– GroupMembershipEvaluatorFactory quiz

• <attribute mode=“memberOf” name=“Everyone”/>– true for Sam, false for Jill.

• <attribute mode=“deepMemberOf” name=“Everyone”/>– true for both Sam and Jill.

Everyone

Students

contains

Sam

Jill


– Extra Credit quiz• <dlm:fragment …>

<dlm:audience evaluatorFactory=“PersonEvaluatorFactory”> <attribute name=“eyes” mode=“equals” value=“brown”/> </dlm:audience> <dlm:audience evalutorFactory=“GroupMembershipEvaluatorFactory”> <attribute mode=“memberOf” name=“Students”/> </dlm:audience></dlm:fragment>

– Multiple audience tags OR’ed together.– Eyes equal brown OR member of Students.

Custom Evaluator Factories

• If you need it, build it.

– Factory implements org.jasig.portal.layout.dlm.EvaluatorFactory.

• public Evaluator getEvaluator( Node audience );

– Evaluator interface• public boolean isApplicable( IPerson person );

DLM.XML Fragment Precedence

• Location, Location, Location – screen real-estate is not created equal.

– DLM’s merging algorithm pushes tabs from granted fragments into user’s layout view.

– Tabs to left bump tabs to the right off of the screen.

– Channels at top bump channels at the bottom off of the screen.

– Identical precedence reverts to index in dlm.xml.

DLM.XML Fragment Precedence

• <dlm:fragment name=‘A‘… precedence='100'>• <dlm:fragment name=‘B‘… precedence=‘50'>• <dlm:fragment name=‘C‘… precedence=‘75'>• <dlm:fragment name=‘D‘… precedence=‘50'>• User tab “E” • and no restrictions (to be discussed shortly)

Quiz: In what order would merged tabs appear?

A C B D E

uPortal Layouts

• Raw uPortal layouts represented by hierarchical folders.

• Structure XSLT transform converts to XML structure indicative of visual presentation.

• Theme XSLT transform converts to target markup like HTML, WML, etc.

uPortal Layouts: pre-DLM

UP_LAYOUT_STRUCTUP_LAYOUT_PARAM

LayoutStore Loads

StructureXSLT

LayoutManager manages

ThemeXSLT

uPortal Layouts: DLM Style


DLM LayoutStore

Loads

DLMStructure

XSLT

DLMLayoutManager

managesDLM

ThemeXSLT ILF

PLF

FragmentCache

Merge

ILF = Incorporated Layout Fragment (user’s viewed layout)

PLF = PersonalLayoutFragment (user’s persisted layout)

uPortal Layouts: Fragment Owners


DLM LayoutStore

Loads

DLMStructure

XSLT

DLMLayoutManager

managesDLM

ThemeXSLT ILF

PLF

FragmentCache

ILF = Incorporated Layout Fragment (user’s viewed layout)

PLF = PersonalLayoutFragment (user’s persisted layout)

same


• Each element originating from a fragment has two added DLM attributes:

– dlm:fragment: the fragment identifier (currently is index in dlm.xml)

– dlm:precedence: the declared precedence of the fragment


• Fragment elements can have restrictions that limit what end users can do. (Asserted false. Not included for true.)– dlm:moveAllowed = restricts lower precedence

elements from moving to a better real-estate location.– dlm:editAllowed = restricts editing structure specific

attributes. (Ex: name for tabs, width for columns)– dlm:deleteAllowed = prevents user from deleting.– dlm:addChildAllowed = restricts adding child

elements. (Ex: columns to tabs and channels to columns.)

• Restrictions set by Fragment owners in uPortal UI.– Demo:renaming and moving

uPortal Layouts: ILF and PLF

• End-user-changes to fragments persisted in user’s layout as “ghost” elements and DLM directives.

• Therefore, each user has two layouts:

• Merging algorithm reapplies changes at log in time as much as is still allowed.

• Garbage collects changes that are not allowed or have no effect. (Self minimizing)

DLM Directives

• dlm:delete = indicates fragment elements that were removed.

• dlm:edit/dlm:pref = an edit made to a fragment element’s attribute.

• dlm:position = indicates user placement of fragment and user owned elements.

• dlm:parm = indicates user added/overridden channel parameter.

Channel Ad-hoc Parameter Persistence

• ChannelStaticData publish time parameters– getParameter(key)– setParameter(key, value)– store()

• Store() depends on support of backing layout management approach. DLM persists ad-hoc parameter changes in PLF via dlm:param directives.

• Fragment Owner values flow to fragment users.– Demo: Post-it channel.

Merging Characteristics Quiz

• What happens if user deleted and element and fragment owner later marked it as not removeable?– The element will reappear and not be removeable

thereafter.• What happens if user adds a channel to a fragment

column and fragment owner later restricts adding channels to that column?– The added channel will be removed.

• What happens if user has rearranged channels in fragment column and fragment owner then adds another channel at the top?– Added channel drops to bottom of column.

DLM and Permissions

• Fragments granted to users via dlm.xml declared evaluators.

• Channels granted to users via group membership.

• Graceful degradation: merging algorithm silently drops channels from fragments if user has insufficient permissions.

FragmentAudience

ChannelAudience

DLM and Permissions (Demo)

<dlm:fragment name='Post-its' ownerID='post-lo' precedence='80'>

<dlm:audience evaluatorFactory=‘…GroupMembership…'>

<paren mode="OR">

<attribute mode='memberOf' name='Students'/>

<attribute mode='memberOf' name='Faculty'/>

</paren>

</dlm:audience>

</dlm:fragment>

DLM and Permissions (Demo)

• post-lo user member of Student and Faculty groups.• “Student Post-its” channel granted to Students.• “Faculty Post-its” channel granted to Faculty.• Post-lo logs in and subscribed to both channels on

“Post-its” tab.• Faculty users see?

– Post-its tab with only Faculty Post-its channel.• Student users see?

– Post-its tab with only Student Post-its channel.

DLM 2.0

• DLM 1.0 opportunities for improvement– File based declaration,

• Administrator access required for host• Propagation tactics in server farm

– Web server bounce required.– No delegation of management responsibilities– No UI processing extensions without recompile– No subscribe-able fragments– No simple enable/disable of fragments

DLM 2.0

UP_DLM_FRAGMENTSUP_DLM_SUBSCRIPTIONS

Pluggable URL Handling Processor Pipeline

FragmentManagerChannel

SubscriberChannel

SubscriptionTargets

Processor

StructureTransformation

ThemeTransformation

IPermissibleImplementation

Delegation

Create FragmentManage PrecedenceManage AudienceManage PermissionsDelete Fragment

RDB Based Configuration

Processing Pipeline

• UI Enhancements• Scenario: Fragment Subscription

Processing Pipeline

• Scenario: Fragment Subscription

Processing Pipeline

• Scenario: Fragment Subscription– Momentarily Injected Structure Specific

Target Points– Modified Structure/Theme Transforms to

Present UI Targets– Provided handling for selected target.

• How do you do that?

Pluggable URL Handling Processor Pipeline

Processing Pipeline

UserInstance

DistributedLayoutManager

processLayoutParameters()

getUserLayout()

SAX Event Stream

Pro

cess

ing

Pip

elin

e

IParameterProcessorIOptionalParameterProcessor

ISaxProcessor

org.jasig.portal.layout.dlm.processing

Processing Pipeline

• Processor Interfaces– IParameterProcessor: URL handler endpoint

• setResources(IPerson, DistributedLayoutManager)• processParameters(UserPreferences, HttpServletRequest)

– IOptionalParameterprocessor: uP_dlmPrc=<processor key>

• isFinished()

– ISaxProcessor: Temporary modifications to layout

• getCacheKey()• getContentHandler(ContentHandler)

Processing Pipeline

• Parameter Processors

processParameters( )

DistributedLayoutManagerProcessLayout

Parameters()

Pro

cess

ing

Pip

e

UserInstance

processParameters() method called on all

processors

getContentHandler( )

User InstanceContent Handler

SAX Event Stream

Processing Pipeline

• SAX Processors


DistributedLayoutManager

getUserLayout()

Pro

cess

ing

Pip

e

UserInstance

SomeContent Handler

returns

ProcessingPipe

Processing Pipeline

• SAX Processors

ISaxProcessorA

ISaxProcessorB

Processing Pipeline

• SAX Processors

ISaxProcessorA

getContentHandler( ) Content Handler A

UICH

Content Handler A

UICH

returns


Processing Pipeline

• SAX Processors

ISaxProcessorB

getContentHandler( ) Content Handler B

CHA

Content Handler B

CHA

returns

Content Handler A

UICH

Processing Pipeline

• SAX Processor Chain


DistributedLayout

Manager

Content Handler

A

Content Handler

B

SAX Event Stream

Processing Pipeline

• Configured in properties/dlmContext.xml– <?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">

<beans> <bean id='dlmProcessingPipe‘ class="org.jasig.portal.layout.dlm.processing.ProcessingPipe singleton="false"> <property name="fixedProcessors">…</property> <property name=“optionalProcessors">…</property> </bean>

– </beans>

Processing Pipeline

– <property name="fixedProcessors"> <list> <bean class=“fully qualified class name" singleton="false"/> <bean class=“another class name" singleton="false"/>

…additional fixed processors

</list></property>

• Singleton: set to true if single instance of the processor can concurrently be used for all users. Ie: thread safe.

Processing Pipeline

– <property name=“optionalProcessors"> <map> <entry key=“some key”> <bean class=“fully qualified class name" singleton="false"/> </entry> <entry key=“another key”> <bean class=“another class name" singleton="false"/> </entry>

…additional entries

</map></property>

• Singleton: be careful.

Fragment Manager Channel

• In Luminis IV, source in sandbox, not yet in uPortal 2.x.


Will always appear until owner logs in for first time.

Owner username.


Sungard proprietary permission aggregation channel.

Fragment Layout Set-up

Fragment Owner logs in


Fragment Owner required to change password


Fragment Owner’sempty layout

Note fragmentname in title.


Fragment Owner’sfinished layout

Enabling a Fragment

AdminEnables Fragment

Note missingpasswordmessage.

Enabling a Fragment

Subscribing to a Fragment

Faculty User

The Road Ahead

• Non-compiling Luminis version of uPortal available in sandbox including I18N feature set.

• I18N features to be rolled into 2.x baseline.– Who?– When?

• DLM 2.0 Changes to be rolled into 2.x baseline. – Who?– When?

Questions

?

distributed layout management

Documents

entertainment fragment

source of fragment

created fragment

fragments layout

view of fragment restrictions

accounts fragment owners

fragment owner accounts

concept of fragment