atomgraph / web-client

Generic Linked Data browser and UX component framework. Apache license.

AtomGraph Web-Client is a Linked Data web client. If you have a triplestore with RDF data that you want to publish and/or build an end-user application on it, or would like to explore Linked Open Data, Web-Client provides the components you need.

Web-Client renders (X)HTML user interface by transforming "plain" RDF/XML (without nested resource descriptions) using XSLT 3.0 stylesheets.

Features

What AWC provides for users as out-of-the-box generic features:

• loading RDF data from remote Linked Data sources
• multilingual, responsive user interface built with Twitter Bootstrap (currently 2.3.2)
• multiple RDF rendering modes (currently item/list/table/map)
• RDF editing mode based on RDF/POST encoding
• SPARQL endpoint with interactive results

Getting started

• what is Linked Data
• installing Web-Client
• extending Web-Client

For full documentation, see the wiki index.

Usage

Docker

Processor is available from Docker Hub as atomgraph/web-client image. It accepts the following environment variables (that become webapp context parameters):

STYLESHEET

Custom XSLT stylesheet

URI, optional

RESOLVING_UNCACHED

If true, the stylesheet will attempt to resolve (dereference) URI resources in the rendered RDF data to improve the UX

true/false, optional

Run Web-Client with the default XSLT stylesheet like this:

docker run -p 8080:8080 atomgraph/web-client

Web-Client will be available on http://localhost:8080.

Maven

Web-Client is released on Maven central as com.atomgraph:client.

Support

Please report issues if you've encountered a bug or have a feature request.

Commercial AtomGraph consulting, development, and support are available from AtomGraph.

Community

Please join the W3C Declarative Linked Data Apps Community Group to discuss and develop AtomGraph and declarative Linked Data architecture in general.

web-client's Issues

Quick browsing in Input view

Currently the Input view for a container lists all the items in this container, and all the properties that apply to the item and than can be modified.

This results in a very long list, that is not easy to navigate.

Since there is space on the side, a flat list of all the items could be listed on the side. Clicking on an item would scroll to center view to it.

Additionally, for better visibility, the items listed in the center view could be collapsed, until the users clicks on them or select them in this new side list.

http://getbootstrap.com/2.3.2/components.html The side bar could be used for this side list, with a smaller font and line height.

ModelXSLTWriter directly using client-defined language

ModelXSLTWriter is passing Accept-Language value as $lang parameter, which is not always the language of the selected Variant (highest-ranked client language might not be in the Variant list on the server)

Not viewing dbpedia:France resouce

Hi,
First of all this is a cool stuff for visualization. I was playing a bit today, but at some point it was not possible to load this page: http://dbpedia.org/resource/France; althought I can retrieve the .ttl file.
Is it a matter of encoding?

Again, great job!

Best,
Ghislain

Circular definition of $ont-model

Error on line 117 of Resource.xsl:
XTDE0640: Circular definition of variable ont-model
in variable ont-model (file:///usr/local/apache-tomcat-7.0.26/webapps/ROOT/WEB-INF/Resource.xsl#95)
01:09:00,062 ERROR ResourceXHTMLWriter:139 - XSLT transformation failed
; SystemID: file:///usr/local/apache-tomcat-7.0.26/webapps/ROOT/WEB-INF/Resource.xsl; Line#: 117; Column#: -1
net.sf.saxon.trans.XPathException: Circular definition of variable ont-model
at net.sf.saxon.expr.ErrorExpression.evaluateItem(ErrorExpression.java:58)
at net.sf.saxon.expr.ErrorExpression.iterate(ErrorExpression.java:71)
at net.sf.saxon.expr.ExpressionTool.evaluate(ExpressionTool.java:308)
at net.sf.saxon.instruct.GlobalVariable.getSelectValue(GlobalVariable.java:209)
at net.sf.saxon.instruct.GlobalVariable.evaluateVariable(GlobalVariable.java:233)
at net.sf.saxon.expr.VariableReference.evaluateVariable(VariableReference.java:480)
at net.sf.saxon.expr.VariableReference.evaluateItem(VariableReference.java:447)
at net.sf.saxon.functions.KeyFn.iterate(KeyFn.java:203)
at net.sf.saxon.instruct.ForEach.processLeavingTail(ForEach.java:278)
at net.sf.saxon.instruct.Block.processLeavingTail(Block.java:556)
at net.sf.saxon.instruct.Instruction.process(Instruction.java:93)
at net.sf.saxon.instruct.ElementCreator.processLeavingTail(ElementCreator.java:296)
at net.sf.saxon.instruct.Block.processLeavingTail(Block.java:556)
at net.sf.saxon.instruct.Instruction.process(Instruction.java:93)
at net.sf.saxon.instruct.ElementCreator.processLeavingTail(ElementCreator.java:296)
at net.sf.saxon.instruct.Template.applyLeavingTail(Template.java:203)
at net.sf.saxon.instruct.ApplyTemplates.applyTemplates(ApplyTemplates.java:345)
at net.sf.saxon.Controller.transformDocument(Controller.java:1807)
at net.sf.saxon.Controller.transform(Controller.java:1621)
at org.graphity.util.XSLTBuilder.transform(XSLTBuilder.java:191)
at org.graphity.browser.provider.xslt.ResourceXHTMLWriter.writeTo(ResourceXHTMLWriter.java:134)
at org.graphity.browser.provider.xslt.ResourceXHTMLWriter.writeTo(ResourceXHTMLWriter.java:49)
at com.sun.jersey.spi.container.ContainerResponse.write(ContainerResponse.java:306)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1316)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1229)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1219)
at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:419)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:699)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:200)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
Aug 2, 2012 1:09:00 AM com.sun.jersey.spi.container.ContainerResponse logException
SEVERE: Mapped exception to response: 500 (Internal Server Error)
javax.ws.rs.WebApplicationException: net.sf.saxon.trans.XPathException: Circular definition of variable ont-model
at org.graphity.browser.provider.xslt.ResourceXHTMLWriter.writeTo(ResourceXHTMLWriter.java:140)
at org.graphity.browser.provider.xslt.ResourceXHTMLWriter.writeTo(ResourceXHTMLWriter.java:49)
at com.sun.jersey.spi.container.ContainerResponse.write(ContainerResponse.java:306)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1316)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1229)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1219)
at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:419)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:699)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:200)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
Caused by: net.sf.saxon.trans.XPathException: Circular definition of variable ont-model
at net.sf.saxon.expr.ErrorExpression.evaluateItem(ErrorExpression.java:58)
at net.sf.saxon.expr.ErrorExpression.iterate(ErrorExpression.java:71)
at net.sf.saxon.expr.ExpressionTool.evaluate(ExpressionTool.java:308)
at net.sf.saxon.instruct.GlobalVariable.getSelectValue(GlobalVariable.java:209)
at net.sf.saxon.instruct.GlobalVariable.evaluateVariable(GlobalVariable.java:233)
at net.sf.saxon.expr.VariableReference.evaluateVariable(VariableReference.java:480)
at net.sf.saxon.expr.VariableReference.evaluateItem(VariableReference.java:447)
at net.sf.saxon.functions.KeyFn.iterate(KeyFn.java:203)
at net.sf.saxon.instruct.ForEach.processLeavingTail(ForEach.java:278)
at net.sf.saxon.instruct.Block.processLeavingTail(Block.java:556)
at net.sf.saxon.instruct.Instruction.process(Instruction.java:93)
at net.sf.saxon.instruct.ElementCreator.processLeavingTail(ElementCreator.java:296)
at net.sf.saxon.instruct.Block.processLeavingTail(Block.java:556)
at net.sf.saxon.instruct.Instruction.process(Instruction.java:93)
at net.sf.saxon.instruct.ElementCreator.processLeavingTail(ElementCreator.java:296)
at net.sf.saxon.instruct.Template.applyLeavingTail(Template.java:203)
at net.sf.saxon.instruct.ApplyTemplates.applyTemplates(ApplyTemplates.java:345)
at net.sf.saxon.Controller.transformDocument(Controller.java:1807)
at net.sf.saxon.Controller.transform(Controller.java:1621)
at org.graphity.util.XSLTBuilder.transform(XSLTBuilder.java:191)
at org.graphity.browser.provider.xslt.ResourceXHTMLWriter.writeTo(ResourceXHTMLWriter.java:134)
... 25 more

Upgrade to JAX-RS and Jersey to 2.x

http://java.dzone.com/articles/jax-rs-20-and-jersey-20
http://java.dzone.com/articles/whats-new-jax-rs-20

gp:cacheControl and lda:uriTemplate

gp:cacheControl, lda:uriTemplate and similar should probably be OWL annotation properties, attached directly to resource classes instead of restrictions. It makes no sense for the actual instance data to contain these properties anyway.

OWL annotations

Linked Data locators should know what RDF formats Jena supports

LocatorLinkedData and DataManager should dynamically retrieve supported RDF content types and syntaxes from Jena, instead of keeping own static constants

Search & autocomplete

Create org.graphity.browser.SearchResource (use SPIN API to replace regex() match string as RDF literal)

Pagination on Models

Pagination using QueryBuilder currently works on SPARQL endpoints only.

Apply the same mechanism on Linked Data resources and unify pagination using SPARQL OFFSET/LIMIT either on SPARQL endpoints or Resource Model.

Load sitemap and XSLT from remote Graphity instance

Right now the sitemap and the stylesheet are stored locally and configured in web.xml. They could be advertised via HTTP Link headers and loaded in run-time by the client from a remote Graphity instance, and then used for class matching and transformation as usual. This probably involves changes to OntologyProvider and XSLTBuilderProvider.

ConversionException

com.hp.hpl.jena.ontology.ConversionException: Cannot convert node http://purl.org/linked-data/api/vocab#uriTemplate to OntProperty at com.hp.hpl.jena.ontology.impl.OntPropertyImpl$1.wrap(OntPropertyImpl.java:68) at com.hp.hpl.jena.enhanced.EnhNode.convertTo(EnhNode.java:155) at com.hp.hpl.jena.enhanced.EnhNode.convertTo(EnhNode.java:34) at com.hp.hpl.jena.enhanced.Polymorphic.asInternal(Polymorphic.java:66) at com.hp.hpl.jena.enhanced.EnhNode.as(EnhNode.java:110) at com.hp.hpl.jena.ontology.impl.OntResourceImpl.objectAs(OntResourceImpl.java:1416) at com.hp.hpl.jena.ontology.impl.RestrictionImpl.getOnProperty(RestrictionImpl.java:122) at org.graphity.processor.model.ResourceBase.matchOntClass(ResourceBase.java:526) at org.graphity.processor.model.ResourceBase.matchOntClass(ResourceBase.java:493) at org.graphity.processor.model.ResourceBase.<init>(ResourceBase.java:192) at org.graphity.client.model.ResourceBase.<init>(ResourceBase.java:140) at org.graphity.client.model.ResourceBase.<init>(ResourceBase.java:113) at eu.refstock.ResourceBase.<init>(ResourceBase.java:41)

Basic generic analytics

Integrate report interfaces from semanticreports.com

SPIN query should accept query instances

Right now spin:query on resource classes only accepts template calls, such as [ a gp:DescribeInstanceTemplate ]. Queries should also be allowed here to make the behaviour consistent with SPIN API, e.g. [ a sp:Ask ; sp:text "ASK ..." ].
http://spinrdf.org/spin.html#spin-constraints

Remote Turtle resources do not load

At some point Turtle support was removed from LocatorLinkedData and DataManager due to content type constant changes in Jena's WebContent

Load Mode configuration from sitemap

Read properties gc:defaultMode and gc:mode attached to matched sitemap class to configure the layout modes in XSLT (instead of current static configuration in the stylesheet).

LocatorGRDDL

Integrate GRDDL Reader and implement a sample GRDDL stylesheet (for a popular API like Twitter)

Proxy all HTTP methods in client mode

Right now GlobalResourceBase proxies GET method only. The same should be done for POST, PUT, DELETE. HTTP access might have to be refactored on a lower Response level with Jersey Client API instead of current Jena-based DataManager, which works on RDF Model level.

XSLT extension functions

Need to implement a couple of Saxon integrated extension functions like g:decode-from-uri() and g:uuid().
The free open-source Saxon-HE version, does not support calling Java extension functions directly.

RDFa generation

RDFa markup could be automatically added to the current XHTML output (produced by XSLT transformations)

Empty property blocks should not be shown

Properties get grouped by domain type, but after applying templates some of them do not show up on the list.

Integrate specialized SPARQL editor

Provide a better editor for SPARQL syntax than the current <textarea>. For example YASGUI: http://laurensrietveld.nl/YASGUI-QueryEditor/index.html

Cache control config per resource class

Instead of a single value in web.xml, it should be possible to configure different Cache-Control values for resource classes based on URI templates. This can be done by attaching a value restriction to a resource class in the sitemap ontology.

Response EntityTag should depend on format

Right now the EntityTag is generated as a hash of the RDF response Model, which means all serializations, including XHTML, get the same value. This leads to caching issues (wrong response body returned on 304 Not Modified. The solution is to add serialization info to the hash.

Column ordering in g:TableMode

Ordering mechanism needs to be generic -- QueryBuilder must be able to combine ad hoc OPTIONAL and ORDER BY to build a parametrized SPARQL query

javax.servlet.ServletContainerInitializer class cast issues when running standalone client

Tomcat: 8.0.5
Java: 1.8.0_05
OS: Mac OSX 10.8.5
After mvn install graphity-ldp then graphity-browser

Deploy war graphity-browser/target/client-1.0.12-SNAPSHOT.war
Starting webapp gives:
org.apache.catalina.startup.ContextConfig.processServletContainerInitializers Failed to process JAR found at URL [/graphity] for ServletContainerInitializers for context with name [{1}]
java.io.IOException: java.lang.ClassCastException: Cannot cast com.sun.jersey.server.impl.container.servlet.JerseyServletContainerInitializer to javax.servlet.ServletContainerInitializer

Faceted browsing

Implement type filtering on lists by augmenting FILTER on SPIN query of the current Resource

Custom annotations like @Model("uri")

Instead of using @Context to inject custom objects, it would be nicer to have custom annotations that also accept arguments (like query param name): @Model("uri") @SPARQLEndpoint("endpoint-uri")

https://jersey.java.net/documentation/latest/ioc.html#d0e15107
http://avianey.blogspot.dk/2011/12/exception-mapping-jersey.html

Sitemap ontology based on POWDER

http://www.w3.org/TR/powder-formal/

Remote Linked Data resources do not load

GlobalResourceBase uses the wrong DataManager which reverts to FileManager and expects RDF/XML, doesn't do content negotiation

Problems with css loading

Hi,
I've deployed the browser to try to configure over some sparql enpoint .
After deployng the war, when I try to reach the browser page it seems to not load css styleshits. I tried to see if the path is correct (and it seems to be) but no css are loaded at all. So I view only the html parsed from the frontpage.xsl without style.

My graphity-browser URL is: http://localhost:8181/browser-1.0.0/ (as the name of the war)
The URL of referred for the stylesheets is: http://localhost:8181/graphity-browser/static/css/bootstrap.css and for this resource Tomcat tell me "The requested resource (Not Found) is not available."

Tomcat is 6.0.29.

What can I do?

First letter of labels made from URIs should not be uppercased

Only labels made from label metadata should be uppercased

ORDER BY in QueryBuilder can produce invalid queries

Currently it is possible to set an ORDER BY expression in QueryBuilder that uses a variable which is not present in the WHERE pattern. That will result in invalid SPARQL query. Exception should be thrown in this situation.

Map layout mode

Add generic gc:MapMode to XSLT stylesheets. By default it could recognize geo:lat and geo:long in the data and display markers on Google Maps

Serialize Exceptions to RDF

Probably needs a MessageBodyWriter<Exception> that would construct RDF model from exception metadata. It should work with existing ExceptionMappers.

Load Locale configuration from sitemap

Locale string values which are used to build Variant list could be read from sitemap class property like gp:language.

MessageBodyReader for RDF/POST

Refactor RDFForm

Integration with launch4j

Use launch4j to provide cross-platform executables
http://launch4j.sourceforge.net

XSLT parameter names as URIs

Change current XSLT stylesheet parameter names such as base-uri into absolute URIs in Graphity namespace, such as gc:BaseURI. They are set in ModelXSLTWriter.

Sitemap validation

Could be implemented as SPIN constraints and run on application startup

Resource being browser should appear on the top of the page

When $uri parameter is present, a special case is needed to display RDF description of resource with that URI as the first one on the page

UriBuilder for XSLT

Better way than concat() is needed to build URIs from components in XSLT/XPath, probably as an XPath function.

Right now, if $uri and $endpoint-uri are missing, one can end up with links such as http://localhost:8080/sparql&lang=ru, which naturally results in 404 since it's a different absolute path than http://localhost:8080/sparql.

QuerryBuilder.replaceXXX() methods should accept null arguments

Null arguments should clear the query property (such as ORDER BY modifier value) without adding anything new. This will make QueryBuilder more consistent with the UriBuilder design:
http://jackson.codehaus.org/javadoc/jax-rs/1.0/javax/ws/rs/core/UriBuilder.html#replaceQuery(java.lang.String)

LocatorGRDDL should be bound to URI templates

DataManager should only attempt to use LocatorGRDDL locator instance to read remote datasource when its URI matches the template specified in that locator

SKOS labels are not shown

SKOS template is not imported into main browser stylesheet(s)

ExceptionMapper with XSLT layout

ExceptionMappers should use XSLTBuilder to build user-friendly error pages (instead of default ones by Tomcat)

XHTML ETag needs to depend on mode and language

Should be easy to fix in ModelXSLTWriter.getXSLTBuilder()

406 Not Acceptable

Probably of the default XHTML media type, some browsers (IE, probably Safari) are not displaying the response

Sitemap URI templates do not accomodate both pagination and modes

More flexible URI templates necessary to match page URIs with query parameters: limit, offset, optional order-by, optional desc=true, and optional mode

Context path does not work as base URI?

The webapp should work with any context path (or without it) -- the URIs should be relative to the context path as the base

Language selection dropdown doesn't work

The templates are language-aware but the dropdown (in the top-right corner) does not work.
Bootstrap probably needs HTML5 doctype for AJAX functionality.