GXP

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GXP Webmapping made easy (we hope) FOSS4G,
Sept 14th 2011 Bart van den Eijnden, OpenGeo
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Contents

• - What is GXP?
• - What is ReadyGXP?
• - Architecture
• - Layer sources
• - Tools
• - So where's the easy part?
• - Further reading

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What is GXP?

• - Client-side only library written in javascript
• - Built on top of OpenLayers, Ext, GeoExt
• - Application framework for the OpenGeo Suite
• - Uses the Ext plugin architecture extensively

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Ext plugins

• Any component can now be extended through the use
  of plugins. A plugin is any class with an init
  method that accepts a single parameter of type
  Ext.Component. Plugins can be added into any
  Component via the plugins config option. When a
  component is created, if any plugins are
  available, the component will call the init
  method on each plugin, passing a reference to
  itself. Each plugin can then call methods or
  respond to events on the Component as needed to
  provide its functionality.

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What is GXP?

• - Leverages GeoServer and its extensions
• - Configuration should be JSON only (can be
  persisted easily)
• - Governed by OpenGeo, not by a PSC
• - Participation outside of OpenGeo is very much
  welcomed (pull requests)
• - GPL license

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Project statistics

• Project start June 2009
• 22k lines of code (OL 138k, GeoExt 29k)
• 8k lines of comments
• Lots of growth in 2010 and 2011

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Project statistics - GXP
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Project statistics - OpenLayers
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Project statistics - GeoExt
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What is ReadyGXP?

• - Utility to set up a development environment
• - Build static app for production
• - Simple back-end functionality (persistence,
  template rendering)

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Getting started is easy

• curl -L https//github.com/opengeo/readygxp/raw/ma
  ster/readygxp.sh sh -s myviewer
• ant init
• ant debug

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Architecture
Viewer
LayerSource
Tool
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Architecture

• - Central object is gxp.Viewer
• - All layer sources extend gxp.plugins.LayerSource
  
• - All tools extend gxp.plugins.Tool
• - Tools can have actions and output

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gxp.Viewer

• - portalConfig (Ext layout configuration)
• - tools
• - sources
• - map (projection, layers etc.)

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Supported layer sources

• GoogleSource
• BingSource
• OSMSource
• MapBoxSource

• MapQuestSource
• WMSSource
• WMSCSource
• OLSource

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WMSSource

• - Handles the WMS DescribeLayer and WFS
  DescribeFeatureType requests automatically, so
  that the WMS is tied to the WFS
• - WMSCSource makes use of the integration between
  GeoServer and GeoWebCache (TILEDTRUE parameter)

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Tools

• Add Layers
• Zoom to extent
• Get Feature Info
• Measure
• Google Earth
• Google Geocoder
• Google Streetview

• LayerTree
• Print
• Styling
• Query builder
• Snapping
• Feature editing
• Feature grid

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So where's the easy part?

• ptype "gxp_wmsgetfeatureinfo",
• outputConfig
• width 400

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So where's the easy part?

• ptype "gxp_legend",
• outputTarget "legendpanel"

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So where's the easy part?

• ptype "gxp_googlegeocoder",
• outputTarget "geocoder",
• outputConfig
• emptyText "Search for a location ..."

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Google layer

• sources
• google
• ptype "gxp_googlesource"

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Google layer

• map
• layers
• source "google",
• name "ROADMAP",
• group "background"

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Setting up editing

• ptype "gxp_featuremanager",
• id "states_manager",
• paging false,
• layer
• source "local",
• name "usastates"

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Setting up editing

• ptype "gxp_featureeditor",
• featureManager "states_manager",
• autoLoadFeatures true

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Setting up editing
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Setting up snapping

• ptype "gxp_snappingagent",
• id "snapping-agent",
• targets
• source "local",
• name "usastates"

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Setting up snapping

• ptype "gxp_featureeditor",
• featureManager "states_manager",
• autoLoadFeatures true,
• snappingAgent "snapping-agent"

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Feature grid
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Styling
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Resources

• https//github.com/opengeo/gxp
• https//github.com/opengeo/readygxp
• http//gxp.opengeo.org/master/doc/
• http//gxp.opengeo.org/master/examples/
• http//workshops.opengeo.org/gxp/

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Screencast
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Questions?
OpenGeo 1-877-OPENGEO http//www.opengeo.org bartv
de_at_opengeo.org