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api:dk11:activex:tatukgis_xdk11.tgis_layerwfs

TGIS_LayerWFS class

DK11 for ActiveX | TatukGIS_XDK11.TGIS_LayerWFS | Classes | Methods | Properties

Encapsulation of an OpenGIS WFS layer.

Available also on: Delphi | .NET | Java.

Syntax

// C#
public class TGIS_LayerWFS : ITGIS_LayerWFS, ITGIS_LayerEvents 
{
}
' VisualBasic
Public Class TGIS_LayerWFS
  Implements ITGIS_LayerWFS
  Implements ITGIS_LayerEvents
End Class
// Oxygene
type
  TGIS_LayerWFS = public class
  end;

Implements

Methods

Inherited Overrides Protected
Name Visibility Description
Add public Add a layer to the list.
(Inherited from ITGIS_LayerCompoundAbstract)
Alive public Makes a layer non-dormant.
(Inherited from ITGIS_Layer)
ApplyCuttingPolygon public Sets a cutting polygon for a layer.
(Inherited from ITGIS_Layer)
AttachDelphiObj public Only for internal use of TatukGIS.
(Inherited from ITBaseObject)
BusyEvent public
(Inherited from ITGIS_LayerEvents)
ChangeHash public Changes the hash for the purpose of verifying layer's modifications.
(Inherited from ITGIS_Layer)
ClearModified public Sets IsModified flag to false for a layer and its sublayers.
(Inherited from ITGIS_Layer)
DelphiObj public Only for internal use of TatukGIS.
(Inherited from ITBaseObject)
Dormant public Makes a layer dormant.
(Inherited from ITGIS_Layer)
DormantGain public Calculates the approximate gain (in Megabytes) which can be achieved by releasing memory by calling Dormant method.
(Inherited from ITGIS_Layer)
Draw public Draws a layer.
(Inherited from ITGIS_Layer)
DrawEx public Draws a layer within a defined extent.
(Inherited from ITGIS_Layer)
DrawFlash public Draws a flash.
(Inherited from ITGIS_Layer)
DrawSelected public Draws only the selected item(s) on layer.
(Inherited from ITGIS_Layer)
DrawSelectedEx public Draws only the selected item(s) on layer that are within a defined extent.
(Inherited from ITGIS_Layer)
ForEachSubLayer public Returns in callback event the layer and all sublayers belonging to it.
(Inherited from ITGIS_Layer)
Get public Retrieve the layer identified by a name.
(Inherited from ITGIS_LayerCompoundAbstract)
GetAvailableLayers public Gets a list of layers available in storage.
(Inherited from ITGIS_Layer)
HourglassShake public Notifies of busy state using an hourglass.
(Inherited from ITGIS_Layer)
IsGrid public Checks if the layer type is grid.
(Inherited from ITGIS_Layer)
IsPixel public Checks if the layer type is pixel.
(Inherited from ITGIS_Layer)
IsSupported public Checks if the operation is supported by the layer.
(Inherited from ITGIS_Layer)
IsVector public Checks if the layer type is vector.
(Inherited from ITGIS_Layer)
IsVector3D public Checks if the layer type is vector 3D.
(Inherited from ITGIS_Layer)
IsVisible public Checks if the layer is visible in a defined extent and current params.
(Inherited from ITGIS_Layer)
LocateEx public Locate a shape (more precise).
(Inherited from ITGIS_LayerCompoundVector)
LocateEx_2 public Locate a shape (more precise).
(Inherited from ITGIS_LayerCompoundVector)
Lock public Locks layer in burst-mode operation.
(Inherited from ITGIS_Layer)
Move public Moves a layer up or down in the viewer zorder list.
(Inherited from ITGIS_Layer)
MoveEx public Moves a layer up or down in the viewer zorder list (only visible layers).
(Inherited from ITGIS_Layer)
MustCalculateStatistics public Verifies if all statistics required to properly render the layer are available.
(Inherited from ITGIS_Layer)
MustReproject public Checks if the layer must be reprojected.
(Inherited from ITGIS_Layer)
MustSave public Checks if the layer was modified by editing.
(Inherited from ITGIS_Layer)
Open public Opens the layer.
(Inherited from ITGIS_Layer)
Paint public Draws the layer or fires PaintLayer event (if defined).
(Inherited from ITGIS_Layer)
PaintLayerEvent public
(Inherited from ITGIS_LayerEvents)
PasswordEvent public
(Inherited from ITGIS_LayerEvents)
Prepare public Opens the layer.
(Inherited from ITGIS_Layer)
PreRecognize public Checks if the layer can read the file.
(Inherited from ITGIS_Layer)
Project public Applies a projection on the single point.
(Inherited from ITGIS_Layer)
Project3D public Applies a projection on the single point in 3D.
(Inherited from ITGIS_Layer)
Project3D_Ref public Applies a projection on the single point in 3D.
(Inherited from ITGIS_Layer)
ProjectExtent public Applies a projection on the extent.
(Inherited from ITGIS_Layer)
Project_Ref public Applies a projection on the single point.
(Inherited from ITGIS_Layer)
RaiseBusyEvent public Fires Busy event of the layer.
(Inherited from ITGIS_Layer)
RaiseBusyPrepare public Fires BusyPrepare method of the assigned viewer.
(Inherited from ITGIS_Layer)
RaiseBusyRelease public Fires BusyRelease method of the assigned viewer.
(Inherited from ITGIS_Layer)
RaiseBusyShake public Fires BusyShake method of the assigned viewer.
(Inherited from ITGIS_Layer)
ReadConfig public Reads the layer configuration files.
(Inherited from ITGIS_Layer)
ReadConfigParam public Reads the layer configuration parameters.
(Inherited from ITGIS_Layer)
ReadEvent public
(Inherited from ITGIS_LayerEvents)
RecalcExtent public Recalculates extent based on real shapes.
(Inherited from ITGIS_Layer)
RecalcProjectedExtent public Recalculates a projected extent.
(Inherited from ITGIS_Layer)
ReOpen public Reopens the layer.
(Inherited from ITGIS_Layer)
RereadConfig public Rereads the layer configuration files.
(Inherited from ITGIS_Layer)
RevertAll public Reverts layer to its original content.
(Inherited from ITGIS_Layer)
RootLayer public Returns the absolute parent layer.
(Inherited from ITGIS_Layer)
SaveAll public Saves layer and destroys mirrored items.
(Inherited from ITGIS_Layer)
SaveData public Saves layer and destroys mirrored items.
(Inherited from ITGIS_Layer)
SetCSByEPSG public Sets up Coordinate System to a coordinate system provided by a EPSG code.
(Inherited from ITGIS_Layer)
SetCSByWKT public Sets up Coordinate System to a coordinate system provided by a WKT string (GEOGCS or PROJCS).
(Inherited from ITGIS_Layer)
SetCSByWKTFile public Sets up Coordinate System to a coordinate system provided by a file which contains a WKT string (GEOGCS or PROJCS).
(Inherited from ITGIS_Layer)
Unlock public Unlocks layer from burst-mode operation.
(Inherited from ITGIS_Layer)
Unproject public Applies reverse projection (recovers from the projection) on the single point.
(Inherited from ITGIS_Layer)
Unproject3D public Applies reverse projection (recovers from the projection) on the singlepoint in 3D.
(Inherited from ITGIS_Layer)
Unproject3D_Ref public Applies reverse projection (recovers from the projection) on the single point in 3D.
(Inherited from ITGIS_Layer)
UnprojectExtent public Applies reverse projection (recovers from the projection) on the extent.
(Inherited from ITGIS_Layer)
Unproject_Ref public Applies reverse projection (recover from projection) on the single point.
(Inherited from ITGIS_Layer)
WriteConfig public Writes layer configuration files.
(Inherited from ITGIS_Layer)
WriteEvent public
(Inherited from ITGIS_LayerEvents)

Properties

Inherited Protected
Name Visibility Description
Active public Checks if the layer is active? Active means layer is visible and an object can be localized on the layer.
(Inherited from ITGIS_Layer)
Addition public Additional value.
(Inherited from ITGIS_Layer)
Age public Age of the layer (since its creation).
(Inherited from ITGIS_Layer)
Basemap public True if the layer must be interpreted as basemap (for background painting).
(Inherited from ITGIS_Layer)
CachedPaint public False if layer must be painted directly (bypassing cache).
(Inherited from ITGIS_Layer)
Caption public Caption of layer; if not filed directly then will be filed with Name when adding to the Viewer.
(Inherited from ITGIS_Layer)
CodePage public Code Page in which text has been stored.
(Inherited from ITGIS_Layer)
Collapsed public Checks if the layer is collapsed? Collapsed means only the layer's title will be visible inside the legend.
(Inherited from ITGIS_Layer)
Comments public Additional user comments.
(Inherited from ITGIS_Layer)
ConfigFile public Configuration file handle.
(Inherited from ITGIS_Layer)
ConfigName public Configuration file name.
(Inherited from ITGIS_Layer)
CS public Coordinate System that is assigned to the layer.
(Inherited from ITGIS_Layer)
CustomData public List of custom, user-defined data.
(Inherited from ITGIS_Layer)
DirectMode public True if the layer is direct-mode (bypassing cache).
(Inherited from ITGIS_Layer)
DormantMode public Dormant mode for the layer.
(Inherited from ITGIS_Layer)
Driver public The layer's driver name.
(Inherited from ITGIS_Layer)
Extent public Extent of the layer.
(Inherited from ITGIS_Layer)
Extent3D public Three-dimensional extent of the layer.
(Inherited from ITGIS_Layer)
FileCopyrights public Copyright information about the layer.
(Inherited from ITGIS_Layer)
FileInfo public Additional textual information about the layer such as compression, number of pixels, copyright, etc.
(Inherited from ITGIS_Layer)
FoundLayers public List of all found layers names.
HideFromLegend public False if the layer should not be visible in legend.
(Inherited from ITGIS_Layer)
IsExportable public True if the layer is exportable.
(Inherited from ITGIS_Layer)
IsLocked public True if the layer is in locked state.
(Inherited from ITGIS_Layer)
IsOpened public True if the layer is opened and is ready for operations.
(Inherited from ITGIS_Layer)
IsPersistent public True if the layer is persistent.
(Inherited from ITGIS_Layer)
IsReadOnly public True if the layer is read-only.
(Inherited from ITGIS_Layer)
IsTopmost public True if the layer can be interpreted as the topmost (trackable) layer.
(Inherited from ITGIS_Layer)
Layer public All sub layers.
(Inherited from ITGIS_LayerCompoundAbstract)
LayersCount public Sub layers count.
(Inherited from ITGIS_LayerCompoundAbstract)
MaxTileSize public Maximum allowed tile size for the layer.
(Inherited from ITGIS_Layer)
MultiUserMode public Type of multiuser mode.
(Inherited from ITGIS_Layer)
Name public Name of layer; if not filled directly, then will be filled with Path when added to the viewer.
(Inherited from ITGIS_Layer)
ParamsList public List of all parameter sections attached to the current layer.
(Inherited from ITGIS_Layer)
Params_ public Parameters (colors, fills, etc.) object.
(Inherited from ITGIS_Layer)
ParentLayer public Parent layer of a sub layer.
(Inherited from ITGIS_Layer)
Path public Path to file holding the layer's data.
(Inherited from ITGIS_Layer)
PathWithDriver public Path to file with the layer's data extended with driver name.
(Inherited from ITGIS_Layer)
ProjectedExtent public Extent of the layer in projected units.
(Inherited from ITGIS_Layer)
ProxyUrl public Proxy URL as for ESRI proxy.ashx.
Renderer public Handle to a renderer used for drawing shapes.
(Inherited from ITGIS_Layer)
Statistics public Layer statistics engine
(Inherited from ITGIS_Layer)
Stream public Reference to a potential layer underlying the stream.
(Inherited from ITGIS_Layer)
SubLayers public List of sublayers belonging to the layer.
(Inherited from ITGIS_Layer)
SubType public Type of sublayer.
(Inherited from ITGIS_Layer)
Tag public Tag has no predefined meaning.
(Inherited from ITGIS_Layer)
TagInternal public TagInternal has no predefined meaning.
(Inherited from ITGIS_Layer)
TagPointer public TagPointer has no predefined meaning.
(Inherited from ITGIS_Layer)
Transform public Custom transformation.
(Inherited from ITGIS_Layer)
Transparency public Transparency value for the layer (0..100).
(Inherited from ITGIS_Layer)
UnSupportedOperations public Set of operations not supported by the layer.
(Inherited from ITGIS_Layer)
UseConfig public True if config file is active.
(Inherited from ITGIS_Layer)
UseLayers public List of layers to be used for render.
UserAgent public User Agent string.
UserObject public UserObject can be used to associate with the layer a user-defined object.
(Inherited from ITGIS_Layer)
Viewer public Reference to a viewer object.
(Inherited from ITGIS_Layer)
ZOrder public Layer's position relative to other layers.
(Inherited from ITGIS_Layer)
ZOrderEx public Layer position relative to other visible layers.
(Inherited from ITGIS_Layer)

Remarks

To open a layer provide the path with GetResponse request like

 Layer.Path := ‘http://WFS.jpl.nasa.gov/WFS.cgi?SERVICE=WFS&REQUEST=GetCapabilities’ ;

This layer can also be opened by opening the file name_of_layer.ttkwp or embedding all parameters to Path property as CRLF or '\n' delimited string. Structure of this file must be:

  [TatukGIS Layer]
  Storage=WFS
  Name=layer name
  Caption=layer caption
  Url=wfs server url
  .....
  AxisOrder=NE or EN (default) (obsolate)
  AxisOrderReversed=reverse coordinates of axis for some coordinate systems
  AxisOrderIgnored=ignore axis order from the coordinate system (only for 1.3.0 services)
  ExtentOrder=set XX or XY to define how a bounding box of a layer is defined
  PagingEnabled=True|False request data in pages (default false)
  PageSize=number of features per page (default 1000)

If the GetCapabilities will be omitted then the class will try to recognize the server of its own:

  Layer.Path := 'http://WFS.jpl.nasa.gov/WFS.cgi?SERVICE=WFS' ;

Parameters

It is possible to embed into Path additional WFS parameters like VERSION, TYPENAME, SRSNAME, OUTPUTFORMAT, MAXFEATURES, STARTINDEX, BBOX, CQL_FILTER, AxisOrderIgnored, AxoisOrderReversed, ExtentOrder, PAGINGENABLED or PAGESIZE like

  layer.Path := 'http://WFS.jpl.nasa.gov/WFS.cgi?SERVICE=WFS&FORMAT=image/jpeg&LAYERS=global_mosaic' ;

For WFS servers that require authentication, it is possible to embed into Path additional parameters USER, PASS like

  layer.Path := 'http://WFS.jpl.nasa.gov/WFS.cgi?SERVICE=WFS&USER=test&PASS=test' ;

or use templates format instead of real parameter values and OnPassword event for secured decoding like

  layer.Path := 'http://WFS.jpl.nasa.gov/WFS.cgi?SERVICE=WFS&USER=<#USER#>&PASS=<#PASS#>' ;

Axis order

The layer should properly recognize axis order. However, axis order can be modified to:

  • force reversed axis order useAxisOrderReversed=true definition and:
    • embed into a URL
    • store in a .ttkwp file
    • store in a layer configuration file or project file
    • use Metadata TGIS_LayerWFS.AxisOrderReversed=true
  • ignore axis order recognition use AxisOrderIgnored=true definition and:
    • embed into a URL
    • store in a .ttkwp file
    • store in a layer configuration file or project file
    • use Metadata TGIS_LayerWFS.AxisOrderIgnored=true

Paging

For big datasets, users can enable Paging that allows reading the data in chunks defined by page size. This is a preferred solution to avoid timeouts from a server. The Paging can be enabled by adding PagingEnabled and PageSize to a URL, .ttkwp file, or using Metadata TGIS_LayerWFS.PagingEnabled and TGIS_LayerWFS.PageSize.

Fetching data

To avoid blocking a layer during the opening of a project, after the initial setup a layer is empty. The data is fetched upon calling Draw on the layer.

2020/09/15 01:02

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