Common Web Map Client

The Common Web Map (CWM) client supports displaying and interacting with information on a map in a web browser.


Zoom In

Click to zoom the map in by one scale increment.

Zoom Out

Click to zoom the map out by one scale increment.

Zoom To BC

Click to zoom the map out to the extent of BC

Search

Click to display the Search for Location / Feature panel.

Search For Location

Search for a geographic location defined by a placename, address, mapsheet or coordinate.

The search type Auto automatically determines the location type from entered text, or a specific location type can be selected from the drop-down.

Locations are entered in the following ways:

Placename and address matching is case-insensitive and supports fuzzy matching.

Once the location type has been determined, Search Autocomplete shows matching location(s) in a list as text is entered.

Search For Features

Search for features on a layer spatially and by attribute value.

More than one attribute condition can be specified. Conditions are ANDed together.

When the Search layer and condition is specified, the search can be performed

The result features are displayed in the Searched Features sidepanel.

Bookmarks

Click to display the Bookmarks panel.

Bookmarks are named map extents which can be zoomed to. Bookmarks are saved in browser local storage.



AOI Geometry Toolbar

Click to display the Area Of Interest Geometry toolbar. This provides tools to create and manipulate geometry.

AOI Metrics

This panel is displayed when the AOI Toolbar is active.

It shows the Count, Area and Perimeter of the AOI geometries.

It lists the AOI geometries, and allows managing them with the following controls:

Zoom to AOI Geometry

Click to zoom the map to the current AOI geometry set.

Draw Rectangle

Draw a rectangle by clicking the mouse to set a corner and dragging out the extent. The rectangle is added as an AOI geometry.

Draw Polygon

Draws a polygon

Draw Line

Draws a line (linear path).

Draw Point

Draws a point.

Draw Circle

Draws a circle.

Edit AOI

Edits AOI geometries by adding, moving or deleting vertices.

Clear AOI

Click to clear all AOI geometries.

Undo Change

Click to undo a change to the AOI geometry.

Redo Change

Click to redo a change to the AOI geometry.

COGO

Click to display a panel to enter, display and edit geometry in COGO (Coordinate Geometry) format.

Import

Click to display a dialog to import geometries from a variety of spatial formats. The data format is auto-detected from the file type or data content.

Import geometry data in the following ways:

Tab From File

Tab From Data

The data projection (coordinate system) is auto-detected. If the coordinate system is UTM, the UTM Zone must be provided on the Choose Projection dialog. Choose the zone from a list, or by uploading a PRJ file.

Export

Click to display a dialog to export geometries in a variety of spatial formats. Geometry is exported in the geographic coordinate system (WGS84).


Geometry Calculator

Click to display a panel to perform calculations on geometries.

The display shows the Primary and Secondary AOI geometries defined.

Memory Save

Click to save the Primary geometry to memory.

Memory Recall

Click to recall the geometry from memory as a new geometry.

Memory Clear

Click to clears the geometry memory.

Union

Click to computes the geometric union of all geometries. The geometric union merges all geometries into a single geometry. The result geometry can be edited or have other calculations performed on it.

Intersect

Click to computes the geometric intersection of all geometries. The intersection is a geometry representing the common areas or lines of all the input geometries. The result geometry can be edited or have other calculations performed on it.

Subtract

Click to subtract the secondary geometries from the primary geometry. The result is a geometry which contains all the areas/lines/points which occur in the primary geometry but not in the secondary geometries. The result geometry can be edited or have other calculations performed on it.

Buffer

Computes a buffer polygon around the primary geometry to a specified distance. If the buffer distance is positive, the buffer expands (dilates) the geometry; if negative, it contracts (erodes) it.

  • Enter the buffer distance (in metres). The distance can be either positive or negative.
  • Click to replace the geometry with the computed buffer

Simplify

Reduces the number of vertices in a geometry while maintaining the approximate shape of the original geometry. Uses the Douglas-Peucker simplification algorithm, which requires a distance tolerance to control how many vertices are eliminated.

  • Enter a simplification distance tolerance (in metres)
  • Click to replace the geometry with the simplified version

Validate Topology

Click to check if the primary geometry is topologically correct. This detects if polygons contain self-intersections or overlaps. If a topology error is found an indicator is displayed showing the location of the error.

Close Polygon

Click to close a linestring to form a polygon.

Clean Polygon

Click to clean a polygonal geometry. This ensures that the geometry is a topologically valid polygon.

  • Dangling linework is closed and trimmed
  • Self-intersections are removed
  • Partially contained holes are excised


Markup

Click to display a toolbar to create Markup on the map.

Zoom to Markup

Click to zoom to the Markup geometries.

Draw Rectangle

Draw a rectangle by clicking the mouse to set a corner and dragging out the extent.

Draw Polygon

Draws a polygon.

  • Click the mouse to create vertices.
  • Double-click to complete the shape.
  • To draw using stream digitizing, hold Shift, click and drag the mouse.
  • To zoom in and out while drawing use the mouse wheel
  • To pan while drawing hold Ctrl, click and drag the mouse.

Set the symbology in the Style panel.

Draw Circle

Draws a circle.

  • Click to set the centre of the circle.
  • Drag and release to create the circle.
  • Set the symbology in the Style panel

Set the symbology in the Style panel.

Draw Line

Draws a line (linear path).

  • Click the mouse to create vertices.
  • Double-click to complete the shape.
  • To draw using stream digitizing, hold Shift, click and drag the mouse.
  • To zoom in and out while drawing use the mouse wheel
  • To pan while drawing hold Ctrl, click and drag the mouse.

Set the symbology in the Style panel.

Draw Point

Draws a point symbol with an icon, with an optional label and coordinate value.

  • Click the mouse to create a point
  • Optionally, enter the label text in the Style panel
  • Optionally, choose a Coordinate Format to display the location of the label point

Set the symbology in the Style panel.

Draw Label

Draws a label at a location, with an optional coordinate value.

  • Click to set the location of the label
  • Enter the label text in the Style panel
  • Optionally, choose a Coordinate Format to display the location of the label point.

Set the symbology in the Style panel.

Edit Markup

Click to allow selecting and editing Markup objects.

  • Click on a Markup object to select it for editing.
  • Drag the vertex control points to change the location of vertices
  • Drag the centre control point to move the object
  • Click outside the selected object to stop editing it.
  • Change the object symbology in the Style panel

Delete Markup

Click to delete the currently selected Markup object.

Clear Markup

Click to clear all Markup objects.

Markup Colour

Click to choose the colour for Markup objects.

Markup Line Style

Click to choose the line style for Markup shapes.

Markup Symbol

Click to choose the symbol for Markup points.

Markup Symbol Size

Click to choose the size for Markup symbols.

Markup Label Font

Click to choose the font for Markup labels.

Markup Label Size

Click to choose the text size for Markup labels.


Selection Toolbar

Click to display the Selection toolbar.

The selection set can contain features from multiple layers.

Choose the current selection layer from the layer dropdown. The layer must be visible at the current scale to be selected from.

Zoom to Selection

Click to zoom to the current selection.

Select by Box

Click and drag a box to add features from the current selection layer to the current selection.

Select by Polgyon

Click out a polygon to add features from the current selection layer to the current selection. Double-clicking closes the polygon and queries the selection layer for features.

Unselect by box

Click and drag a box to unselect features.

Unselect All

Click to unselect all features in the current selection.

Select by AOI

Click to select features using the current Primary AOI as the query polygon.

Display Selected Features

Click to display the Selected Features panel and view or manage the current selection set.


Measure Toolbar

Click to display the Measure toolbar. This provides tools to measure area and distance.

If an AOI geometry is present, the measure shape is initialized from it.

Measure Area

Click to draw an area to measure. Double-click to finish drawing. The area (in hectares) and perimeter (in kilometres) is displayed while drawing.

Be aware that if you make a line, the area will show as 0.0 ha, and the perimeter value will be twice the length of the line. You must insert at least 3 vertices to get a non-zero area. Use the distance measurement tool to measure the length of a line.

Measure Distance

Click to draw a linestring to measure. Double-click to finish drawing. The distance (in kilometres) is displayed while drawing.

Clear Measurement

Click to clear the current measurement.


Identify

Click a point on the map to Identify features at that point.

Identified features are shown in the Identify sidepanel.


Add Layer

Click to display a panel to add a map layer from a local data file. The layer title and styling can be specified. The new layer is displayed on the map positioned above the existing map layers.

Add a layer in either of the following ways:

Tab From File

Tab From Geomark

The data projection (coordinate system) is auto-detected. If the coordinate system is UTM, the UTM Zone must be provided on the Choose Projection dialog. Choose the zone from a list, or by uploading a PRJ file.

Title

Enter a title to use for the layer.

Style

Choose a colour to use for styling the layer.


Clear Highlight

Click to remove all highlighting from map. If any features on map have been highlighted, click this button to remove the highlights.


Save / Load Session

Click to display a dialog to save and load map sessions. Sessions are stored in *.session files.

When a session is loaded it replaces ALL user data layers which may be present.

Tab Save

Tab Load

Sessions contain the following data:


Layers

Click to display the Layers panel. It displays the active Overlays and Layers.

Overlays

An Overlay is a set of layers accessed from a single map service or data source.

Layers

A Layer is a styled feature class displayed on an overlay.

Layer panel

Click the layer name or the icon to display the Layer panel. The Layer panel provides controls to work with the layer.

Legend

Click to display the Legend panel. The Legend displays style symbology for visible layers.

Print

Click to display the Print dialog.


Coordinate Display

Displays the mouse location in the current coordinate format.

Coordinate Lock

Click to lock or unlock the Coordinate Display. When the display is locked, it will refresh only when the mouse is clicked on the map. This allows capturing the coordinates of a particular map location.

Graticule Control

Click to display or hide the graticule.

Base Map Chooser

Controls the display of the base map.


Concepts

AOI Geometry
A geometry (polygon, line or point) which delimits an Area of Interest shape used for querying or editing.
COGO
A way of specifying a geometric shape using a coordinate geometry description. A coordinate geometry description includes a start point, and a list of distances and bearings defining the line segments making up a line or polygon.
Coordinate System
(Also called Projection) The spatial reference system in which geometry or feature coordinates are represented. Supported Coordinate Systems include:
  • Geographic - may be Lat,Lon or Lon,Lat, in either Decimal degrees (DD) or Degrees-Minutes-Seconds (DMS) can be used.

    DD Example: 49.5, -125.4

    DM Example: 49 30', -125 20'

    DMS Example: 49 30' 45", -125 20' 30"

  • BC-Albers - uses X Y

    Example: 1047118 495805

  • UTM - uses X Y and Zone number

    Example: 329751 5483095 zone 10

Data Format
A way to encode spatial data in computer files. Supported data formats are:
  • KML (*.KML) - Keyhole Markup Language, used in Google Earth
  • GPX (*.GPX) - GPS Exchange format
  • GeoJSON (*.JSON) - Geometry expressed in Javascript notation
  • Well-Known Text (*.WKT) - a simple standard geometry format
  • Simple Text (*.TXT) - a text listing of the geometry coordinates
  • GeoMark - the URL or ID of a BC Government GeoMark

    Example: http://apps.gov.bc.ca/pub/geomark/geomarks/gm-abcdefghijklmnopqrstuvwxyz0000bc

    Example: gm-abcdefghijklmnopqrstuvwxyz0000bc

  • Shapefile (*.SHP) - the ESRI shapefile format
Layer
A set of features with a common business definition. Features in a layer have attributes with the same set of names, but possibly different values. Layers have an associated style which specifies how features are displayed on the map. Layer display may be scale-dependent, so that they only appear in a certain scale range.
Overlay
A set of layers accessed from a map service. Overlays may be turned on and off, and have their opacity changed.
Style
The set of graphical parameters that control how features on a layer are displayed.