Client Views Projections

Owned by Shaun Forbes
Last updated: 26 Apr, 2022
2 min read

Provides a means of displaying the current cursor position in different projections.

Note that you need to know the Proj4 definition of the alternate projections you wish to display.

ID

com.cohga.html.client.main.projView

Sub-tags

Name

type

cardinality

description

label

String

0..1

Label to display in tab

location

String

1..1

Which region to add the view to

projection

String

1..n

The definitions and labels of the projections to display

serverBoolean0..1If the transformation should be undertaken on the server, which is the case if the transform will require a grid shift

Example

<view id='com.cohga.html.client.main.projView'>
        <label>Projections</label>
        <location>west</location>
        <projection id="EPSG:28354" label="GDA94/MGA Zone 54"/>
        <projection id="EPSG:28355" label="GDA94/MGA Zone 55"/>
        <projection id="EPSG:28356" label="GDA94/MGA Zone 56"/>
        <projection id="EPSG:20254" label="AGD66/AMG Zone 54"/>
        <projection id="EPSG:20255" label="AGD66/AMG Zone 55"/>
        <projection id="EPSG:20256" label="AGD66/AMG Zone 56"/>
<!--
The following three entries show examples of how a custom transform can be specified.
This does NOT have to be done if you want to use any of these three projections, it's just done here to show you how you could do it.
-->
        <projection id="EPSG:4283" label="GDA94">
                <def>+proj=longlat +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +no_defs</def>
        </projection>
        <projection id="EPSG:3111" label="VicGrid94">
                <def>+proj=lcc +lat_1=-36 +lat_2=-38 +lat_0=-37 +lon_0=145 +x_0=2500000 +y_0=2500000 ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs</def>
        </projection>
        <projection id="EPSG:3112" label="GDA94/Geoscience Australia Lamberts"/>
                <def>+proj=lcc +lat_1=-18 +lat_2=-36 +lat_0=0 +lon_0=134 +x_0=0 +y_0=0 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs</def>
        </projection>
</view>

Coordinate transformations using the server

<!-- This example shows a client defined in GDA2020 and reporting coordinates in GDA94 -->
<view id='com.cohga.html.client.main.projView'>
        <label>Projections</label>
        <location>west</location>
        <!-- The following definitions will do the transformation on the server using the NTV2 transformation from GDA2020 to GDA94 -->
		<projection id="EPSG:28354" label="GDA94/MGA Zone 54" server="true"/>
        <projection id="EPSG:28355" label="GDA94/MGA Zone 55" server="true"/>
        <projection id="EPSG:28356" label="GDA94/MGA Zone 56" server="true"/>
		<projection id="EPSG:3111" label="GDA94/VicGrid94" server="true"/>
		<projection id="EPSG:4283" label="GDA94" server="true"/>
		
		<!-- The following two definitions will do the transformation in the browser as the map datum is already in GDA2020 -->
		<projection id="EPSG:7844" label="GDA2020"/>
		<projection id="EPSG:7855" label="GDA2020/MGA Zone 55"/>
</view>