As of Weave 2.6.6, it’s possible to define filters that can be associated with a map layer. The filters are used when the layer is drawn to refine the set of features that will be rendered for the layer. Additionally, a new client panel allows the user to dynamically alter the filter, giving them the ability to dynamically refine the features displayed on the map.

This is similar to the search panel where the user can enter certain criteria to select a set of entities, but in this case, the input the user enters is used to refine the set of features displayed on the map. For example, if the map contains a layer representing the public reserves, a filter could be created for the reserves layer that allows the user to display only those reserves containing a specific facility or facilities, i.e. only those reserves with barbeques and/or public toilets.

The panel to include in the client to allow the user to alter the filters has the id weave.layerFilter.

The client UI for the filtering contains a couple of new controls that were not previously available with other input forms, the slider and multi-slider. These controls are useful for layer filtering because they provide an easier way to constrain a numeric value to a certain range. But they’re also different in that they force a value to be chosen, that is a filter that uses a slider for a value will always have that value applied when displaying the layer. This can be important when the table behind the layer contains a number of “sets” of data but only one should be displayed at a time, and the column behind the parameter is used to separate out the data into the various sets. An example of this could be the year when the data in the table was generated and the user would only want to see a single year at a time, or for a layer with flood levels and you only want to show a single depth.

In addition to the filter panel, there is also a ToC panel context menu item, weave.toc.filterLayer. This can be added to the ToC panel context menu to allow the user to filter a layer directly. It’s recommended that the layer filtering capability is provided either in the filter panel or context menu in a client and not both (as providing both could result in display synchronisation issues).

Finally, there is a new flag available for the ToC panel, showFilterIcon, which when set to true will place an indicator icon next to a layer in the ToC that currently has a filter applied.

Current limitations

There can be only one filter associated with a particular map layer, this is unlikely to change.

The filtering only affects the display of the layer on the map, it plays no part for example if the user tries to spatially select entities that are associated with that layer (this may change depending upon demand) or when displaying a legend.

Configuration

Namespace

urn:com.cohga.weave.map.filter#1.0

Tags

layer

Properties

Name	Type	Required	Description
id	string	yes	Unique identifier for this filter
label	string	yes	Text to be displayed to the user to represent this filter
mapengine	string	yes	The identifier of the map engine the layer to filter belongs to
layer	string	yes	The identifier of the layer in the map engine this filter applies to

Sub-tags

Name	Type	Cardinality
parameter	urn:com.cohga.weave.map.filter#1.0:parameter	1..n

parameter

Properties

Name	Type	Required	Default	Description
id	string	yes		A unique identifier for the parameter
label	string	yes		The prompt text displayed when user input the parameter value
column	string	yes		The name of the column within the layer that this parameter references.
controlType	'text', '‘list', 'radio', ‘check', ‘multicheck’, 'silder’, 'multislider’	no	'text'	The UI control to use when displaying the parameter
dataType	'boolean', 'float', 'integer', 'string'	no	'string'	The data type for the parameter
allowBlank	boolean	no	true	Give the user the choice of an empty value in the listbox (as opposed to a null value)
value	any	no		The default value of the parameter (except multislider fields)
dataSet	ref urn:com.cohga.server.data.database#1.0:datadefinition	no		Where to get the values for a listbox
labelColumn	string	no		Column in the datadefinition that supplies the label of the value to show the user
valueColumn	string	no		Column in the datadefinition that supplies the value of the value to use in the SQL
scalarparametertype	string	no	'simple'	'simple' or 'multi-value' to determine of more than one value can be selected from a list.
width	integer	no		Set the width of the field
minValue	number	yes - for slider and multislider		The minimum value allowed for a numeric field.
maxValue	number	yes - for slider and multislider		The maximum value allowed for a numeric field.
leftValue	number	no		The initial minimum value for a multislider
rightValue	number	no		The initial maximum value for a multislider
increment	number	no		The increment to use for fields that support it, the units are dependant upon the field type.
trueValue	any	no		The value that equates to "true" in the underlying table, only suitable for checkboxes
falseValue	any	no		The value that equates to "false" in the underlying table, only suitable for checkboxes
decimalPrecision	number	no		The precision of any numeric fields

Sub-tags

Name	Type	Cardinality
list	urn:com.cohga.weave.map.filter#1.0:list	1..1 - only for radio and multicheck fields

list

Properties

Name	Type	Required	Description
value	string	yes	Value to be used in the filter
label	string	yes	Text to be displayed to the user to represent this filter
checked	string	no	Should this check box be initially checked. Only for list within multicheck field

Examples

<?xml version="1.0" encoding="UTF-8"?>

<config xmlns="urn:com.cohga.server.config#1.0"
        xmlns:mapfilter="urn:com.cohga.weave.map.filter#1.0"
        xmlns:data="urn:com.cohga.server.data.database#1.0">

  <!-- provide the values for the title names list -->
  <data:datadefinition id="titles.names">
    <datasourcedataconnection datasource="main" table="TITLES" prefix="DISTINCT">
      <parameter name="title_name" label="Title Name" column="TITLENAME"/>
    </datasourcedataconnection>
  </data:datadefinition>

  <!-- create a simple list parameter to filter on title name -->
  <mapfilter:layer id="titles">
    <label>Titles</label>
    <mapengine>main</mapengine>
    <layer>titles</layer>
    <parameter id="name" label="Name" controlType="list" scalarParameterType="multi-value"
      dataSet="titles.names" column="TITLENAME"/>
  </mapfilter:layer>

</config>

<!-- parameter examples -->

<!-- a parameter representing a floating point value between 2.5 and 26 with an increment of 0.5
and default value of 13 -->
  <parameter id="level">
    <label>Level (m)</label>
    <controlType>slider</controlType>
    <dataType>float</dataType>
    <column>Level_mGH</column>
    <minValue>2.5</minValue>
    <maxValue>26</maxValue>
    <value>13</value>
    <increment>0.5</increment>
    <decimalPrecision>1</decimalPrecision>
  </parameter>

<!-- a parameter representing an integer value between 2011 and 2019 inclusive 
with a default minimum of 2015 and default maximum of 2018 -->
  <parameter id="study_year">
    <label>Study Year</label>
    <controlType>multislider</controlType>
    <dataType>int</dataType>
    <column>Study_year</column>
    <minValue>2011</minValue>
    <maxValue>2019</maxValue>
    <leftValue>2015</leftValue>
    <rightValue>2018</rightValue>
  </parameter>

<!-- multiple grouped check boxes. Note in this case all checked boxes start as checked
but if none of the check boxes are checked all items would be displayed as well -->
  <parameter id="location">
    <label>Location</label>
    <controlType>multicheck</controlType>
    <column>Location</column>
    <dataType>string</dataType>
    <list label="Catchment, Todd" value="Todd Catchment" checked="true"/>
    <list label="River, Adelaide" value="Adelaide River" checked="true"/>
    <list label="River, McArthur" value="McArthur River" checked="true"/>
  </parameter>

<!-- single check box. Note in this case since we've set a different true value
when this check box is checked the filter applied will be "Location='Adelaide River'"
rather than "Location=true" as would be the case if trueValue were not set -->
  <parameter id="location">
    <label>Adelaide River Only</label>
    <controlType>check</controlType>
    <column>Location</column>
    <dataType>string</dataType>
    <trueValue>Adelaide River</trueValue>
  </parameter>

<!-- radio button -->
  <parameter id="location">
    <label>Location</label>
    <controlType>radio</controlType>
    <column>Location</column>
    <dataType>string</dataType>
    <value>Adelaide River</value>
    <list label="Catchment, Todd" value="Todd Catchment"/>
    <list label="River, Adelaide" value="Adelaide River"/>
    <list label="River, McArthur" value="McArthur River"/>
  </parameter>

<!-- list box -->
  <parameter id="location">
    <label>Location</label>
    <controlType>list</controlType>
    <dataSet>locations</dataSet>
    <column>Location</column>
    <dataType>string</dataType>
  </parameter>

<!-- a basic text box. Note this format is discouraged as the user has no way of knowing 
if the value they're entering is valid and may result in nothing being displayed -->
  <parameter id="location">
      <label>Location</label>
      <controlType>text</controlType>
      <column>Location</column>
    <dataType>string</dataType>
  </parameter>

Client

	<client:config id="filtering">
		<title>Example Filtering client</title>

		<!-- other config here -->

		<view id="weave.layerFilter">
			<location>east</location>
		</view>

		<!-- other config here -->

		<view id="com.cohga.html.client.map.tocView">
			<location>west</location>
			<label>Layers</label>
			<showFilterIcon>true</showFilterIcon>
			<contextmenu>
				<item action="weave.toc.filterLayer"/>
			</contextmenu>
		</view>

	</client:config>

Weave System Administrator Guides

Layer Filtering

Configuration

Namespace

Tags

layer

Properties

Sub-tags

parameter

Properties

Sub-tags

list

Properties

Examples