new PieChart(config)
This class represents a Pie chart style.
Parameters:
Name | Type | Description |
---|---|---|
config |
Object | A configuration object for PieChart. It can have the following attributes.
|
Returns:
An instance of OM.style.PieChart
- Type
- OM.style.PieChart
Extends
Methods
-
bindData(attribute, column, formatter)
-
Binds a Column data set to a specified aspect of this style. This creates
a single binding on this style instance. Check individual sub-styles to
see how many bindings they support.
Each binding is comprised of three key pieces: the style attribute being
bound, the Column data set that drives the style attribute, and a resolver
function that computes and returns an effective style attribute for any
given data value from the Column.Parameters:
Name Type Description attribute
string the name of the style attribute to be bound to a data Column. An
attribute is a visual aspect of the style, such as "Fill",
"Size" etc.column
object A data column (typically an instance of OM.Column) that will
format the specified visual attribute of the style. If a String type
value is passed in, then it is assumed to be the name of
an property in the target VectorLayer's features.formatter
object an instance of OM.style.Formatter; it
maps an individual item's value (such as sales volume) to a
particular visual style attribute value (such as a color).- Inherited From:
-
draw(feature, mapContext, options)
-
The actual logic for drawing a feature using a style is implemented in this method.
Must be overidden by sub-classes.Parameters:
Name Type Description feature
OM.Feature the feature to be applied with this style
mapContext
OM.MapContext the current map context
options
Object the rendering options, typically the graphics group
- Inherited From:
- Overrides:
Returns:
- Type
- undefined
-
getBindables()
-
Returns a list of bindable style attributes. A bindable attribute is
a certain aspect of a style (such as its fill color, stroke width or
overall size) that can be changed based on some business data value
associated with each feature. It is typically bound to a Column data
set.- Inherited From:
- Overrides:
Returns:
an array containing names of bindable attributes; if
no bindable attribute exists then an empty array is
returned.- Type
- Array
-
getConfig()
-
Gets the config of style.
- Inherited From:
Returns:
the config object
-
getStyleName()
-
Return the style name
- Inherited From:
Returns:
the style name
-
hasBinding()
-
Checks if this style has associated data bindings.
- Inherited From:
Returns:
true if there is one or more data bindings; false otherwise
- Type
- Boolean
-
isBindable(attr)
-
Checks whether a specified style attribute is bindable.
Parameters:
Name Type Description attr
String the name of the attribute to be checked
- Inherited From:
Returns:
true if the argument is bindable; false otherwise
- Type
- Boolean
-
isBound()
-
Checks whether a specified (bindable) attribute is already bound to some
Column data set.- Inherited From:
-
isFeatureBound(feature)
-
Checks whether the given feature is bound to any of the bindings in
this style.Parameters:
Name Type Description feature
OM.Feature the feature instance to be checked
- Inherited From:
Returns:
returns true if the feature has associated values from
any of the style bindings' Column instances. Returns false if there
is no values associated with this feature, or there is no bindings
at all in this style.- Type
- Boolean
-
resolveBinding(b, feature)
-
Resolves a specified binding for a given feature.
When a Style object has one or more of its visual attributes (such as Size
for a Marker style or Fill for a Color style) bound to an external data
column, then such visual attributes must be resolved for each and every feature
using the feature's associated data column value. The resolved visual
attribute values are then used to apply the style to that feature.In other words, each time this method is called against a specific feature,
the following process always takes place:- the feature's unique id is obtained
- the id is then used by the binding to find the corresponding data
value from the associated Column instance
- the data value is used to determine or resolve the visual attribute
of this style such as Size or Fill color.
- the visual attribute value is set on this Style instance for the
duration of rendering the feature.
Parameters:
Name Type Description b
Object the binding object
feature
Object the feature to be resolved with
- Inherited From:
Returns:
the resolved style attribute
- Type
- Object
- the feature's unique id is obtained
-
unbindAllData(attribute)
-
Un-binds all Column data sets currently bound to the specified style attribute.
Parameters:
Name Type Description attribute
String the name of the style attribute
- Inherited From:
-
unbindData(attribute)
-
Un-binds all Column data set for the given attribute.
Parameters:
Name Type Description attribute
String name of the style attribute (such as 'Fill', 'Size'
- Inherited From: