Class: QgsRuleBasedLabeling¶

class qgis.core.QgsRuleBasedLabeling(root: QgsRuleBasedLabeling.Rule)¶

Bases: qgis._core.QgsAbstractVectorLayerLabeling

Constructs the labeling from given tree of rules (takes ownership)

New in version 3.0: Enums

Methods

`clone`
`create`	Create the instance from a DOM element with saved configuration
`requiresAdvancedEffects`
`rootRule`
`save`
`setSettings`	Set pal settings for a specific provider (takes ownership).
`settings`
`subProviders`
`toSld`
`type`
`writeTextSymbolizer`

Signals

Attributes

class Rule(settings: QgsPalLayerSettings, maximumScale: float = 0, minimumScale: float = 0, filterExp: str = '', description: str = '', elseRule: bool = False)¶

Bases: sip.wrapper

takes ownership of settings, settings may be None

New in version 3.0.

Filtered = 0¶

Inactive = 1¶

class RegisterResult¶: Bases: int

Registered = 2¶

active(self) → bool¶

Returns if this rule is active

Returns: True if the rule is active

appendChild(self, rule: QgsRuleBasedLabeling.Rule)¶: add child rule, take ownership, sets this as parent

children(self) → object¶

Returns all children rules of this rule

Returns: A list of rules

clone(self) → QgsRuleBasedLabeling.Rule¶: clone this rule, return new instance

create(ruleElem: QDomElement, context: QgsReadWriteContext) → QgsRuleBasedLabeling.Rule¶

Create a rule from an XML definition

Parameters

ruleElem – The XML rule element
context – reading context

Returns

A new rule

dependsOnScale(self) → bool¶

Determines if scale based labeling is active

Returns: True if scale based labeling is active

descendants(self) → object¶

Returns all children, grand-children, grand-grand-children, grand-gra… you get it

Returns: A list of descendant rules

description(self) → str¶

A human readable description for this rule

Returns: Description

filterExpression(self) → str¶

A filter that will check if this rule applies

Returns: An expression

findRuleByKey(self, key: str) → QgsRuleBasedLabeling.Rule¶: Try to find a rule given its unique key

insertChild(self, i: int, rule: QgsRuleBasedLabeling.Rule)¶: add child rule, take ownership, sets this as parent

isElse(self) → bool¶

Check if this rule is an ELSE rule

Returns: True if this rule is an else rule

maximumScale(self) → float¶: Returns the maximum map scale (i.e. most “zoomed in” scale) at which the label rule will be active. The scale value indicates the scale denominator, e.g. 1000.0 for a 1:1000 map. A scale of 0 indicates no maximum scale visibility.

See also

minimumScale()

See also

setMaximumScale()

New in version 3.0.

minimumScale(self) → float¶: Returns the minimum map scale (i.e. most “zoomed out” scale) at which the label rule will be active. The scale value indicates the scale denominator, e.g. 1000.0 for a 1:1000 map. A scale of 0 indicates no minimum scale visibility.

See also

maximumScale()

See also

setMinimumScale()

New in version 3.0.

parent(self) → QgsRuleBasedLabeling.Rule¶

The parent rule

Returns: Parent rule

removeChildAt(self, i: int)¶: delete child rule

requiresAdvancedEffects(self) → bool¶: Returns true if this rule or any of its children requires advanced composition effects to render.

ruleKey(self) → str¶: Unique rule identifier (for identification of rule within labeling, used as provider ID)

save(self, doc: QDomDocument, context: QgsReadWriteContext) → QDomElement¶: store labeling info to XML element

setActive(self, state: bool)¶

Sets if this rule is active

Parameters: state – Determines if the rule should be activated or deactivated

setDescription(self, description: str)¶

Set a human readable description for this rule

Parameters: description – Description

setFilterExpression(self, filterExp: str)¶

Set the expression used to check if a given feature shall be rendered with this rule

Parameters: filterExp – An expression

setIsElse(self, iselse: bool)¶

Sets if this rule is an ELSE rule

Parameters: iselse – If true, this rule is an ELSE rule

setMaximumScale(self, scale: float)¶: Sets the maximum map scale (i.e. most “zoomed in” scale) at which the rule will be active. The scale value indicates the scale denominator, e.g. 1000.0 for a 1:1000 map. A scale of 0 indicates no maximum scale visibility.

See also

maximumScale()

See also

setMinimumScale()

setMinimumScale(self, scale: float)¶: Sets the minimum map scale (i.e. most “zoomed out” scale) at which the label rule will be active. The scale value indicates the scale denominator, e.g. 1000.0 for a 1:1000 map. A scale of 0 indicates no minimum scale visibility.

See also

minimumScale()

See also

setMaximumScale()

setRuleKey(self, key: str)¶: Override the assigned rule key (should be used just internally by rule-based labeling)

setSettings(self, settings: QgsPalLayerSettings)¶: Sets new settings (or NULL). Deletes old settings if any.

settings(self) → QgsPalLayerSettings¶: Gets the labeling settings. May return a null pointer.

clone(self) → QgsRuleBasedLabeling¶

create(element: QDomElement, context: QgsReadWriteContext) → QgsRuleBasedLabeling¶: Create the instance from a DOM element with saved configuration

requiresAdvancedEffects(self) → bool¶

rootRule(self) → QgsRuleBasedLabeling.Rule¶

save(self, doc: QDomDocument, context: QgsReadWriteContext) → QDomElement¶

setSettings(self, settings: QgsPalLayerSettings, providerId: str = '')¶

Set pal settings for a specific provider (takes ownership).

Parameters

settings – Pal layer settings
providerId – The id of the provider

New in version 3.0.

settings(self, providerId: str = '') → QgsPalLayerSettings¶

subProviders(self) → List[str]¶

toSld(self, parent: QDomNode, props: Dict[str, str])¶

type(self) → str¶

writeTextSymbolizer()¶