Class: QgsRuleBasedLabeling¶

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

Bases: QgsAbstractVectorLayerLabeling

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

New in version 3.0.

Parameters: root –

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.

Parameters

settings (QgsPalLayerSettings) –
maximumScale (float = 0) –
minimumScale (float = 0) –
filterExp (str = '') –
description (str = '') –
elseRule (bool = False) –

Filtered = 0¶

Inactive = 1¶

class RegisterResult¶: Bases: int

Registered = 2¶

active(self) → bool¶

Returns if this rule is active

Return type: bool
Returns: True if the rule is active

appendChild(self, rule: QgsRuleBasedLabeling.Rule)¶

add child rule, take ownership, sets this as parent

Parameters: rule (QgsRuleBasedLabeling.Rule) –

children(self) → object¶

Returns all children rules of this rule

Return type: object
Returns: A list of rules

clone(self) → QgsRuleBasedLabeling.Rule¶

clone this rule, return new instance

Return type: QgsRuleBasedLabeling.Rule

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

Create a rule from an XML definition

Parameters

ruleElem (QDomElement) – The XML rule element
context (QgsReadWriteContext) – reading context

Return type

QgsRuleBasedLabeling.Rule

Returns

A new rule

dependsOnScale(self) → bool¶

Determines if scale based labeling is active

Return type: bool
Returns: True if scale based labeling is active

descendants(self) → object¶

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

Return type: object
Returns: A list of descendant rules

description(self) → str¶

A human readable description for this rule

Return type: str
Returns: Description

filterExpression(self) → str¶

A filter that will check if this rule applies

Return type: str
Returns: An expression

findRuleByKey(self, key: str) → QgsRuleBasedLabeling.Rule¶

Try to find a rule given its unique key

Parameters: key (str) –
Return type: QgsRuleBasedLabeling.Rule

insertChild(self, i: int, rule: QgsRuleBasedLabeling.Rule)¶

add child rule, take ownership, sets this as parent

Parameters

i (int) –
rule (QgsRuleBasedLabeling.Rule) –

isElse(self) → bool¶

Check if this rule is an ELSE rule

Return type: bool
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.

Return type: float

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.

Return type: float

parent(self) → QgsRuleBasedLabeling.Rule¶

The parent rule

Return type: QgsRuleBasedLabeling.Rule
Returns: Parent rule

removeChildAt(self, i: int)¶

delete child rule

Parameters: i (int) –

requiresAdvancedEffects(self) → bool¶

Returns true if this rule or any of its children requires advanced composition effects to render.

Return type: bool

ruleKey(self) → str¶

Unique rule identifier (for identification of rule within labeling, used as provider ID)

Return type: str

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

store labeling info to XML element

Parameters

doc (QDomDocument) –
context (QgsReadWriteContext) –

Return type

QDomElement

setActive(self, state: bool)¶

Sets if this rule is active

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

setDescription(self, description: str)¶

Set a human readable description for this rule

Parameters: description (str) – Description

setFilterExpression(self, filterExp: str)¶

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

Parameters: filterExp (str) – An expression

setIsElse(self, iselse: bool)¶

Sets if this rule is an ELSE rule

Parameters: iselse (bool) – 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()

Parameters: scale (float) –

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()

Parameters: scale (float) –

setRuleKey(self, key: str)¶

Override the assigned rule key (should be used just internally by rule-based labeling)

Parameters: key (str) –

setSettings(self, settings: QgsPalLayerSettings)¶

Sets new settings (or NULL). Deletes old settings if any.

Parameters: settings (QgsPalLayerSettings) –

settings(self) → QgsPalLayerSettings¶

Gets the labeling settings. May return a null pointer.

Return type: QgsPalLayerSettings

clone(self) → QgsRuleBasedLabeling¶

Return type: QgsRuleBasedLabeling

create(element: QDomElement, context: QgsReadWriteContext) → QgsRuleBasedLabeling¶

Create the instance from a DOM element with saved configuration

Parameters

element (QDomElement) –
context (QgsReadWriteContext) –

Return type

QgsRuleBasedLabeling

requiresAdvancedEffects(self) → bool¶

Return type: bool

rootRule(self) → QgsRuleBasedLabeling.Rule¶

Return type: QgsRuleBasedLabeling.Rule

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

Parameters

doc (QDomDocument) –
context (QgsReadWriteContext) –

Return type

QDomElement

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

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

Parameters

settings (QgsPalLayerSettings) – Pal layer settings
providerId (str = '') – The id of the provider

New in version 3.0.

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

Parameters: providerId (str = '') –
Return type: QgsPalLayerSettings

subProviders(self) → List[str]¶

Return type: List[str]

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

Parameters

parent (QDomNode) –
props (Dict[str) –

type(self) → str¶

Return type: str

writeTextSymbolizer()¶