24.1.6. Modeler tools

These tools are only available in the Graphical Modeler. They are not available in the Processing Toolbox.

24.1.6.1. Conditional branch

Adds a conditional branch into a model, allowing parts of the model to be executed based on the result of an expression evaluation. Mostly by using tool dependencies to control the flow of a model.

Parameters

Label

名称

Type

Description

Field

BRANCH

[string]

Name of the condition

Field

CONDITION

[expression]

Expression to evaluate

Outputs

None.

Python code

Algorithm ID: native:condition

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Using processing algorithms from the console for details on how to run processing algorithms from the Python console.

24.1.6.2. Load layer into project

Loads a layer to the current project.

Parameters

Label

名称

Type

Description

Layer

INPUT

[layer]

Layer to load in the legend

Loaded layer name

NAME

[string]

Name of the loaded layer

Outputs

Label

名称

Type

Description

Layer

OUTPUT

[same as input]

The (renamed) loaded layer

Python code

Algorithm ID: qgis:loadlayer

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Using processing algorithms from the console for details on how to run processing algorithms from the Python console.

24.1.6.3. Raise exception

Raises an exception and cancels a model's execution. The exception message can be customized, and optionally an expression based condition can be specified. If an expression condition is used, then the exception will only be raised if the expression result is true. A false result indicates that no exception will be raised, and the model execution can continue uninterrupted.

Parameters

Label

名称

Type

Description

Message

MESSAGE

[string]

Message to display

Condition

CONDITION

[expression]

Expression to evaluate if true

Outputs

None.

Python code

Algorithm ID: native:raiseexception

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Using processing algorithms from the console for details on how to run processing algorithms from the Python console.

24.1.6.4. Raise warning

Raises a warning message in the log. The warning message can be customized, and optionally an expression based condition can be specified. If an expression condition is used, then the warning will only be logged if the expression result is true. A false result indicates that no warning will be logged.

Parameters

Label

名称

Type

Description

Message

MESSAGE

[string]

Message to display

Condition

CONDITION

[expression]

Expression to evaluate if true

Outputs

None.

Python code

Algorithm ID: native:raisewarning

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Using processing algorithms from the console for details on how to run processing algorithms from the Python console.

24.1.6.5. Rename layer

Renames a layer.

Parameters

Label

名称

Type

Description

Layer

INPUT

[layer]

Layer to rename

New name

NAME

[string]

The new name of the layer

Outputs

Label

名称

Type

Description

Layer

OUTPUT

[same as input]

The (renamed) output layer

Python code

Algorithm ID: native:renamelayer

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Using processing algorithms from the console for details on how to run processing algorithms from the Python console.

24.1.6.6. Save log to file

Saves the model's execution log to a file. Optionally, the log can be saved in a HTML formatted version.

Parameters

Label

名称

Type

Description

Use HTML

USE_HTML

[Boolean]

Default: False

Use HTML formatting

Outputs

Label

名称

Type

Description

File

OUTPUT

[string]

Destination of the log

Python code

Algorithm ID: native:savelog

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Using processing algorithms from the console for details on how to run processing algorithms from the Python console.

24.1.6.7. Set project variable

Sets an expression variable for the current project.

Parameters

Label

名称

Type

Description

Variable name

NAME

[string]

Name of the variable

Variable value

VALUE

[string]

Value to be stored

Outputs

None.

Python code

Algorithm ID: native:setprojectvariable

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Using processing algorithms from the console for details on how to run processing algorithms from the Python console.

24.1.6.8. String concatenation

Concatenates two strings into a single one in the Processing Modeler.

Parameters

Label

名称

Type

Description

Input 1

INPUT_1

[string]

First string

Input 2

INPUT_2

[string]

Second string

Outputs

Label

名称

Type

Description

Concatenation

CONCATENATION

[string]

The concatenated string

Python code

Algorithm ID: qgis:stringconcatenation

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Using processing algorithms from the console for details on how to run processing algorithms from the Python console.