RQGIS (version 0.2.0)

get_args_man: Get GIS arguments and respective default values

Description

get_args_man retrieves automatically function arguments and respective default values for a given QGIS geoalgorithm.

Usage

get_args_man(alg = NULL, options = FALSE, qgis_env = set_env())

Arguments

alg

The name of the algorithm for which one wishes to retrieve arguments and default values.

options

Sometimes one can choose between various options for a function argument. Setting option to TRUE will automatically assume one wishes to use the first option (default: FALSE).

qgis_env

Environment containing all the paths to run the QGIS API. For more information, refer to set_env.

Value

The function returns a list whose names correspond to the function arguments one needs to specify. The list elements correspond to the argument specifications. The specified function arguments can serve as input for run_qgis's params argument. Please note that although get_args_man tries to retrieve default values, one still needs to specify some function arguments manually such as the input and the output layer.

Details

get_args_man basically mimics the behavior of the QGIS GUI. That means, for a given GIS algorithm, it captures automatically all arguments and default values. In the case that a function argument has several options, one can indicate to use the first option (see also get_options), which is the QGIS GUI default behavior.

Examples

# NOT RUN {
get_args_man(alg = "qgis:addfieldtoattributestable")
# and using the option argument
get_args_man(alg = "qgis:addfieldtoattributestable", options = TRUE)
# }