ENVIParameterENVIGridDefinitionArray
Each ENVITask is defined by a set of parameters. Each has constraints on data type, values, etc. The ENVIParameterENVIGridDefinitionArray object is used when an ENVITask has a parameter defined as an array of type ENVIGridDefinition.
Syntax
Result = ENVIParameterENVIGridDefinitionArray( [, Properties=value])
Properties
Properties can be set as keywords to the function during creation, or retrieved using the "." notation after creation. The NAME property is required on initialization. The VALUE property is the only property that can be updated after creation.
ALLOW_NULL, DEFAULT, DESCRIPTION, DIMENSIONS, DIRECTION, DISPLAY_NAME, NAME, REQUIRED, TYPE, VALUE
Methods
Return Value
The result is a reference to a newly created object.
Properties
ALLOW_NULL
A Boolean value that indicates whether NullObject values are allowed or not. The default is 0, which causes NullObject values to fail validation. In the task template, this is defined with the allow_null key.
DEFAULT
The value returned by the VALUE property if the user does not explicitly set VALUE. The default is !NULL. The values of this property must adhere to the TYPE property. In the task template this is defined with the default key.
DIMENSIONS
The dimensions of the array, which is required on initialization. The dimensions can be specified with an array of integers or a scalar string. If the number of elements in any dimension does not matter, then use a string value of an asterisk (*) for that dimension. In the task template this is defined with the required dimensions key.
- Example of a three-element array declaration:
[3] - Example of a 1D array with any number of elements:
[*] - Example of a 2D array with any number of columns or rows:
[*, *] - Example of a 2D array with a specific number of elements:
[3, 256] - Example of a 2D array with any number of columns and three rows:
[*, 3]
DESCRIPTION
A string describing the purpose of the parameter with respect to the task. In the task template this is defined with the description key.
DIRECTION
A string that indicates whether the parameter acts as "INPUT" or "OUTPUT". The default is "INPUT". In the task template this is defined with the direction key.
DISPLAY_NAME
A string for the display name of the parameter that could be used to build a user interface. It can contain spaces and special characters. In the task template this is defined with the display_name key. If not set, the value will default to the NAME property's value.
NAME
The name of the parameter which is required on initialization. The parameter’s value can be set and retrieved from the ENVITask with the "." dot notation using this name. The name can also be used in the ENVITask::Parameter method to retrieve the parameter object. NAME must be a valid IDL variable name. In the task template this is defined with the name key. Use DISPLAY_NAME for a better user interface label.
REQUIRED
A boolean value that indicates whether the parameter is required or not. The default is 0, which allows the parameter to be optional. In the task template this is defined with the required key.
TYPE
When the type key is defined as ENVIGridDefinition in the task template, the ENVIParameterENVIGridDefinitionArray object is created and populated with the key/value pairs defined in the template. The returned TYPE property is ENVIGridDefinitionArray.
VALUE
The current value of the parameter. The parameter's VALUE can be set at any time through ENVITask using "." dot notation using the NAME of the parameter, or directly on the parameter object. The value of this property must adhere to the TYPE and DIMENSIONS property. Setting this property will internally invoke the Validate() method, and will throw an error if the new value is invalid. If you set VALUE to a scalar, it will be converted to a one-element array before being validated against the DIMENSIONS property. If you pass in an IDL List of values, they will be converted to an array during validation.
Version History
|
ENVI 5.4.1 |
Introduced |
|
ENVI 5.5 |
Added ALLOW_NULL property |
API Version
4.2