The default value for this parameter to use if either there is no
source field, or the value produced by the source is null. The
default must be applied prior to scattering or evaluating valueFrom.
The unique identifier for this object.
A short, human-readable label of this object.
The method to use to merge multiple inbound links into a single array. If not specified, the default method is "merge_nested".
Only valid when type: File or is an array of items: File.
If true, the file (or each file in the array) must be a UTF-8
text file 64 KiB or smaller, and the implementation must read
the entire contents of the file (or file array) and place it
in the contents field of the File object for use by
expressions. If the size of the file is greater than 64 KiB,
the implementation must raise a fatal error.
Only valid when type: Directory or is an array of items: Directory.
Specify the desired behavior for loading the listing field of
a Directory object for use by expressions.
The order of precedence for loadListing is:
loadListing on an individual parameterLoadListingRequirementno_listingThe method to use to choose non-null elements among multiple sources.
Specifies one or more workflow parameters that will provide input to the underlying step parameter.
To use valueFrom, StepInputExpressionRequirement must be specified in the workflow or workflow step requirements.
If valueFrom is a constant string value, use this as the value for
this input parameter.
If valueFrom is a parameter reference or expression, it must be
evaluated to yield the actual value to be assiged to the input field.
The self value in the parameter reference or expression must be
null if there is no source fieldsource field when this
workflow input parameter is not specified in this workflow step's scatter field.source field when this workflow input
parameter is specified in this workflow step's scatter field.The value of inputs in the parameter reference or expression must be
the input object to the workflow step after assigning the source
values, applying default, and then scattering. The order of
evaluating valueFrom among step input parameters is undefined and the
result of evaluating valueFrom on a parameter must not be visible to
evaluation of valueFrom on other parameters.
Generated using TypeDoc
Auto-generated interface for https://w3id.org/cwl/cwl#WorkflowStepInput
The input of a workflow step connects an upstream parameter (from the workflow inputs, or the outputs of other workflows steps) with the input parameters of the process specified by the
runfield. Only input parameters declared by the target process will be passed through at runtime to the process though additonal parameters may be specified (for use withinvalueFromexpressions for instance) - unconnected or unused parameters do not represent an error condition.Input object
A WorkflowStepInput object must contain an
idfield in the form#fieldnameor#prefix/fieldname. When theidfield contains a slash/the field name consists of the characters following the final slash (the prefix portion may contain one or more slashes to indicate scope). This defines a field of the workflow step input object with the value of thesourceparameter(s).Merging multiple inbound data links
To merge multiple inbound data links, MultipleInputFeatureRequirement must be specified in the workflow or workflow step requirements.
If the sink parameter is an array, or named in a workflow scatter operation, there may be multiple inbound data links listed in the
sourcefield. The values from the input links are merged depending on the method specified in thelinkMergefield. If bothlinkMergeandpickValueare null or not specified, and there is more than one element in thesourcearray, the default method is "merge_nested".If both
linkMergeandpickValueare null or not specified, and there is only a single element in thesource, then the input parameter takes the scalar value from the single input link (it is not wrapped in a single-list).merge_nested
The input must be an array consisting of exactly one entry for each input link. If "merge_nested" is specified with a single link, the value from the link must be wrapped in a single-item list.
merge_flattened
Picking non-null values among inbound data links
If present,
pickValuespecifies how to picking non-null values among inbound data links.pickValueis evaluatedlinkMerge.scatterorvalueFrom.This is specifically intended to be useful in combination with conditional execution, where several upstream steps may be connected to a single input (
sourceis a list), and skipped steps produce null values.Static type checkers should check for type consistency after infering what the type will be after
pickValueis applied, just as they do currently forlinkMerge.first_non_null
For the first level of a list input, pick the first non-null element. The result is a scalar. It is an error if there is no non-null element. Examples:
[null, x, null, y] -> x[null, [null], null, y] -> [null][null, null, null] -> Runtime ErrorIntended use case: If-else pattern where the value comes either from a conditional step or from a default or fallback value. The conditional step(s) should be placed first in the list.
the_only_non_null
For the first level of a list input, pick the single non-null element. The result is a scalar. It is an error if there is more than one non-null element. Examples:
[null, x, null] -> x[null, x, null, y] -> Runtime Error[null, [null], null] -> [null][null, null, null] -> Runtime ErrorIntended use case: Switch type patterns where developer considers more than one active code path as a workflow error (possibly indicating an error in writing
whencondition expressions).all_non_null
For the first level of a list input, pick all non-null values. The result is a list, which may be empty. Examples:
[null, x, null] -> [x][x, null, y] -> [x, y][null, [x], [null]] -> [[x], [null]][null, null, null] -> []Intended use case: It is valid to have more than one source, but sources are conditional, so null sources (from skipped steps) should be filtered out.