Declarative Workflows

Once you have your collection of Routines, you can describe the workflow itself with a yaml file.

The YAML file

The yaml file is a collection of descriptions of your routines. There are three important aspects of a routine description:

1. The label. Other routines will refer to it by this label.
2. The data property. Specifies from which other routine it gets the data it acts on.
3. The other properties. They will be passed as constructor arguments to the properties.

The Label

The label must simply be a valid json label. Alpha-numeric plus underscores, starting with a letter.

The Data Property

The data property has one required sub-property, from. from can name another routine in the yaml workflow, or an external routine. External routines are detected by the presence of a dot (.) in the value.

Aditional sub-properties are allowed on data. They will be passed as arguments when the data is accessed. For example, a routine which filters the data might take a boolean argument when accessed, to toggle whether to provide rows which were matched or unmatched.

For from properties containg ., the following strategy is used to try and access the routine:

1. Look for a .yaml files in the current directory with a name matching the label preceding the last ., with a routine matching the label following the last ..
2. Try to import a module using the the part of the label preceding the last ., with an importable object matching the label following the last ..

Additional Properties

Any additional properties will tell the routine about itself when created.

Running a Workflow

Run the whole thing: timeflow workflow.yaml

Run a routine (and all its dependencies): timeflow workflow.yaml routine

Specifiy what sort of output you want: timeflow workflow -o csv

• The label after the -o file will first try to use a builtin timeflow, or try to import an export routine if it contains a dot.