Example of VisTrails API usage (planned)

vtapi.py

import vistrails.api as vt


# No initialization, no application creation


# Opens a vistrail
# Vistrail wraps the Vistrail and VistrailController
vistrail = vt.load_vistrail("terminator.vt")
assert isinstance(vistrail, vt.Vistrail)


# We can get pipelines from the vistrail
pipeline = vistrail.get_pipeline(3)
pipeline = vistrail.get_pipeline("some_tag")
assert isinstance(vistrail, vt.Pipeline)

# or change the "current" one, from which new versions are derived
vistrail.set_current_pipeline("some_tag")
assert isinstance(vistrail.current_pipeline, vt.Pipeline)


# Wrappers should do sanity checks and raise exceptions for problems (don't
# show popups...)
try:
    vistrail.get_pipeline(object())
except TypeError:
    pass
try:
    vistrail.get_pipeline(108)
except vt.NoSuchVersion:
    pass


# Loading packages should be done when requested, NOT from the configuration
# file. It should not update the user's preferences either...
urlpkg = vt.load_package("org.vistrails.vistrails.url")
assert isinstance(urlpkg, vt.Package)
try:
    vt.load_package("org.vistrails.nonexistent.nonexistentpkg")
except vt.NoSuchPackage:
    pass


# Alias for basic_modules? This is probably a good idea
bmods = vt.basic_modules


# Easy execution of a (sub)workflow as a Python function (requested by Claudio)
bound = vistrail.current_pipeline.get_module("higher_bound")  # InputPort module
target = vistrail.current_pipeline.get_module("target_file")
sinkmodule = vistrail.current_pipeline.get_module("passes")
vistrail.execute(
    sinkmodule,  # "run this module" function: run part of a pipeline
    bound == vt.Function(bmods.Integer, 10),  # explicit typing
    target == "/tmp/vt_output")  # implicit typing (if 'target' is a File...)
results = vistrail.execute(higher_bound=10, target_file="/tmp/vt_output)

assert isinstance(results, vt.Results)
print results.output_port['passes'] - 1  # value passed to OutputPort module
results.module(4).outputs['value']  # access to ports of executed modules


# OutputModules support?
with vt.output_mode('ImageOutput', 'file',
                    directory='/tmp/', prefix='apitest_image', format='png'):
    pipeline.execute()


# IPython support
vistrail.get_pipeline('ipython_test').execute()
# <visualization embedded in qtconsole / notebook>


# Workflow changes? (create new versions, change current vistrail)
# (similarities with ORMs here...)
mod = visturlpkg.DownloadFile(url="http://www.vistrails.org/skins/vistrails/vistrails_logo.png")
vistrail.add_module(mod)  # single version created, that adds module with 'url' function set

mod.url = "http://www.google.com/"
mod.insecure = True
bound.name = 'high_bound'
vistrail.add_modules([mod, bound], desc="Params 2.0")  # single version created, that sets 3 parameters
vistrail.tag("Revised version")

vistrail.save("/tmp/new_terminator.vt")