Process components (`[PROCESS_COMPONENTS]`)#

Note

Engine: OpenSWMM 6 — refactored.

solver.process_components enumerates and edits the [PROCESS_COMPONENTS] registrations — the file-binding surface that tells the engine which optional process components (heat, water age, reactions, …) are active and where each one’s config file lives.

Reference: openswmm_process_components.h.

Quickstart#

from openswmm.engine import Solver

with Solver("model.inp") as s:
    for c in s.process_components:
        print(c.component_index, c.id, c.config, c.resolved)

    "heat" in s.process_components          # membership by id
    s.process_components["heat"].config     # config="…" as written

    # Register first, then write the file it points at.
    s.process_components.register("waterage", "model.age")
    open("model.age", "w").write("[WATER_AGE_SOURCES]\n")

    s.process_components.remove("waterage")

Warning

register and remove are BUILDING/OPENED only.

The registration record#

Each entry is a ProcessComponent named tuple.

Field	Meaning
`component_index`	Position in the section, `0 .. len-1`.
`id`	Component id, e.g. `"heat"`.
`config`	The `config="…"` argument exactly as written. May be `""` when the registration named no file.
`resolved`	The effective path the config was actually read from at the last open.

Important

resolved is "" until the last open resolved it. An empty resolved therefore means “not resolved yet”, not “no file” — check config to tell the two apart. On a model built programmatically and never opened, every resolved is empty.

Enumerating and finding#

Operation	Behaviour
`len(s.process_components)`	Number of registrations.
`s.process_components[key]`	One `ProcessComponent` by `int` index or `str` id.
`for c in s.process_components:`	Iterate in section order.
`"heat" in s.process_components`	Membership test on the component id.
`.get_index(component_id)`	Registration index for an id.
`.register(component_id, config_path="")`	Add a registration; returns the new `ProcessComponent`.
`.remove(key)`	Delete by index or id.

Registering before the file exists#

The “create a component and its config file” flow registers first, then writes the file. A config_path that does not exist yet is legal: the path is stored as written, and resolution happens at the next open.

c = s.process_components.register("reactions", "chlorine.rxn")
assert c.resolved == ""              # nothing resolved it yet
s.reactions.save("chlorine.rxn")     # now the file exists

Warning

A duplicate id is refused. Check with in or ProcessComponents.get_index() before registering, rather than relying on a retry.
ProcessComponents.remove() shifts the indices of every later registration. Cached component_index values go stale — re-enumerate, or address components by id.

Built-in registry#

solver.process_components.known() returns immutable registry entries with id, description and implemented fields. The registry describes the build’s vocabulary; it differs from the components configured on a model. Entries with implemented=False are placeholders and cannot supply a process implementation merely by being registered in the model.

Process components ([PROCESS_COMPONENTS])#