Namespace Strategy

The XAML namespace block is not static — it is constructed at workflow assembly time based on the activities present in the spec.

Feature Detection Pass

Before any XAML is emitted, generate_workflow walks the entire activity tree and sets boolean flags:

all_gen_names = {a.get("gen") for a in _walk_all_activities(activities)}

has_ui          = all_gen_names ∩ ui_gens         # nclick, ntypeinto, napplicationcard_*, ...
has_datatable   = DataTable/DataRow in args/vars
                  OR {foreach_row, nextractdata} in spec
has_securestring= SecureString in any arg/variable type
has_http        = "net_http_request" in spec

Plugin generators also contribute: if a plugin gen name appears in the spec, its registered namespace is included.

The sd: Prefix Collision

sd: is the conflict point. Studio uses it for two different namespaces depending on context:

• UI-only workflows: sd = System.Drawing (needed by NApplicationCard's OCR engine blocks)
• Non-UI workflows: sd = System.Data (needed by DataTable variables and activities)

When a workflow has both UI activities and DataTable, both namespaces are needed simultaneously — but they cannot share the same prefix. This is the "Option B" strategy in _build_namespaces:

Workflow content	sd: assignment	Extra prefixes
UI only	System.Drawing	sd1: = Drawing.Primitives
Non-UI	System.Data	—
UI + DataTable	System.Data	sdd: = Drawing, sdd1: = Drawing.Primitives

Post-Processing Remapping

Generators always emit Drawing types with sd: (e.g., sd:Image, sd1:Rectangle) and DataTable types with sd2: (e.g., sd2:DataTable), regardless of which namespace strategy applies. After the full XAML body is assembled, a post-processing pass remaps the prefixes:

if has_ui and has_datatable:
    body = (body
        .replace("sd2:DataTable", "sd:DataTable")
        .replace("sd:Image",      "sdd:Image")
        .replace("sd1:Rectangle", "sdd1:Rectangle")
    )

This string replacement on generated output is a known fragility — see Friction: Structural Knowledge in F-Strings.

Conditional Namespace Prefixes

Prefix	Condition	URI / CLR namespace
ss:	has_securestring	System.Security
uix:	has_ui	http://schemas.uipath.com/workflow/activities/uix
uwah:	has_http	UiPath.Web.Activities.Http
uwahm:	has_http	UiPath.Web.Activities.Http.Models
plugin prefixes	plugin gen in spec	registered by register_namespace()

Always-Present Prefixes

These appear in every generated workflow regardless of content:

x:, s:, sap:, sap2010:, scg:, sco:, ui:, mc:, default namespace