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Filter Host (FilterHostSetting)

FilterHostSetting is the reusable JSON object referenced by Filters GUID fields in receivers and activities.

It contains:

  • a list of filter conditions (Filters)
  • an optional pre-filter transformer chain (Transformers)

This page describes the JSON contract and runtime behavior only.

What it does at runtime

Execution order:

  1. Run Transformers in order (if present).
  2. Evaluate Filters as a condition expression.
  3. Mark the current activity/workflow as filtered when the condition expression evaluates to false.

Important non-obvious outcome:

  • Filter conditions are treated as pass criteria.
  • If criteria evaluate to false, the message/activity is filtered out.

JSON shape

Typical object shape:

{
  "$type": "HL7Soup.Functions.Settings.Filters.FilterHostSetting, HL7SoupWorkflow",
  "Id": "c27f2d6d-f8b5-4f0f-9fb2-7c3e0f66cb3b",
  "Name": "Primary Filters",
  "Filters": [
    {
      "$type": "HL7Soup.MessageFilters.StringMessageFilter, HL7SoupWorkflow",
      "Path": "MSH-9.2",
      "Comparer": 0,
      "Value": "A01",
      "Not": false,
      "Conjunction": 0,
      "FromSetting": "11111111-1111-1111-1111-111111111111",
      "FromType": 8,
      "FromDirection": 0
    }
  ],
  "Transformers": [],
  "Version": 3
}

Top-level fields

Field Type Required Meaning
Id GUID string yes Filter-setting identity referenced by other settings.
Name string recommended Display name for the filter set.
Filters array recommended Ordered condition/group list.
Transformers array optional Transformer actions run before filter evaluation.
Version integer optional Setting version metadata.

Filters element types

Filters is a polymorphic array. Common types:

  • HL7Soup.MessageFilters.StringMessageFilter, HL7SoupWorkflow
  • HL7Soup.MessageFilters.DateMessageFilter, HL7SoupWorkflow
  • HL7Soup.MessageFilters.ValidMessageFilter, HL7SoupWorkflow
  • HL7Soup.MessageFilters.FilterGroup, HL7SoupWorkflow

Shared fields across filter items

Field Meaning
Path Source path/text expression to evaluate.
Conjunction How this item combines with the next item (0=And, 1=Or).
Not Inverts the comparison result when true.
FromSetting Source activity/receiver GUID.
FromDirection Source side (0=inbound, 1=outbound, 2=variable).
FromType Source interpretation mode (TextWithVariables, HL7 path, XPath, CSV path, JSON path).

Optional shared-to-target fields (used by comparers that require a second operand):

Field Meaning
ToPath Second operand path/text expression.
ToSetting Second operand source setting GUID.
ToDirection Second operand source direction.
ToType Second operand interpretation type.

StringMessageFilter specific fields

Field Meaning
Comparer String comparer enum value.
Value Comparison value (or auxiliary comparer value).
CaseSensitive Case-sensitive comparison toggle.
IncludesRepeatFields Repeat-field handling hint for HL7 paths.

StringMessageFilterComparers values:

  • 0 = Equals
  • 1 = Contains
  • 2 = StartsWith
  • 3 = EndsWith
  • 4 = LengthGreaterThan
  • 5 = LengthLessThan
  • 6 = Empty
  • 7 = InMessage
  • 8 = InDataTable
  • 9 = IsTitleCase
  • 10 = IsUpperCase
  • 11 = IsLowerCase
  • 12 = InList

DateMessageFilter specific fields

Field Meaning
Comparer Date comparer enum value.
Value Date comparison value (ISO-like date string).

DateMessageFilterComparers values:

  • 0 = Equals
  • 1 = GreaterThan
  • 2 = LessThan
  • 3 = GreaterThanOrEqualTo
  • 4 = LessThanOrEqualTo
  • 5 = Empty
  • 6 = InMessage
  • 7 = InvalidDate

ValidMessageFilter specific fields

Field Meaning
Comparer Message validity comparer enum value.

ValidMessageFilterComparers values:

  • 0 = Valid
  • 1 = Invalid

FilterGroup

Group boundary marker used to structure multi-condition expressions with conjunction transitions.

Important authoring constraints:

  • Do not place FilterGroup as first or last item.
  • Do not place two FilterGroup items consecutively.

Transformers field

Transformers is the same transformer-action array contract used by TransformerSetting.

See Transformer Setting (TransformerSetting) for the full action schema.

Non-obvious outcomes

  • Empty Filters list means no filtering (message passes).
  • FilterGroup misuse (first/last/double group) can create invalid or brittle filter behavior.
  • InDataTable string comparer requires correct target data-table binding; incorrect usage can error.
  • Filter transformers run before conditions and can modify variables/message data that conditions consume.
  • FromType and FromDirection must match the source kind; mismatches produce silent no-value comparisons or failed logic.

Minimal example

{
  "$type": "HL7Soup.Functions.Settings.Filters.FilterHostSetting, HL7SoupWorkflow",
  "Id": "aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa",
  "Name": "ADT A01 Only",
  "Filters": [
    {
      "$type": "HL7Soup.MessageFilters.StringMessageFilter, HL7SoupWorkflow",
      "Path": "MSH-9.2",
      "Comparer": 0,
      "Value": "A01",
      "Conjunction": 0,
      "Not": false,
      "FromSetting": "bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb",
      "FromType": 8,
      "FromDirection": 0
    }
  ],
  "Transformers": []
}