Expressions Cookbook (Concept)

Expressions are snippets of .NET code, allowing Grooper to do various things outside its "normal" parameters. This includes calculating or validating extracted Data Field values in a Data Model, applying conditional execution of a Batch Process or IP Profile, and more! This article collects examples of common (and maybe not so common) uses of expressions in Grooper.

😎	Special thanks to BIS team member Brian Godwin for contributing this article!

Data Model Expressions

Default Value Expressions

Current date

• Now

Inspecting portions of link path for original file (path, filename, metadata)

• These examples extract information (full path & filename, filename, path, extension) from a batch folder's content link
  • Link.FullPath
  • Link.Name
  • Link.Path
  • IO.Path.GetFileNameWithoutExtension(Link.Name)
  • IO.Path.GetExtension(Link.Name)
• These examples extract specific path segments (drive letter, first folder name) from a batch folder's content link
  • Link.PathSegments(0)
  • Link.PathSegments(1)

Populating fields with specific values (i.e. strings, numbers, dates)

• "Hello world!"
• 123.45
• DateAdd("d", 30, Now)
• Now.ToString("yyyyMMddhhmmss")

Calculate Expressions

Addition of multiple fields

• IntegerField1 + IntegerField2
• DecimalField1 + DecimalField2 + DecimalField3

Concatenation of multiple fields

• String.Concat(StringField1, StringField2)
• String.Concat(StringField1, StringField2, StringField3)
• String.Concat(StringField1, StringField2, StringField3, StringField4)

Rounding

• This example rounds a decimal value to a precision of 4 digits (e.g. 2.34567891 to 2.3457)
  • Math.Round(DecimalField1, 4)

Non-integer addition (e.g. of date values)

• These examples increment a date by 30 days ("d"), 1 year ("yyyy"), and the last decrements the date by 3 months ("m")
  • DateAdd("d", 30, DateField1)
  • DateAdd("yyyy", 1, DateField1)
  • DateAdd("m", -3, DateField1)

Reformatting / Normalization of values

• This example replaces any backslashes with underscores
  • StringField1.Replace("\", "_")
• This example removes any backslashes
  • StringField1.Replace("\", "")

Substring calculation

• These examples extract information contained within a string "ABC123456XXXX654321YYY" by designating the 0-based starting index and desired number of characters
  • ABC (first 3 characters): StringField1.Substring(0, 3)
  • 123456 (6 characters within the string): StringField1.Substring(3, 6)
  • XXXX (4 characters within the string): StringField1.Substring(9, 4)
  • YYY (last 3 characters): StringField1.Substring(StringField1.Length - 3)

Validate Expressions

Date in past / future

• This example ensures the date value is a past date
  • DateField1 < Now
• This example ensures the date value is at least 30 days in the future
  • DateField1 >= DateAdd("d", 30, Now)

Equality / inequality of two fields (multiple options)

• StringField1 = StringField2
• IntegerField1.Equals(IntegerField2)
• IntegerField1 <> DecimalField1
• Not DecimalField1.Equals(DecimalField2)

Summing fields and comparing to another field

• IntegerField1 + IntegerField2 = IntegerField3
• DecimalField1 + DecimalField2 = DecimalField3
• DecimalField1 = SumFieldInstance("Table1\AmountColumn")

Running regular expression against field

• Text.RegularExpressions.Regex.IsMatch(StringField1, "[0-9]{6}")

Inspecting field-level confidence scores

• Instance.Confidence > 0.8

Batch Processing Expressions

Should Submit Expression

Inspecting flagged status

• These examples would submit the task when the object (i.e. folder, page) is flagged or not flagged (2nd example)
  • Item.Flagged
  • Not Item.Flagged
• This example would submit the task when the object (folder) contains one or more flagged pages
  • DirectCast(Item, BatchFolder).FlaggedPages.Any()

Inspecting flagged message

• Item.FlagReason = "Needs classification"
• Item.FlagReason <> "Bypass review"

Inspecting presence of local copy in Grooper

• DirectCast(Item, BatchFolder).HasLocalCopy

Inspecting existence of native version

• DirectCast(Item, BatchFolder).HasAttachment

Inspecting MIME type

• This example would submit the task when the object's (folder) represents a native PDF or the second if its mime type is PDF
  • DirectCast(Item, BatchFolder).IsNativePDF
  • DirectCast(Item, BatchFolder).AttachmentMimeType = "application/pdf"

Inspecting content type / parent content category

• DirectCast(Item, BatchFolder).ContentTypeName = "MyContentType"
• DirectCast(DirectCast(Item, BatchFolder).ContentType.ParentNode, ContentCategory).Name = "MyContentCategory"

Inspecting if a field is blank / populated

• DirectCast(Item, BatchFolder).IndexData.Fields("StringField1").Value <> ""
• Not String.IsNullOrEmpty(DirectCast(Item, BatchFolder).IndexData.Fields("StringField1").Value)

Inspecting image properties (resolution, color mode, aspect ratio, size (in bytes), pixel count, etc.)

• DirectCast(Item, BatchPage).PrimaryImage.ResolutionX < 240
• DirectCast(Item, BatchPage).PrimaryImage.IsBinary
• DirectCast(Item, BatchPage).PrimaryImage.IsColor
• DirectCast(Item, BatchPage).PrimaryImage.IsLandscape
• DirectCast(Item, BatchPage).PrimaryImage.AspectRatio > 1.25
• DirectCast(Item, BatchPage).PrimaryImage.Size > 40960
• DirectCast(Item, BatchPage).PrimaryImage.PixelCount > 3500000

Inspecting presence of layout data (of a certain type: lines, OMR boxes, etc.)

• DirectCast(Item, BatchFolder).HasLayoutData

Does page / document have OCR text?

• DirectCast(Item, BatchFolder).HasRuntimeOCR
• DirectCast(Item, BatchPage).HasRuntimeOCR

Inspecting classification candidates and classification scores, incl. alternate candidate scores

Next Step Expressions

Inspecting batch creator

• If(Batch.CreatedBy.ToLower() = "domain\jusername", TrueStepName, FalseStepName)
• If(Batch.CreatedByDisplayName = "Joe Username", TrueStepName, FalseStepName)

Inspecting creation time (range, day of week)

• If(DatePart(DateInterval.Month, Batch.Created) = 6, TrueStepName, FalseStepName)
• If(DatePart(DateInterval.Day, Batch.Created) > 15, TrueStepName, FalseStepName)

IP Profile Expressions

IP Command Should Execute Expressions

Inspecting image properties (resolution, color mode, aspect ratio, size, pixel count, etc.)

• Image.ResolutionX < 240
• Image.IsBinary
• Image.IsColor
• Image.IsLandscape
• Image.AspectRatio > 1.25
• Image.Size > 40960
• Image.PixelCount > 3500000

Inspecting presence of layout data (of a certain type: lines, OMR boxes, etc.)

• Results.Line_Detection.HorizontalLines.Any()
• Results.Line_Detection.VerticallLines.Any()
• Results.Box_Detection.Boxes.Any()
• Results.Patch_Code_Detection.PatchCodes.Any()

Decisioning based on image classification (Results.ClassifyImage.whatever)

• Results.Classify_Image.ClassName = "Sample 1"

Accessing and inspecting results log of prior IP commands

• Results.Measure_Entropy.Entropy > 0.85

Inspecting whether prior commands modified image(s)

• ResultList.IsImageSourceImage

Mapping Expressions

Import Mapping Expressions

Value concatenation

• String.Concat(field1, field2)
• String.Concat(field1, " ", field2)

Value padding (adding or removing)

• These examples show how to left-pad a value with zeroes for 20 characters, right-pad a value with spaces for 40 characters, and finally trim a padded value of spaces.
  • field1.PadLeft(20, "0"c)
  • field2.PadRight(40)
  • field3.Trim()

Adding environment variables (date, user, etc.)

• Now
• Environment.MachineName
• Environment.UserName
• Environment.UserDomainName
• Environment.OSVersion
• Environment.ProcessorCount

Export Mapping Expressions

Addition of multiple fields

• IntegerField1 + IntegerField2
• DecimalField1 + DecimalField2 + DecimalField3

Concatenation of multiple fields

• String.Concat(StringField1, StringField2)
• String.Concat(StringField2, ", ", StringField1, ": ", StringField3)

How to access Grooper attributes (content type name, GUID, index data, etc.)

• CurrentDocument.ContentTypeName
• CurrentDocument.Id
• CurrentDocument.IndexData.Sections("Section1").Fields("Field1").Value
• CurrentDocument.IndexData.Sections("Section1").Sections("SectionA").Fields("Field1A").Value
• CurrentDocument.IndexData.Tables("Table1").Rows.First().Cells("Column1").Value

Naming based on original file name

• IO.Path.GetFileNameWithoutExtension(CurrentDocument.ContentLink.Name)

General

WIP	This section is a work-in-progress. It needs to be expanded for completeness.

Understanding how to traverse hierarchy of, e.g. batch or content model

Understanding how to parse tables by row & column

Identifying Sections by instance number

How to inspect properties of node

Dynamic referencing vs. GUID referencing

Conditional expressions with IIF / IF

Using LINQ in Expressions

• LINQ to Grooper Objects

Direct Casting: when to (Cast)