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 (and others on the Professional Services team) for contributing this article!

Data Model Expressions

Default Value Expressions

Current date

• Now

New Guid (Globally Unique IDentifier)

• Guid.NewGuid

Inspecting portions of link path for original file (path, filename, metadata) attached to a Batch Folder

• These examples extract information (full path & filename, filename, path, extension) from a Batch Folder's content link
  • Link.FullPath
    • Returns the attached file's path, including the file's name.
  • Link.Path
    • Returns the attached file's path, not including the file's name.
  • Link.ObjectName
    • Returns the attached file's name.
  • Link.LinkName
    • Returns the name of the link (e.g. "Import" or "Export")
  • IO.Path.GetFileNameWithoutExtension(Link.ObjectName)
    • Returns the attached file's name without the extension.
  • IO.Path.GetExtension(Link.ObjectName)
• These examples extract specific path segments (drive letter, first folder name) from a batch folder's content link
  • Link.PathSegments(0)
    • Returns the first segment of the file path (e.g. "C:" in "C:\Documents\Howdy.pdf").
  • Link.PathSegments(1)
    • Returns the second segment of the file path (e.g. "Documents" in "C:\Documents\Howdy.pdf").

Note: If you have removed the document link with the Execute > Remove Link command, you can still access the attached file's name using the expression Folder.AttachmentFileName

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

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

Populating fields with the name of the document's classified Document Type

• ContentTypeName
• Note: This is a shortcut for the expression Folder.ContentType.DisplayName

Populating fields with the name of the document's classified Document Type's Content Category.

• Folder.ContentType.ParentNode.DisplayName
• Note: When using Content Categories, Document Types are added as child nodes to the Content Category object in the node tree. So, this expression first uses Folder to select the document folder in the Batch. Then, ContentType inspects the document's classified Document Type. The Document Type is a child of the Content Category in this example. Since the Content Category is the Document Type's parent object, the ParentNode jumps up the node tree hierarchy to inspect the parent Content Category. Last, DisplayName returns the Content Category's name.

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)

Getting the location coordinates of a field on the document

• This could be used to determine the coordinates and size of an extracted value on a document.
  • GetFieldInstance("Field Name").Location.ToString
  • Note, this returns logical location in inches, not pixels. So additional work would need to be performed to convert this to pixels if needed.

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

• DirectCast(Item, BatchFolder).ContentTypeName = "Document Type Name"

Functions and Should Submits

Grooper can now use lambda functions in expressions (and not just Should Submits, all expressions!). This gives you some really advanced capabilities if you have more advanced .NET programing skills.

This example determines if a page scoped task, like Recognize or Execute > Rasterize should be submitted depending on how many text segments are present on a PDF page. If the PDF page has less than 15 text segments, the tasks submits, otherwise the PDF page is not processed.

• This is useful when dealing with poorly formed PDFs that must be forced to be treated like an image when Grooper otherwise thinks they are a native text document.

Function() As Boolean
  If DirectCast(Item, BatchPage).IsPDF
    Dim doc As Grooper.PDF.PdfDoc = New Grooper.PDF.PdfDoc(DirectCast(Item, BatchPage).GetImageVersion, True)
    Dim info As Grooper.PDF.PdfPageInfo = doc.Sharp.GetPageInfo(0)
    Return (info.DrawTextOps.Count < 15)
  End If
  
End Function

You could change what property values determine if the task is submitted by changing the Return statement in the function. Here are some examples:

• Return info.PageType = PDF.PdfPageInfo.PageTypes.Mixed - Tasks would submit if the PDF's page type is "Mixed"
• Return info.RenderResolution = "Color @ 300 DPI" - Tasks would submit if the PDF's render format is Color @ 300 DPI.
• Return info.PageSize = "8.50"" x 11.00""" - Tasks would submit if the PDF's page size is 8.5 x 11.
• Return info.Images.Count = "4" - Tasks would submit if PDF has exactly 4 images embedded in it.
• Return info.PathSegments.Count > "257" - Tasks would submit if the PDF has more than 257 vector drawing paths.

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.VerticalLines.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)

Converting a date field to a string in a "year-month-day" format

• DateField.ToString("yyyy-MM-dd")

Misc Expression Snippets

These expressions may or may not be useful by themselves. It's most likely they are used as part of a larger expression. They are documented here to keep track of previously requested solutions.

Count the number of children at a certain level. This would count the number of Batch Folders that are direct children of a Batch Folder being processed.

• ChildrenAtLevel(1).Count

Count the number of children at a certain level of a parent folder. This would count the number of Batch Folders that are direct children of the parent Batch Folder relative to the Batch Folder being processed.

• ParentFolder.ChildrenAtLevel(1).Count

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)