Need to increment the serial number in a editable grid when a new row is added

Hello,

From: https://docs.appian.com/suite/help/20.1/recipe-add-edit-and-remove-data-in-an-inline-editable-grid.html

you have an example. For counting, you just need a length function to see how many items you have in your array.

a!localVariables(
  /*  
  * local!employess is provided in this recipe as a way to start with hard-coded
  * data. However, this data is identical to the data created from the entity-backed
  * tutorial. Replace the hard-coded data with a query to the employee data store
  * entity and all of the employee records from the tutorial will appear.
  *
  * To replace this data with your own, replace (ctrl+H or cmd+H) all references to
  * local!employees with your data source, either via rule input or local variable.
  */
  local!employees: {
    { id: 1, firstName: "John" , lastName: "Smith" , department: "Engineering" , title: "Director" , phoneNumber: "555-123-4567" , startDate: today()-360 },
    { id: 2, firstName: "Michael" , lastName: "Johnson" , department: "Finance" , title: "Analyst" , phoneNumber: "555-987-6543" , startDate: today()-360 },
    { id: 3, firstName: "Mary", lastName: "Reed" , department: "Engineering" , title: "Software Engineer" , phoneNumber: "555-456-0123" , startDate: today()-240 },
  },
  a!formLayout(
    label: "Example: Add,Update, or Remove Employee Data",
    contents: {
      a!gridLayout(
        totalCount: count(local!employees),
        headerCells: {
          a!gridLayoutHeaderCell(label: "First Name" ),
          a!gridLayoutHeaderCell(label: "Last Name" ),
          a!gridLayoutHeaderCell(label: "Department" ),
          a!gridLayoutHeaderCell(label: "Title" ),
          a!gridLayoutHeaderCell(label: "Phone Number" ),
          a!gridLayoutHeaderCell(label: "Start Date", align: "RIGHT" ),
          /* For the "Remove" column */
          a!gridLayoutHeaderCell(label: "" )
        },
        /* Only needed when some columns need to be narrow */
        columnConfigs: {
          a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:3 ),
          a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:3 ),
          a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:3 ),
          a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:3 ),
          a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:3 ),
          a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:2 ),
          a!gridLayoutColumnConfig(width: "ICON")
        },
        /*
        * a!forEach() will take local!employee data and used that data to loop through an
        * expression that creates each row.
        *
        * When modifying the recipe to work with your data, you only need to change:
        * 1.) the number of fields in each row
        * 2.) the types of fields for each column (i.e. a!textField() for text data elements)
        * 3.) the fv!item elements. For example fv!item.firstName would change to fv!item.yourdata
        */
        rows: a!forEach(
          items: local!employees,
          expression: a!gridRowLayout(
            contents: {
              /* For the First Name Column*/
              a!textField(
                /* Labels are not visible in grid cells but are necessary to meet accessibility requirements */
                label: "first name " & fv!index,
                value: fv!item.firstName,
                saveInto: fv!item.firstName,
                required: true
              ),
              /* For the Last Name Column*/
              a!textField(
                label: "last name " & fv!index,
                value: fv!item.lastName,
                saveInto: fv!item.lastName,
                required:true
              ),
              /* For the Department Column*/
              a!dropdownField(
                label: "department " & fv!index,
                placeholderLabel: "-- Select -- ",
                choiceLabels: { "Corporate", "Engineering", "Finance", "Human Resources", "Professional Services", "Sales" },
                choiceValues: { "Corporate", "Engineering", "Finance", "Human Resources", "Professional Services", "Sales" },
                value: fv!item.department,
                saveInto: fv!item.department,
                required:true
              ),
              /* For the Title Column*/
              a!textField(
                label: "title " & fv!index,
                value: fv!item.title,
                saveInto: fv!item.title,
                required:true
              ),
              /* For the Phone Number Column*/
              a!textField(
                label: "phone number " & fv!index,
                placeholder:"555-456-7890",
                value: fv!item.phoneNumber,
                saveInto: fv!item.phoneNumber
              ),
              /* For the Start Date Column*/
              a!dateField(
                label: "start date " & fv!index,
                value: fv!item.startDate,
                saveInto: fv!item.startDate,
                required:true,
                align: "RIGHT"
              ),
              /* For the Removal Column*/
              a!richTextDisplayField(
                value: a!richTextIcon(
                  icon: "close",
                  altText: "delete " & fv!index,
                  caption: "Remove " & fv!item.firstName & " " & fv!item.lastName,
                  link: a!dynamicLink(
                    value: fv!index,
                    saveInto: {
                      a!save(local!employees, remove(local!employees, save!value))
                    }
                  ),
                  linkStyle: "STANDALONE",
                  color: "NEGATIVE"
                )
              )
            },
            id: fv!index
          )
        ),
        addRowlink: a!dynamicLink(
          label: "Add Employee",
          /*
           * For your use case, set the value to a blank instance of your CDT using
           * the type constructor, e.g. type!Employee(). Only specify the field
           * if you want to give it a default value e.g. startDate: today()+1.
           */
          value: {
            startDate: today() + 1
          },
          saveInto: {
            a!save(local!employees, append(local!employees, save!value))
          }
        ),
        rowHeader: 1
      )
    },
    buttons: a!buttonLayout(
      primaryButtons: a!buttonWidget(
        label: "Submit",
        submit: true
      )
    )
  )
)

you can use wherecontain for this i

wherecontains(tointeger(fv!row.id),tointeger(local!department.id)),