Configuring fixed width files as a data source

Fixed width files contain columns of data that are in fixed positions within the file (for example, "Emp/Last Name" uses the first 15 characters, "Emp/First Name" uses the next 15 characters).

About this task

A file data source can be used to populate tag values from the contents of complete files. Two file types – delimited and fixed width – are available when you are using a file data source. When you are use fixed width files, you must define the contents of the file so that HCL OneTest™ API knows how to extract the data from each line.


  1. Click Browse to select the data source file and select the Fixed Width option.

    If the test data source location is on a mapped network drive, you might get errors when running tests. To prevent any errors, ensure that the files are available on a local drive that can be accessed by HCL OneTest API.

  2. Indicate how you are going to define the data field locations in the source file:
    • Offset/Width: "offset" equals the number of characters that precede the field and "width" equals the number of characters that are used by the field.
    • Start Char/End Char: "start char" is the position directly before the field starts and "end char" is the last position of the field. "Start char" for the first field is always zero, which is one less than the first position in the file (that is, one). "End char" for all fields equals the length of the field plus its starting value, and this value is carried to "Start char" for the next field.
  3. Click Import to set the rules for determining the data locations. The Import Config dialog is displayed.
  4. Enter the rules or paste rules that were previously copied to the clipboard. Rules must be entered in the following format: Field Name<tab>value<tab>value

    As an example, take the following file content:

    Thompson       Aaron          Developer      72000     
    Miller         James          Developer      68000     
    Bryant         Samuel         Tester         54000     
    Jones          Richard        Tester         56500     

    In this file, "Emp/Last Name" uses the first 15 characters, "Emp/First Name" uses the next 15 characters, "Emp/Position" uses the next 12 characters, and "Emp/Salary" uses the last six characters. The fields are "padded" with spaces.

    The corresponding rules for this file are shown:

    Offset/Width Rules         Start Char/End Char Rules
    Emp/Last Name   0   15   Emp/Last Name   0   15
    Emp/First Name   15   30   Emp/First Name   15   30
    Emp/Position   30   42   Emp/Position   30   42
    Emp/Salary   42   48   Emp/Salary   42   48
    Note: Start Char/End Char rules are converted to Offset/Width figures when displayed in the data source configuration dialog.
  5. If the fields in your files are padded with extra characters so that they fill their space in the line, select the Trim cell padding option and specify the padding character – this character is removed when data is extracted.
  6. If Auto map new columns to tags at runtime is selected (the default value), then the values in any new columns that are added to the test data set are used as test data. This assumes that a tag exists that exactly matches each new column name and that the column count property is not set.
  7. If the number of test iterations can exceed the number of rows in the file, enable the Loop Data option to force HCL OneTest API to process the same rows over and over.
  8. Click Refresh to generate a preview of the data that are returned.
  9. Save the data source when finished, then see Creating tags from data source fields for details about copying column names to create tags from them.