Validating Uploaded Excel & CSV Templates in ServiceNow with Flow Designer

[JAGRUTHIK]

Validating Uploaded Excel & CSV Templates in ServiceNow with Flow Designer

When end-users upload files in ServiceNow (through Catalog Items or forms), the files often need to match a specific template. Validating uploaded files before import prevents bad data, incomplete loads, and rework.

This article explains how to:

1. Extract column headers from uploaded Excel or CSV files.
2. Compare them with expected template headers.
3. Close the request as Incomplete if the template doesn’t match.

Flow Setup

The flow contains these steps:

1. Trigger → Service Catalog request.
2. Look Up Attachments → Get both uploaded and template files.
3. Custom Flow Actions:
• Extract Excel headers
• Extract CSV headers
• Validate headers
4. Decision Branch → Continue if valid, stop if invalid.

Here’s a simplified view of the flow:

Trigger (Catalog Item)

   ↓

Look up uploaded attachment

Look up template attachment

   ↓

Extract headers (Excel or CSV)

   ↓

Validate headers

   ↓

[If Invalid] Close Request as Incomplete

[If Valid]   Continue Import/Data Source

Flow Action 1: Extract Excel Headers

This action uses GlideExcelParser to fetch headers from an uploaded Excel file (.xlsx).

(function execute(inputs, outputs) {

    var parser = new sn_impex.GlideExcelParser();

    var attachment = new GlideSysAttachment();

    var attachmentStream = attachment.getContentStream(inputs.attachment);

    parser.parse(attachmentStream);

    var headers = parser.getColumnHeaders();

    var resultOutput = [];

    headers.forEach(function(ele){

        resultOutput.push(ele);

    });

    outputs.headers = resultOutput.toString(); 

})(inputs, outputs);

What it does:

• Reads the Excel file.
• Extracts the first row as headers.
• Returns headers as a comma-separated string.

Flow Action 2: Extract CSV Headers

This action handles .csv files using GlideTextReader.

(function execute(inputs, outputs) {

    var attachment = new GlideSysAttachment();

    var attachmentStream = attachment.getContentStream(inputs.attachment);

    // Read the CSV file

    var reader = new GlideTextReader(attachmentStream);

    // First line should be the header row

    var line = reader.readLine();

    var headers = [];

    if (line) {

        headers = line.split(";").map(function(h) {

            return h.trim();

        });

    }

    outputs.headers = headers.toString(); 

})(inputs, outputs);

What it does:

• Reads the first line of a CSV.
• Splits it by ; (configurable if your delimiter differs).
• Returns headers as a string.

Flow Action 3: Validate Template

This action checks if all expected fields exist in the uploaded file.

(function execute(inputs, outputs) {

    var headers = inputs.uploaded_doc_headers.toLowerCase().split(',');

    var fields = inputs.template_headers.toLowerCase().split(',');

    var valid = true;

    fields.forEach(function(field) {

        if (!headers.includes(field)) {

            valid = false;

        }

    });

    outputs.is_valid = valid;

})(inputs, outputs);

What it does:

• Compares uploaded headers with template headers.
• Returns true if all fields are present, false if not.

Flow Logic

• If is_valid = true → Continue with import or processing.
• If is_valid = false →
• Mark request as Closed Incomplete.
• Stop further processing.
• (Optional) Notify requester with details of missing fields.

Why This Matters

• Works with both Excel and CSV uploads.
• Prevents invalid data from entering staging or target tables.
• Provides early validation and clear feedback to users.
• Fully configurable (delimiter, expected headers, error handling).

Have questions or want to share your approach? Drop your thoughts in the comments!