How to Create a Cells FOSS Model in Rust

Aspose.Cells FOSS for Rust models a workbook as a tree of typed objects — worksheets, cell collections, and rule objects such as validations. This guide builds a complete workbook model from scratch: typed cell values, data validation rules over CellArea ranges, and a saved XLSX file at the end.

Step-by-Step Guide

Step 1: Install the Package

Add the crate to your Cargo.toml as a Cargo git dependency (the crate is not yet published on crates.io):

# Cargo.toml
[dependencies]
aspose-cells-foss-rust = { git = "https://github.com/aspose-cells-foss/Aspose.Cells-FOSS-for-Rust" }

Then build the project:

cargo build

Step 2: Import Required Classes

use aspose_cells_foss_rust::{
    CellArea, OperatorType, ValidationAlertType, ValidationType, Workbook,
};
use std::error::Error;

Step 3: Create the Workbook and Cell Data

Start the model with a Workbook, name the sheet, and write typed values:

let mut workbook = Workbook::new();
{
    let mut worksheets = workbook.get_worksheets_mut();
    let sheet = worksheets.get(0)?;
    sheet.set_name("Validation Sheet")?;
    let mut cells = sheet.get_cells_mut();
    cells.get("A1")?.put_value_string("Open")?;
    cells.get("B2")?.put_value_i32(5)?;
    cells.get("G1")?.put_value_string("ABCDE")?;
}

Step 4: Add a List Validation

Validation rules attach to CellArea ranges through the sheet’s validation collection. A list validation constrains cells to fixed choices with an in-cell dropdown:

let mut validations = sheet.get_validations();
let list_index = validations.add(CellArea::create_cell_area_a1("A1", "A3")?)?;
let mut list_validation = validations
    .get(list_index)
    .expect("validation should exist");
list_validation.set_type(ValidationType::List);
list_validation.set_formula1("\"Open,Closed\"");
list_validation.set_in_cell_drop_down(true);
list_validation.set_show_input(true);
list_validation.set_input_title("Status");
list_validation.set_input_message("Pick a status");

Step 5: Add Range and Custom Rules

OperatorType drives numeric range rules, and ValidationType::Custom accepts a formula; ValidationAlertType selects the alert severity:

let decimal_index = validations.add(CellArea::create_cell_area_a1("B2", "C3")?)?;
let mut decimal_validation = validations
    .get(decimal_index)
    .expect("validation should exist");
decimal_validation.set_type(ValidationType::Decimal);
decimal_validation.set_operator(OperatorType::Between);
decimal_validation.set_formula1("1.5");
decimal_validation.set_formula2("9.5");
decimal_validation.set_show_error(true);

let custom_index = validations.add(CellArea::create_cell_area_a1("G1", "G1")?)?;
let mut custom_validation = validations
    .get(custom_index)
    .expect("validation should exist");
custom_validation.set_type(ValidationType::Custom);
custom_validation.set_alert_style(ValidationAlertType::Warning);
custom_validation.set_formula1("LEN(G1)<=5");

Step 6: Save the Model

workbook.save("validations-sample.xlsx")?;

The saved file opens in Excel with the dropdowns, range checks, and custom rule active.

Common Issues and Fixes

The validation has no visible effect in Excel. Enable the prompts: set_show_input / set_show_error control whether the input hint and error alert appear.

A rule should cover several separate ranges. Add more ranges to an existing rule with add_area and additional CellArea::create_cell_area_a1 ranges.

Borrow errors while adding validations. Keep the worksheet borrow scoped: fetch get_validations inside the same block as the mutations, and save the workbook after the block ends.

List choices are misread as a formula. Wrap the choices in escaped quotes exactly as shown: set_formula1("\"Open,Closed\"").

Frequently Asked Questions

Which validation types are available?

ValidationType includes List, Decimal, and Custom as shown here — list dropdowns, numeric ranges via OperatorType, and formula-based rules.

Can validations show custom messages?

Yes — set_input_title / set_input_message control the prompt, and set_error_title / set_error_message control the failure alert.

Does the model survive a round-trip?

Yes. Save with Workbook::save and reload with Workbook::load_xlsx; the validation rules are preserved in the XLSX file.