Sisendfilter

Sisendfilter, in Estonian IT terminology, refers to a software component that processes inbound data before it is consumed by an application. It is used to ensure data quality, integrity, and security across data flows such as user input, API payloads, and sensor streams.

A sisendfilter typically performs normalization, validation, sanitization, type conversion, and sometimes encoding. It may enforce a schema, check length, allowed values, and reject or transform invalid data, returning a sanitized value or producing an error or exception.

Common implementations use a filter chain or middleware pattern, where multiple filters are applied in sequence. Filters may be configured declaratively, loaded at runtime, and composed to form a processing pipeline. They can operate synchronously or asynchronously.

Typical use cases include web form processing, API input validation, message ingestion, and data pipelines. In embedded or real-time systems, input filters help ensure constraints before the data reaches critical components.

Important design considerations include performance, error reporting, and security. Proper ordering is essential, with normalization and type conversion before validation, and sanitization to prevent injection attacks. Filters should be auditable and maintain backward compatibility.

See also: input validation, data sanitization, filter chain, middleware, data integrity. There is no single standard for sisendfilter; implementations vary between languages and frameworks, but the core goal is to gate and shape inbound data before use.