# template method pattern

> behavioral design pattern in object-oriented programming which defines the high-level skeleton of an operation to be implemented by helper methods

**Wikidata**: [Q771778](https://www.wikidata.org/wiki/Q771778)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Template_method_pattern)  
**Source**: https://4ort.xyz/entity/template-method-pattern

## Summary
The template method pattern is a behavioral design pattern in object-oriented programming that establishes the high-level skeleton of an operation. It allows specific steps of an algorithm to be implemented by helper methods while maintaining the overall structure of the process.

## Key Facts
- **Classification:** Behavioral design pattern and a subclass of object-oriented design.
- **Relationship:** It is a specific implementation of inversion of control (IoC).
- **Core Mechanism:** Defines a skeleton operation where general framework code calls into business-logic subroutines.
- **Technical Components:** Often utilizes abstract methods to define the steps to be implemented by helper methods.
- **Database Identifiers:** Freebase ID /m/015ywn; Microsoft Academic ID 21305988; OmegaWiki defined meaning 1271950.
- **Global Documentation:** Featured in 10 Wikipedia language editions, including English, French, German, and Spanish.
- **Sitelink Count:** 21.

## FAQs
### Q: What is the primary function of the template method pattern?
A: It defines the high-level skeleton of an operation within object-oriented programming. This structure allows specific steps of the operation to be filled in by helper methods without changing the algorithm's overall flow.

### Q: How does this pattern relate to inversion of control?
A: The template method pattern is a subclass of inversion of control. It applies the technique where general framework code manages the execution flow and calls into specific business-logic subroutines as needed.

### Q: What programming elements are commonly used to implement this pattern?
A: Implementation often relies on the use of abstract methods. These methods act as placeholders within the skeleton operation that must be defined by helper methods to complete the task.

## Why It Matters
The template method pattern is a fundamental concept in object-oriented design that addresses the need for structured yet flexible algorithm development. By defining a fixed skeleton for an operation, it ensures that the core logic of a process remains consistent across different implementations. Its significance is rooted in its use of inversion of control, a programming technique that shifts the responsibility of execution flow from individual subroutines to a general framework. 

This pattern is essential for developers who need to implement complex operations where the high-level steps are invariant, but the specific details of those steps may vary. It allows for the creation of extensible software frameworks where the "skeleton" is preserved while specific "helper methods" provide the necessary business logic. Its recognition across major academic and technical databases, such as Microsoft Academic and Freebase, as well as its documentation in over 10 languages, underscores its status as a standard architectural solution in software engineering.

## Notable For
- **Inversion of Control:** It serves as a primary example of a technique where framework code calls business-logic subroutines rather than the reverse.
- **Structural Integrity:** It is distinguished by its ability to maintain a rigid operation skeleton while allowing for modular helper method implementation.
- **Academic Indexing:** The pattern is uniquely identified in specialized knowledge bases including OmegaWiki (1271950) and the discontinued Microsoft Academic database.
- **Multilingual Standardization:** It is a globally recognized design pattern with dedicated documentation in languages ranging from Catalan and Bulgarian to Persian and Hungarian.

## Body

### Architectural Classification
The template method pattern is categorized as a behavioral design pattern within the field of object-oriented programming. It is formally classified as a subclass of both object-oriented design and inversion of control. 

### Mechanism of Operation
The pattern functions by establishing a high-level skeleton for a specific operation. The execution of this operation is managed by a general framework which dictates the sequence of events. 
- **Helper Methods:** These are used to implement the individual steps defined within the skeleton.
- **Abstract Methods:** The pattern often utilizes abstract methods to serve as the interface for the necessary helper methods.

### Inversion of Control (IoC) Integration
As a form of inversion of control, the template method pattern reverses the traditional flow of procedural programming. In this context, the general framework code is the active agent that calls into specific business-logic subroutines. This allows the high-level logic to be reused across different implementations while the specific details remain encapsulated within the helper methods.

### Technical Identifiers and Metadata
The pattern is well-documented in technical and academic literature. It is associated with Freebase ID /m/015ywn, which was referenced in academic contexts as early as October 2013. It maintains a sitelink count of 21 and is represented in a wide array of Wikipedia languages, including:
- English (en)
- German (de)
- French (fr)
- Spanish (es)
- Hungarian (hu)
- Bulgarian (bg)
- Catalan (ca)
- Persian (fa)
- Galician (gl)

## References

1. Freebase Data Dumps. 2013
2. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)