Template Method pattern nini ne?

Question

IT Interview Practice · Accepted Answer

**Template Method** pattern yana bayyana **skeleton na algorithm** a cikin tushe class, yana barde subclasses don cika matakan takaici ba tare da canja yaren gida ba. Yana kama process gida daidai tare da bada damar gyara matakan mutane daban daban.

## Abin da Template Method pattern yake yi

```text
TEMPLATE METHOD → define an algorithm's overall STRUCTURE in a base method, with some STEPS
left for subclasses to implement:
  → the base class controls the overall flow (the "template")
  → subclasses override specific STEPS (the parts that vary)
  → the algorithm's structure is FIXED; the steps are customizable
→ "common process, customizable steps"
```

## Misali

```js
// base class defines the algorithm skeleton
class DataProcessor {
  process() {                    // the template method (fixed structure)
    const data = this.read();    // step (subclass implements)
    const result = this.transform(data);  // step (subclass implements)
    this.save(result);           // step (subclass implements)
  }
  read() { throw 'implement'; }       // steps to be overridden
  transform(d) { throw 'implement'; }
  save(r) { throw 'implement'; }
}
// subclasses provide the specific steps; the overall process is the same
class CsvProcessor extends DataProcessor { read() {...} transform() {...} save() {...} }
```

## Fa'ida da amfani

```text
BENEFITS:
  ✓ CODE REUSE → common algorithm structure defined ONCE (in the base); no duplication
  ✓ CONSISTENCY → all subclasses follow the same overall process
  ✓ CUSTOMIZATION → vary specific steps without rewriting the whole algorithm
  ✗ uses inheritance (consider composition/strategy alternatives for flexibility)
USES → frameworks (define a process, you fill in hooks); data processing pipelines;
  lifecycle methods (e.g. framework hooks/callbacks); workflows with varying steps
```

## Dalilin da ya dace

Ganewa Template Method pattern yana da mahimmanci saboda shine **design pattern mai amfani** don kama processes gida tare da matakan da za a iya gyara, gida a cikin frameworks, don haka yana da alaka design knowledge.

Template Method pattern yana bayyana skeleton na algorithm a cikin tushe class yayin barin subclasses su cika matakan takaici — kama process gida yayin barin gyara-gida na sassa daban daban.

Ganewa abin da yake yi (tushe class yana sarrafa jiya overall daidai-daidai a matsayin template na tsayaye, tare da subclasses marubuta matakan da suka bambanta) shine ilimin tsohon.

Ganewa **fa'ida** yana da mahimmanci: **sake amfani da code** (common algorithm structure defined sau daya a cikin tushe, kada kawar da maimaita a subclasses da suka raba process), **kwatancewa** (duk subclasses suna bin process gida iri-iri — tabbatar da daidaito), da **gyara-gida** (sauya matakan takaici ba tare da sake rubuta algorithm gaida ba).

Wadannan suna sanya Template Method bakowar idan kana da process wanda shi ne iri-iri overall amma yana bambanta a bayani.

Ganewa caveat cewa yana amfani da inheritance (tare da composition/Strategy a matsayin zabin don flexibility da yawa) yana nuna balanced judgment.

Ganewa **amfani** — **frameworks** (bayyana process inda ka cika hooks — pattern gida na framework gaida), data processing pipelines, **lifecycle methods** (framework hooks da callbacks, kamar lifecycle methods a cikin UI frameworks), da workflows tare da matakan bambanta — yana haffe applicability dinsu.

Template Method pattern yana kasua ne a cikin frameworks, inda framework yana bayyana jiya overall da kai implement hooks takaici (pattern da ka samu duk da lokacin da ka rubutawa framework lifecycle ko hook methods).

Saboda Template Method pattern shine design pattern mai amfani don kama processes gida tare da matakan da za a iya gyara (sake amfani da code, kwatancewa, gyara-gida), gida a cikin frameworks (lifecycle methods, hooks), da saboda ganewa shi da amfani dinsu yana da alaka don ganewa da amfani wannan framework-common pattern, ganewa Template Method pattern yana dace, practically-relevant design knowledge — pattern mai amfani don common processes tare da matakan daban, takaice ne a cikin frameworks (lifecycle hooks), da important design knowledge don kama shared algorithm structure yayin barin step customization.

Abin da Template Method pattern yake yi

Misali

Fa'ida da amfani

Dalilin da ya dace

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