CODEWITHSUNDEEP
design-patternsbuilder
Matěj Zábský
Matěj Zábský

Reputation: 17272

Real-world examples of the Builder pattern

I would like to see how is Builder pattern used in real world applications/APIs. The examples I found are all pizzas, cakes, cars et cetera (plus the parser example from the GoF book).

Could you please tell me about some usages of this patten in real-world applications/APIs, preferably from the world of C++, .NET or PHP (as those are the languages I'm familiar with).

Thanks.

Upvotes: 17

Views: 14162

Answers (3)

user991
user991

Reputation: 1369

Actually a very good real-life example is Active Record QueryBuilder example.

You can dig into the Laravel Eloquent module and check those Query builder classes...

A quick example of how it could look:

interface SqlQueryBuilder
{
    public function select(string $table, array $fields): SqlQueryBuilder;

    public function where(string $field, string $value, string $operator = '='): SqlQueryBuilder;

    public function limit(int $start, int $offset): SqlQueryBuilder;

    // ... other methods

    public function getSQL(): string;
}

class MysqlQueryBuilder implements SqlQueryBuilder
{
    // ...
}

class PostgresQueryBuilder extends MysqlQueryBuilder
{
    // ...
}

Upvotes: 3

Anoop
Anoop

Reputation: 5720

Builder pattern is used in javax.json.Json and javax.json.JsonBuilder classes while building Json objects.

Good explanation is at http://www.programcreek.com/java-api-examples/index.php?api=javax.json.JsonObjectBuilder and also check out its official documentation. 

JsonObjectBuilder b = Json.createObjectBuilder().
            add( "report", Json.createObjectBuilder().
                 add( "reportId", reportId ).
                 add( "title", title ).
                 add( "subtitle", subTitle == null ? "" : subTitle ).
                 add( "created", created.toString() ).
                 add( "description", description == null ? "" : description ).
                 add( "data", report )
            );
return b.build();

Upvotes: 4

Upgradingdave
Upgradingdave

Reputation: 13056

Update: I recently came across an even better example (imo). Checkout the JobBuilder and TriggerBuilder implementations in the Quartz scheduler package: http://quartz-scheduler.org/api/2.1.5/

Also, when I have time, just for fun/practice, I try to write examples of all GoF patterns in java. Just recently, I used the Builder pattern to make it easy to generate different types of Sitemaps (google site map vs, html site map, etc). The code is in java, but you might be useful: https://github.com/dparoulek/java-koans/tree/master/src/main/java/com/upgradingdave/koans/builder

Good question, I'd be interested in seeing more modern examples too.

Upvotes: 9

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