Reuse of custom filter within the same query will result in a join error

[sjorskamphuis]

When using the same custom filter multiple times, the join statement will be appended twice to the query builder.

Example of the custom filter:

/**
     * @param Builder $query
     * @param         $method
     * @param         $clauseOperator
     * @param         $value
     *
     * @return Builder
     */
    public function filterStartLocation(Builder $query, $method, $clauseOperator, $value): Builder
    {
        // if clauseOperator is identical to false,
        // we are using a specific SQL method in its place (e.g. `in`, `between`)
        if ($clauseOperator === false) {
            $query->$method('locations.location_type_id', $value);
        } else {
            $query->$method('locations.location_type_id', $clauseOperator, $value);
        }

        return $query;
    }

As you can see, the custom filter will check the location_type within the location. the startLocation is an eloquent relation defined in the Model.

An error will occur when using this filter more then once within the same query:

The output of the Builder is:

Builder {#431 ▼
  #query: Builder {#417 ▼
    +connection: MySqlConnection {#128 ▶}
    +grammar: MySqlGrammar {#129 ▶}
    +processor: MySqlProcessor {#130}
    +bindings: array:7 [▶]
    +aggregate: null
    +columns: array:1 [▶]
    +distinct: false
    +from: "schedules"
    +joins: array:2 [▼
      0 => JoinClause {#877 ▼
        +type: "inner"
        +table: "locations"
        -parentQuery: Builder {#417}
        +connection: MySqlConnection {#128 ▶}
        +grammar: MySqlGrammar {#129 ▶}
        +processor: MySqlProcessor {#130}
        +bindings: array:7 [▶]
        +aggregate: null
        +columns: null
        +distinct: false
        +from: null
        +joins: null
        +wheres: array:1 [▼
          0 => array:5 [▼
            "type" => "Column"
            "first" => "schedules.end_location_id"
            "operator" => "="
            "second" => "locations.id"
            "boolean" => "and"
          ]
        ]
        +groups: null
        +havings: null
        +orders: null
        +limit: null
        +offset: null
        +unions: null
        +unionLimit: null
        +unionOffset: null
        +unionOrders: null
        +lock: null
        +operators: array:29 [▶]
        +useWritePdo: false
      }
      1 => JoinClause {#878 ▼
        +type: "inner"
        +table: "locations"
        -parentQuery: Builder {#417}
        +connection: MySqlConnection {#128 ▶}
        +grammar: MySqlGrammar {#129 ▶}
        +processor: MySqlProcessor {#130}
        +bindings: array:7 [▶]
        +aggregate: null
        +columns: null
        +distinct: false
        +from: null
        +joins: null
        +wheres: array:1 [▼
          0 => array:5 [▼
            "type" => "Column"
            "first" => "schedules.end_location_id"
            "operator" => "="
            "second" => "locations.id"
            "boolean" => "and"
          ]
        ]
        +groups: null
        +havings: null
        +orders: null
        +limit: null
        +offset: null
        +unions: null
        +unionLimit: null
        +unionOffset: null
        +unionOrders: null
        +lock: null
        +operators: array:29 [▶]
        +useWritePdo: false
      }
    ]
    +wheres: array:2 [▼
      0 => array:3 [▼
        "type" => "Nested"
        "query" => Builder {#886 ▼
          +connection: MySqlConnection {#128 ▶}
          +grammar: MySqlGrammar {#129 ▶}
          +processor: MySqlProcessor {#130}
          +bindings: array:7 [▶]
          +aggregate: null
          +columns: null
          +distinct: false
          +from: "schedules"
          +joins: null
          +wheres: array:1 [▼
            0 => array:5 [▼
              "type" => "Basic"
              "column" => "locations.location_type_id"
              "operator" => "="
              "value" => array:1 [▶]
              "boolean" => "and"
            ]
          ]
          +groups: null
          +havings: null
          +orders: null
          +limit: null
          +offset: null
          +unions: null
          +unionLimit: null
          +unionOffset: null
          +unionOrders: null
          +lock: null
          +operators: array:29 [▶]
          +useWritePdo: false
        }
        "boolean" => "and"
      ]
      1 => array:3 [▼
        "type" => "Nested"
        "query" => Builder {#871 ▼
          +connection: MySqlConnection {#128 ▶}
          +grammar: MySqlGrammar {#129 ▶}
          +processor: MySqlProcessor {#130}
          +bindings: array:7 [▶]
          +aggregate: null
          +columns: null
          +distinct: false
          +from: "schedules"
          +joins: null
          +wheres: array:1 [▼
            0 => array:5 [▼
              "type" => "Basic"
              "column" => "locations.location_type_id"
              "operator" => "="
              "value" => "8"
              "boolean" => "and"
            ]
          ]
          +groups: null
          +havings: null
          +orders: null
          +limit: null
          +offset: null
          +unions: null
          +unionLimit: null
          +unionOffset: null
          +unionOrders: null
          +lock: null
          +operators: array:29 [▶]
          +useWritePdo: false
        }
        "boolean" => "and"
      ]
    ]
    +groups: null
    +havings: null
    +orders: null
    +limit: null
    +offset: null
    +unions: null
    +unionLimit: null
    +unionOffset: null
    +unionOrders: null
    +lock: null
    +operators: array:29 [▶]
    +useWritePdo: false
  }
  #model: Schedule {#368 ▶}
  #eagerLoad: []
  #localMacros: []
  #onDelete: null
  #passthru: array:13 [▶]
  #scopes: []
  #removedScopes: []
}

Is there a workaround available for this issue?

--
Using Homestead with environment versions:

PHP:  7.2
Laravel: 5.6.39

[granith]

@sjors-k-nl did you find any workaround, I'm having same issue?