Issue #7

- Added a precision method onto Target class.

README.md

@@ -51,6 +51,12 @@ use OceanDBA\Graphitti\Metrics\Target;
 $target = Target::make('oceandba.server1.load', 'Server-load-1');
 ```
 
+You may also add a precision to the Target object which will serve to round DataPoints when retrieved.
+
+```php
+$target = Target::make('oceandba.server1.load', 'Server-load-1')->precision(2);
+```
+
 The ```Target``` takes two parameters :
 1) The path
 2) An optional name for the Target

src/Metrics/Target.php

@@ -27,16 +27,25 @@ class Target implements UrlParameter, Metric
      */
     protected $target;
 
+    /**
+     * The final precision when rendering to DataPoints.
+     *
+     * @var int
+     */
+    protected $precision;
+
     /**
      * Target constructor.
      *
      * @param string $target
      * @param string $name
+     * @param int    $precision
      */
-    public function __construct(string $target, string $name = null)
+    public function __construct(string $target, string $name = null, int $precision = null)
     {
         $this->target = $target;
         $this->name = $name;
+        $this->precision = $precision;
     }
 
     /**
@@ -74,6 +83,30 @@ public function name(): string
         return $this->name;
     }
 
+    /**
+     * Return the Precision used for this Target.
+     *
+     * @param int $precision
+     *
+     * @return self
+     */
+    public function precision(int $precision): self
+    {
+        $this->precision = $precision;
+
+        return $this;
+    }
+
+    /**
+     * Return the Precision used for this Target.
+     *
+     * @return int|null
+     */
+    public function getPrecision(): ?int
+    {
+        return $this->precision;
+    }
+
     /**
      * Get the current value of the parameter as string for Graphite.
      *

src/Series/DataPoints.php

@@ -49,8 +49,8 @@ public function __construct(Target $target, Collection $points)
     public static function make(Target $target, array $data = null): self
     {
         $data = $data ?? [];
-        $points = collect($data['datapoints'] ?? [])->transform(function ($point) {
-            return Point::make($point[1], $point[0] ?? 0.0);
+        $points = collect($data['datapoints'] ?? [])->transform(function ($point) use ($target) {
+            return Point::make($point[1], $point[0] ?? 0.0, $target->getPrecision());
         });
 
         return new static($target, $points);

src/Series/Point.php

@@ -60,13 +60,14 @@ public function value(): float
      *
      * @param int   $timestamp
      * @param float $value
+     * @param int   $precision
      *
      * @return Point
      */
-    public static function make(int $timestamp, float $value): self
+    public static function make(int $timestamp, float $value, int $precision = null): self
     {
         $time = Carbon::createFromTimestamp($timestamp);
-        $value = round($value, 2);
+        $value = is_null($precision) ? $value : round($value, $precision);
 
         return new static($time, $value);
     }

tests/Feature/Renderer/PointsTest.php

@@ -27,6 +27,28 @@ public function test_it_returns_datapoints_collection()
         $this->assertCount(3, $dataPointsCollection);
     }
 
+    public function test_it_follows_defined_precision()
+    {
+        /** @var Points $points */
+        $points = app(Points::class)->handler($this->mockPoints());
+        $dataPointsCollection = $points->addTarget(Target::make('oceandba.server1.load', 'Server-load-1')->precision(2))
+                                       ->addTarget(Target::make('oceandba.server2.load', 'Server-load-2'))
+                                       ->from('-1h')
+                                       ->until('now')
+                                       ->addParameter('maxDataPoints', 50)
+                                       ->render();
+
+        $this->assertEquals(
+            [0.54, 1.07, 0.0],
+            $dataPointsCollection->first()->points()->map->value()->all()
+        );
+
+        $this->assertEquals(
+            [0.48166666666666674, 0.6614285714285714, 0.7287499999999999],
+            $dataPointsCollection->last()->points()->map->value()->all()
+        );
+    }
+
     /**
      * Return mocks of datapoints.
      *