Init

.gitignore

+/vendor
+composer.phar
+composer.lock
+.DS_Store

.travis.yml

+language: php
+
+php:
+  - 5.4
+  - 5.5
+  - 5.6
+  - hhvm
+
+before_script:
+  - travis_retry composer self-update
+  - travis_retry composer install --prefer-source --no-interaction --dev
+
+script: phpunit

Readme.md

+# Installation
+
+add in composer
+```json
+    "repositories": [
+        {
+            "type": "vcs",
+            "url": "git@gitlab.top.md:terranet/rankable.git"
+        }
+    ],
+    "require": {
+        "terranet/rankable": "dev-master"
+    }
+```
+
+```sh
+composer update
+```
+
+### Usage example
+
+```php
+class Program extends Repository implements Translatable, Rankable
+{
+    use HasRankableField;
+
+    // optional
+    protected $rankableColumn = 'rank';
+
+    protected $rankableIncrementValue = 2;
+
+    protected $rankableGroupByColumn = 'member_id';
+}
+```
+
+now Program::all() will contain orderBy('rank', 'asc') statement
+
+to disable default orderBy statement use:
+```php
+Program::unRanked()
+```
+
+to sync rankings call:
+```php
+$model = new Program;
+$model->syncRanking([
+    1 => 3,
+    2 => 2,
+    3 => 1
+]);
+```
+where key => id, value => rank
\ No newline at end of file

composer.json

+{
+    "name": "terranet/rankable",
+    "description": "Provides useful methods to make an eloquent collection rankable",
+    "keywords": ["laravel", "rankable", "eloquent"],
+    "authors": [
+        {
+            "name": "Endi Hunter",
+            "email": "endi@terranet.md"
+        }
+    ],
+    "require": {
+        "php": ">=5.4.0",
+        "illuminate/database": "~5.0"
+    },
+    "autoload": {
+        "psr-0": {
+            "Terranet\\Rankable": "src/"
+        }
+    },
+    "minimum-stability": "stable"
+}

phpunit.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit backupGlobals="false"
+         backupStaticAttributes="false"
+         bootstrap="vendor/autoload.php"
+         colors="true"
+         convertErrorsToExceptions="true"
+         convertNoticesToExceptions="true"
+         convertWarningsToExceptions="true"
+         processIsolation="false"
+         stopOnFailure="false"
+         syntaxCheck="false"
+>
+    <testsuites>
+        <testsuite name="Package Test Suite">
+            <directory suffix=".php">./tests/</directory>
+        </testsuite>
+    </testsuites>
+</phpunit>

src/Terranet/Rankable/HasRankableField.php

+<?php namespace Terranet\Rankable;
+
+trait HasRankableField
+{
+    /**
+     * Get the rankable field name
+     *
+     * @return mixed
+     */
+    public function getRankableColumn()
+    {
+        return (isset($this->rankableColumn) ? $this->rankableColumn : 'rank');
+    }
+
+    /**
+     * Get the rankable field name
+     *
+     * @return mixed
+     */
+    public function getRankableIncrementValue()
+    {
+        return (isset($this->rankableIncrementValue) ? (int) $this->rankableIncrementValue : 1);
+    }
+
+    /**
+     * Calculate new rank value based on records group
+     *
+     * @ex.: Group comments rank by post_id
+     *
+     * @return array|null
+     */
+    public function getRankableGroupByColumn()
+    {
+        return (isset($this->rankableGroupByColumn) ? (array) $this->rankableGroupByColumn : null);
+    }
+
+    /**
+     * Synchronize ranking
+     *
+     * @param array $ranking - assoc array where key = record id, value = record rank value
+     * @return mixed
+     */
+    public function syncRanking(array $ranking = [])
+    {
+        foreach((array) $ranking as $id => $value)
+        {
+            $this
+                ->where($this->getKeyName(), '=', $id)
+                ->update([
+                    $this->getRankableColumn() => (int) $value
+                ]);
+        }
+    }
+
+    public static function bootHasRankableField()
+    {
+        static::addGlobalScope(new RankableScope);
+
+        static::updating(function(Rankable $model)
+        {
+            if ($model->isDirty($model->getRankableColumn()) && $oldValue = $model->getOriginal($model->getRankableColumn()))
+            {
+                // switch ranks in conflicts
+                $query = $model->newQuery();
+
+                $query = $model->applyRankGrouping($query, $model);
+
+                $query->where($model->getRankableColumn(), '=', (int) $model->getAttribute($model->getRankableColumn()));
+
+                $query->update([
+                    $model->getRankableColumn() => $oldValue
+                ]);
+            }
+        });
+
+        static::creating(function(Rankable $model)
+        {
+            $field = $model->getRankableColumn();
+
+            if (! $model->{$field})
+            {
+                $query = $model->newQuery();
+
+                $query = $model->applyRankGrouping($query, $model);
+
+                $value = (int) $query->max($field);
+
+                $model->{$field} = ($value + $model->getRankableIncrementValue());
+            }
+        });
+
+    }
+
+    protected function applyRankGrouping($query, $model)
+    {
+        if ($columns = (array) $model->getRankableGroupByColumn())
+        {
+            foreach($columns as $column)
+            {
+                $query->where($column, '=', $model->{$column});
+            }
+        }
+
+        return $query;
+    }
+}
\ No newline at end of file

src/Terranet/Rankable/Rankable.php

+<?php namespace Terranet\Rankable;
+
+interface Rankable
+{
+
+    /**
+     * Get the sortable field name
+     *
+     * @return mixed
+     */
+    public function getRankableColumn();
+
+    /**
+     * Get incrementing value
+     *
+     * @return mixed
+     */
+    public function getRankableIncrementValue();
+
+    /**
+     * Calculate new rank value based on records group
+     *
+     * @ex.: Group comments rank by post_id
+     *
+     * @return array|null
+     */
+    public function getRankableGroupByColumn();
+
+    /**
+     * Synchronize ranking
+     *
+     * @param array $ranking - assoc array where key = record id, value = record rank value
+     * @return mixed
+     */
+    public function syncRanking(array $ranking = []);
+
+}
\ No newline at end of file

src/Terranet/Rankable/RankableScope.php

+<?php namespace Terranet\Rankable;
+
+use Illuminate\Database\Eloquent\Builder;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\ScopeInterface;
+
+class RankableScope implements ScopeInterface
+{
+
+    protected $extensions = ['Unrank'];
+
+    /**
+     * Apply the scope to a given Eloquent query builder.
+     *
+     * @param  \Illuminate\Database\Eloquent\Builder $builder
+     * @param  \Illuminate\Database\Eloquent\Model $model
+     * @return void
+     */
+    public function apply(Builder $builder, Model $model)
+    {
+        $builder->orderBy($model->getRankableColumn());
+
+        $this->extend($builder);
+    }
+
+    /**
+     * Remove the scope from the given Eloquent query builder.
+     *
+     * @param  \Illuminate\Database\Eloquent\Builder $builder
+     * @param  \Illuminate\Database\Eloquent\Model $model
+     *
+     * @return void
+     */
+    public function remove(Builder $builder, Model $model)
+    {
+        $column = $model->getRankableColumn();
+
+        $query = $builder->getQuery();
+
+        foreach ((array) $query->orders as $key => $direction)
+        {
+            // If the where clause is a soft delete date constraint, we will remove it from
+            // the query and reset the keys on the wheres. This allows this developer to
+            // include deleted model in a relationship result set that is lazy loaded.
+            if ($this->isRankableOrder($key, $column))
+            {
+                unset($query->orders[$key]);
+
+                $query->orders = array_values($query->orders);
+            }
+        }
+    }
+
+    /**
+     * Extend the query builder with the needed functions.
+     *
+     * @param  \Illuminate\Database\Eloquent\Builder  $builder
+     * @return void
+     */
+    public function extend(Builder $builder)
+    {
+        foreach ($this->extensions as $extension)
+        {
+            $this->{"add{$extension}"}($builder);
+        }
+    }
+
+    /**
+     * Unrank .
+     *
+     * @param  \Illuminate\Database\Eloquent\Builder  $builder
+     * @return void
+     */
+    protected function addUnrank(Builder $builder)
+    {
+        $builder->macro('unRanked', function(Builder $builder)
+        {
+            $this->remove($builder, $builder->getModel());
+
+            return $builder;
+        });
+    }
+
+    private function isRankableOrder($key, $column)
+    {
+        return $column == $key;
+    }
+}
\ No newline at end of file

src/Terranet/Rankable/RankableServiceProvider.php

+<?php namespace Terranet\Rankable;
+
+use Illuminate\Support\ServiceProvider;
+
+class RankableServiceProvider extends ServiceProvider {
+
+	/**
+	 * Indicates if loading of the provider is deferred.
+	 *
+	 * @var bool
+	 */
+	protected $defer = true;
+
+	/**
+	 * Register the service provider.
+	 *
+	 * @return void
+	 */
+	public function register()
+	{
+		//
+	}
+
+	/**
+	 * Get the services provided by the provider.
+	 *
+	 * @return array
+	 */
+	public function provides()
+	{
+		return [];
+	}
+
+}