Removing Dependency from SDK Core Project

- Copied files required for Rest API SDK
- Removed PPApiContext and directly connected APIContext with PPConfigManager
- Removed duplicate data storage of configuration and credentials.
- Code Style Fixes
- Remove build.xml file as it is not required anymore
- Updated the samples
- Updated the documentations

lib/PayPal/Common/PPModel.php

@@ -0,0 +1,148 @@
+<?php
+
+namespace PayPal\Common;
+
+/**
+ * Generic Model class that all API domain classes extend
+ * Stores all member data in a Hashmap that enables easy
+ * JSON encoding/decoding
+ */
+class PPModel
+{
+
+    private $_propMap = array();
+
+    /**
+     * Magic Get Method
+     *
+     * @param $key
+     * @return mixed
+     */
+    public function __get($key)
+    {
+        return $this->_propMap[$key];
+    }
+
+    /**
+     * Magic Set Method
+     *
+     * @param $key
+     * @param $value
+     */
+    public function __set($key, $value)
+    {
+        $this->_propMap[$key] = $value;
+    }
+
+    /**
+     * Magic isSet Method
+     *
+     * @param $key
+     * @return bool
+     */
+    public function __isset($key)
+    {
+        return isset($this->_propMap[$key]);
+    }
+
+    /**
+     * Magic Unset Method
+     *
+     * @param $key
+     */
+    public function __unset($key)
+    {
+        unset($this->_propMap[$key]);
+    }
+
+    /**
+     * Converts Params to Array
+     *
+     * @param $param
+     * @return array
+     */
+    private function _convertToArray($param)
+    {
+        $ret = array();
+        foreach ($param as $k => $v) {
+            if ($v instanceof PPModel) {
+                $ret[$k] = $v->toArray();
+            } else if (is_array($v)) {
+                $ret[$k] = $this->_convertToArray($v);
+            } else {
+                $ret[$k] = $v;
+            }
+        }
+        return $ret;
+    }
+
+    /**
+     * Fills object value from Array list
+     *
+     * @param $arr
+     * @return $this
+     */
+    public function fromArray($arr)
+    {
+
+        foreach ($arr as $k => $v) {
+            if (is_array($v)) {
+                $clazz = PPReflectionUtil::getPropertyClass(get_class($this), $k);
+
+                if (PPArrayUtil::isAssocArray($v)) {
+                    /** @var self $o */
+                    $o = new $clazz();
+                    $o->fromArray($v);
+                    $this->__set($k, $o);
+                } else {
+                    $arr = array();
+                    foreach ($v as $nk => $nv) {
+                        if (is_array($nv)) {
+                            $o = new $clazz();
+                            $o->fromArray($nv);
+                            $arr[$nk] = $o;
+                        } else {
+                            $arr[$nk] = $nv;
+                        }
+                    }
+                    $this->__set($k, $arr);
+                }
+            } else {
+                $this->$k = $v;
+            }
+        }
+        return $this;
+    }
+
+    /**
+     * Fills object value from Json string
+     *
+     * @param $json
+     * @return $this
+     */
+    public function fromJson($json)
+    {
+        return $this->fromArray(json_decode($json, true));
+    }
+
+    /**
+     * Returns array representation of object
+     *
+     * @return array
+     */
+    public function toArray()
+    {
+        return $this->_convertToArray($this->_propMap);
+    }
+
+    /**
+     * Returns object JSON representation
+     *
+     * @param int $options http://php.net/manual/en/json.constants.php
+     * @return string
+     */
+    public function toJSON($options = 0)
+    {
+        return json_encode($this->toArray(), $options);
+    }
+}