Merge pull request #160 from microsoftgraph/Calling_Pattern_Doc

Added calling pattern doc

Author: muthurathinam

README.md

@@ -169,7 +169,7 @@ try {
 }
 ```
 
-For more information, refer: [Calling Pattern](docs/CallingPattern.md), [Actions](docs/Actions.md), [Query Params](docs/QueryParameters.md), [API Methods](docs/APIMethods.md) and [more](docs/).
+For more information, refer: [Calling Pattern](docs/CallingPattern.md), [Actions](docs/Actions.md), [Query Params](docs/QueryParameters.md), [API Methods](docs/OtherAPIs.md) and [more](docs/).
 
 ## Documentation
 

docs/CallingPattern.md

@@ -0,0 +1,49 @@
+# Calling Pattern
+
+All calls to Microsoft Graph are chained together starting with **.api()**, then chain [query parameters](./QueryParameters.md) and end with an [action](./Actions.md).
+
+## Path supports the following formats
+
+* `me`
+* `/me`
+* `https://graph.microsoft.com/v1.0/me`
+* `https://graph.microsoft.com/beta/me`
+* `me/events?$filter=startswith(subject, "Adventure")`
+
+## Promise based calling
+
+Getting user details with `async`/`await`,
+
+```typescript
+try {
+    let res = await client.api("/me").get();
+    console.log(res);
+} catch (error) {
+    throw error;
+}
+```
+
+Getting user details with `then`/`catch`,
+
+```typescript
+client
+    .api('/me')
+    .get()
+    .then((res) => {
+        console.log(res);
+    }).catch((err) => {
+        console.log(err);
+    });
+```
+
+## Callback based calling
+
+Getting user details by passing `callback`,
+
+```typescript
+client
+    .api('/me')
+    .get((err, res) => {
+        console.log(res);
+    });
+```