helloworld

gRPC in 3 minutes (Objective-C)

There are currently two ways to build projects with the gRPC Objective-C library:

• Cocoapods & Xcode
• Bazel (experimental)

Cocoapods

Installation

To run this example you should have Cocoapods installed, as well as the relevant tools to generate the client library code (and a server in another language, for testing). You can obtain the latter by following these setup instructions.

Hello Objective-C gRPC!

Here's how to build and run the Objective-C implementation of the Hello World example used in Getting started.

The example code for this and our other examples lives in the examples directory. Clone this repository at the latest stable release tag to your local machine by running the following commands:

$ git clone -b RELEASE_TAG_HERE https://github.com/grpc/grpc
$ cd grpc
$ git submodule update --init

Change your current directory to examples/objective-c/helloworld

$ cd examples/objective-c/helloworld

Try it!

To try the sample app, we need a gRPC server running locally. Let's compile and run, for example, the C++ server in this repository:

$ pushd ../../cpp/helloworld
$ make
$ ./greeter_server &
$ popd

Now have Cocoapods generate and install the client library for our .proto files:

$ pod install

(This might have to compile OpenSSL, which takes around 15 minutes if Cocoapods doesn't have it yet on your computer's cache.)

Finally, open the XCode workspace created by Cocoapods, and run the app. You can check the calling code in main.m and see the results in XCode's log console.

The code sends a HLWHelloRequest containing the string "Objective-C" to a local server. The server responds with a HLWHelloResponse, which contains a string that is then output to the log.

Bazel

Installation

To run the examples in Bazel, you should have Bazel installed.

Hello Objective-C gRPC!

Here's how to build and run the Objective-C implementation of the Hello World example.

The code for the Hello World example and others live in the examples directory. Clone this repository to your local machine by running the following commands:

$ git clone --recursive https://github.com/grpc/grpc

Next, change your directory to examples/objective-c

$ cd grpc/examples/objective-c

Now build the Hello World project:

$ bazel build :HelloWorld

Try it!

To run the Hello World sample properly, we need a local server. Let's compile and run the corresponding C++ server:

$ bazel run //examples/cpp/helloworld:greeter_server

To run the sample, you need to know the available simulator runtimes in your machine. You could either list the available runtimes yourself by running:

$ xcrun simctl list

Or just try running the app and it will let you know what is available in the error messages:

$ bazel run :HelloWorld

Note that running this command will build the project even if it is not built beforehand.

Finally, launch the app with one of the available runtimes:

$ bazel run :HelloWorld --ios_simulator_version='<runtime>' --ios_sumlator_device='<device>'

Tutorial

You can find a more detailed tutorial in gRPC Basics: Objective-C.