ios: update demos to display errors (#192)

Update the Swift and Objective-C demos to follow the UI logic implemented by envoyproxy/envoy-mobile#166. Resolves envoyproxy/envoy-mobile#168. ![Simulator Screen Shot - TestDevice - 2019-06-26 at 18 09 50](https://user-images.githubusercontent.com/2643476/60225905-a890ce00-983d-11e9-93ea-5e2c77829413.png) Signed-off-by: Michael Rebello <[email protected]> Signed-off-by: JP Simard <[email protected]>
envoyproxy · Nov 29, 2022 · 7bb7d6c · 7bb7d6c
1 parent fe8e671
commit 7bb7d6c
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Showing 5 changed files with 168 additions and 76 deletions.
diff --git a/mobile/.swiftlint.yml b/mobile/.swiftlint.yml
@@ -39,7 +39,6 @@ whitelist_rules:
   - force_unwrapping
   - generic_type_name
   - identical_operands
-  - identifier_name
   - implicit_getter
   - inert_defer
   - is_disjoint

diff --git a/mobile/examples/objective-c/hello_world/ViewController.mm b/mobile/examples/objective-c/hello_world/ViewController.mm
@@ -3,25 +3,29 @@
 
 #pragma mark - Constants
 
-NSString* _CELL_ID = @"cell-id";
-NSString* _ENDPOINT = @"http://localhost:9001/api.lyft.com/static/demo/hello_world.txt";
+NSString *_CELL_ID = @"cell-id";
+NSString *_ENDPOINT = @"http://localhost:9001/api.lyft.com/static/demo/hello_world.txt";
 
-#pragma mark - ResponseValue
+#pragma mark - Result
 
-/// Represents a response from the server.
-@interface ResponseValue : NSObject
-@property (nonatomic, strong) NSString* body;
-@property (nonatomic, strong) NSString* serverHeader;
+/// Represents a response from the server or an error.
+@interface Result : NSObject
+@property (nonatomic, assign) int identifier;
+@property (nonatomic, strong) NSString *body;
+@property (nonatomic, strong) NSString *serverHeader;
+@property (nonatomic, strong) NSString *error;
 @end
 
-@implementation ResponseValue
+@implementation Result
 @end
 
 #pragma mark - ViewController
 
 @interface ViewController ()
-@property (nonatomic, strong) NSMutableArray<ResponseValue*>* responses;
-@property (nonatomic, weak) NSTimer* requestTimer;
+@property (nonatomic, strong) NSURLSession *session;
+@property (nonatomic, assign) int requestCount;
+@property (nonatomic, strong) NSMutableArray<Result *> *results;
+@property (nonatomic, weak) NSTimer *requestTimer;
 @end
 
 @implementation ViewController
@@ -31,8 +35,14 @@ @implementation ViewController
 - (instancetype)init {
   self = [super init];
   if (self) {
-    self.responses = [NSMutableArray new];
-    self.tableView.allowsSelection = FALSE;
+    NSURLSessionConfiguration *configuration =
+        [NSURLSessionConfiguration defaultSessionConfiguration];
+    configuration.URLCache = nil;
+    configuration.timeoutIntervalForRequest = 10;
+    self.session = [NSURLSession sessionWithConfiguration:configuration];
+
+    self.results = [NSMutableArray new];
+    self.tableView.allowsSelection = NO;
   }
   return self;
 }
@@ -59,66 +69,109 @@ - (void)startRequests {
 }
 
 - (void)performRequest {
-  NSURLSession* session = [NSURLSession sharedSession];
   // Note that the request is sent to the envoy thread listening locally on port 9001.
-  NSURL* url = [NSURL URLWithString:_ENDPOINT];
-  NSURLRequest* request = [NSURLRequest requestWithURL:url];
+  NSURL *url = [NSURL URLWithString:_ENDPOINT];
+  NSURLRequest *request = [NSURLRequest requestWithURL:url];
   NSLog(@"Starting request to '%@'", url.path);
 
-  __weak ViewController* weakSelf = self;
-  NSURLSessionDataTask* task =
-      [session dataTaskWithRequest:request
-                 completionHandler:^(NSData* data, NSURLResponse* response, NSError* error) {
-                   if (error == nil && [(NSHTTPURLResponse*)response statusCode] == 200) {
-                     [weakSelf handleResponse:(NSHTTPURLResponse*)response data:data];
-                   } else {
-                     NSLog(@"Received error: %@", error);
-                   }
-                 }];
+  self.requestCount++;
+  int requestID = self.requestCount;
+
+  __weak ViewController *weakSelf = self;
+  NSURLSessionDataTask *task =
+      [self.session dataTaskWithRequest:request
+                      completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
+                        dispatch_async(dispatch_get_main_queue(), ^{
+                          [weakSelf handleResponse:(NSHTTPURLResponse *)response
+                                              data:data
+                                        identifier:requestID
+                                             error:error];
+                        });
+                      }];
   [task resume];
 }
 
-- (void)handleResponse:(NSHTTPURLResponse*)response data:(NSData*)data {
-  NSString* body = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
-  if (body == nil || response == nil) {
-    NSLog(@"Failed to deserialize response string");
+- (void)handleResponse:(NSHTTPURLResponse *)response
+                  data:(NSData *)data
+            identifier:(int)identifier
+                 error:(NSError *)error {
+  if (error != nil) {
+    NSLog(@"Received error: %@", error);
+    [self addResponseBody:nil serverHeader:nil identifier:identifier error:error.description];
     return;
   }
 
-  // Deserialize the response, which will include a `Server` header set by Envoy.
-  ResponseValue* value = [ResponseValue new];
-  value.body = body;
-  value.serverHeader = [[response allHeaderFields] valueForKey:@"Server"];
+  if (response.statusCode != 200) {
+    NSString *message = [NSString stringWithFormat:@"failed with status: %ld", response.statusCode];
+    [self addResponseBody:nil serverHeader:nil identifier:identifier error:message];
+    return;
+  }
+
+  NSString *body = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
+  if (body == nil) {
+    NSString *message = @"failed to deserialize body";
+    [self addResponseBody:nil serverHeader:nil identifier:identifier error:message];
+    return;
+  }
 
+  // Deserialize the response, which will include a `Server` header set by Envoy.
+  NSString *serverHeader = [[response allHeaderFields] valueForKey:@"Server"];
   NSLog(@"Response:\n%ld bytes\n%@\n%@", data.length, body, [response allHeaderFields]);
-  dispatch_async(dispatch_get_main_queue(), ^{
-    [self.responses addObject:value];
-    [self.tableView reloadData];
-  });
+  [self addResponseBody:body serverHeader:serverHeader identifier:identifier error:nil];
+}
+
+- (void)addResponseBody:(NSString *)body
+           serverHeader:(NSString *)serverHeader
+             identifier:(int)identifier
+                  error:(NSString *)error {
+  Result *result = [Result new];
+  result.identifier = identifier;
+  result.body = body;
+  result.serverHeader = serverHeader;
+  result.error = error;
+
+  [self.results insertObject:result atIndex:0];
+  [self.tableView reloadData];
 }
 
 #pragma mark - UITableView
 
-- (NSInteger)numberOfSectionsInTableView:(UITableView*)tableView {
+- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
   return 1;
 }
 
-- (NSInteger)tableView:(UITableView*)tableView numberOfRowsInSection:(NSInteger)section {
-  return self.responses.count;
+- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
+  return self.results.count;
 }
 
-- (UITableViewCell*)tableView:(UITableView*)tableView
-        cellForRowAtIndexPath:(NSIndexPath*)indexPath {
-  UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:_CELL_ID];
+- (UITableViewCell *)tableView:(UITableView *)tableView
+         cellForRowAtIndexPath:(NSIndexPath *)indexPath {
+  UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:_CELL_ID];
   if (cell == nil) {
     cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle
                                   reuseIdentifier:_CELL_ID];
   }
 
-  ResponseValue* response = self.responses[indexPath.row];
-  cell.textLabel.text = [NSString stringWithFormat:@"Response: %@", response.body];
-  cell.detailTextLabel.text =
-      [NSString stringWithFormat:@"'Server' header: %@", response.serverHeader];
+  Result *result = self.results[indexPath.row];
+  if (result.error == nil) {
+    cell.textLabel.text =
+        [NSString stringWithFormat:@"[%d] %@", result.identifier, result.body];
+    cell.detailTextLabel.text =
+        [NSString stringWithFormat:@"'Server' header: %@", result.serverHeader];
+
+    cell.textLabel.textColor = [UIColor blackColor];
+    cell.detailTextLabel.textColor = [UIColor blackColor];
+    cell.contentView.backgroundColor = [UIColor whiteColor];
+  } else {
+    cell.textLabel.text =
+        [NSString stringWithFormat:@"[%d]", result.identifier];
+    cell.detailTextLabel.text = result.error;
+
+    cell.textLabel.textColor = [UIColor whiteColor];
+    cell.detailTextLabel.textColor = [UIColor whiteColor];
+    cell.contentView.backgroundColor = [UIColor redColor];
+  }
+
   return cell;
 }
 

diff --git a/mobile/examples/swift/hello_world/Response.swift b/mobile/examples/swift/hello_world/Response.swift
diff --git a/mobile/examples/swift/hello_world/ResponseModels.swift b/mobile/examples/swift/hello_world/ResponseModels.swift
@@ -0,0 +1,12 @@
+/// Represents a response from the server.
+struct Response {
+  let id: Int
+  let body: String
+  let serverHeader: String
+}
+
+/// Error that was encountered when executing a request.
+struct RequestError: Error {
+  let id: Int
+  let message: String
+}
diff --git a/mobile/examples/swift/hello_world/ViewController.swift b/mobile/examples/swift/hello_world/ViewController.swift
@@ -5,7 +5,14 @@ private let kCellID = "cell-id"
 private let kURL = URL(string: "http://localhost:9001/api.lyft.com/static/demo/hello_world.txt")!
 
 final class ViewController: UITableViewController {
-  private var responses = [Response]()
+  private let session: URLSession = {
+    let configuration = URLSessionConfiguration.default
+    configuration.urlCache = nil
+    configuration.timeoutIntervalForRequest = 10
+    return URLSession(configuration: configuration)
+  }()
+  private var requestCount = 0
+  private var results = [Result<Response, RequestError>]()
   private var timer: Timer?
 
   override func viewDidLoad() {
@@ -27,25 +34,35 @@ final class ViewController: UITableViewController {
   }
 
   private func performRequest() {
-    // Note that the request is sent to the envoy thread listening locally on port 9001.
+    self.requestCount += 1
+    let requestID = self.requestCount
     let request = URLRequest(url: kURL)
+
+    // Note that the request is sent to the envoy thread listening locally on port 9001.
     NSLog("Starting request to '\(kURL.path)'")
-    let task = URLSession.shared.dataTask(with: request) { [weak self] data, response, error in
-      if let response = response as? HTTPURLResponse, response.statusCode == 200, let data = data {
-        self?.handle(response: response, with: data)
-      } else if let error = error {
-        NSLog("Received error: \(error)")
-      } else {
-        NSLog("Failed to receive data from the server")
+    self.session.dataTask(with: request) { [weak self] data, response, error in
+      DispatchQueue.main.async {
+        self?.handle(response: response, with: data, error: error, id: requestID)
       }
+    }.resume()
+  }
+
+  private func handle(response: URLResponse?, with data: Data?, error: Error?, id: Int) {
+    if let error = error {
+      return self.add(result: .failure(RequestError(id: id, message: "\(error)")))
     }
 
-    task.resume()
-  }
+    guard let response = response as? HTTPURLResponse, let data = data else {
+      return self.add(result: .failure(RequestError(id: id, message: "missing response data")))
+    }
+
+    guard response.statusCode == 200 else {
+      let error = RequestError(id: id, message: "failed with status \(response.statusCode)")
+      return self.add(result: .failure(error))
+    }
 
-  private func handle(response: HTTPURLResponse, with data: Data) {
     guard let body = String(data: data, encoding: .utf8) else {
-      return NSLog("Failed to deserialize response string")
+      return self.add(result: .failure(RequestError(id: id, message: "failed to deserialize body")))
     }
 
     let untypedHeaders = response.allHeaderFields
@@ -54,14 +71,14 @@ final class ViewController: UITableViewController {
       return (header.key as? String ?? String(describing: header.key), "\(header.value)")
     })
 
+    // Deserialize the response, which will include a `Server` header set by Envoy.
     NSLog("Response:\n\(data.count) bytes\n\(body)\n\(headers)")
+    self.add(result: .success(Response(id: id, body: body, serverHeader: headers["Server"] ?? "")))
+  }
 
-    // Deserialize the response, which will include a `Server` header set by Envoy.
-    let value = Response(body: body, serverHeader: headers["Server"] ?? "")
-    DispatchQueue.main.async {
-      self.responses.append(value)
-      self.tableView.reloadData()
-    }
+  private func add(result: Result<Response, RequestError>) {
+    self.results.insert(result, at: 0)
+    self.tableView.reloadData()
   }
 
   // MARK: - UITableView
@@ -71,7 +88,7 @@ final class ViewController: UITableViewController {
   }
 
   override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
-    return self.responses.count
+    return self.results.count
   }
 
   override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath)
@@ -80,9 +97,25 @@ final class ViewController: UITableViewController {
     let cell = tableView.dequeueReusableCell(withIdentifier: kCellID) ??
       UITableViewCell(style: .subtitle, reuseIdentifier: kCellID)
 
-    let response = self.responses[indexPath.row]
-    cell.textLabel?.text = "Response: \(response.body)"
-    cell.detailTextLabel?.text = "'Server' header: \(response.serverHeader)"
+    let result = self.results[indexPath.row]
+    switch result {
+    case .success(let response):
+      cell.textLabel?.text = "[\(response.id)] \(response.body)"
+      cell.detailTextLabel?.text = "'Server' header: \(response.serverHeader)"
+
+      cell.textLabel?.textColor = .black
+      cell.detailTextLabel?.textColor = .black
+      cell.contentView.backgroundColor = .white
+
+    case .failure(let error):
+      cell.textLabel?.text = "[\(error.id)]"
+      cell.detailTextLabel?.text = error.message
+
+      cell.textLabel?.textColor = .white
+      cell.detailTextLabel?.textColor = .white
+      cell.contentView.backgroundColor = .red
+    }
+
     return cell
   }
 }