Added channel parameter to request (issue #77)

CONTRIBUTORS

@@ -10,6 +10,7 @@ Brantley Wells <brantleywells@gmail.com> @gitbrantley
 Brett Morgan <brettmorgan@google.com> @domesticmouse
 Chris Broadfoot <cbro@google.com> @broady
 Dave Holmes <daveholmes@google.com> @dh--
+Malcolm Windsor <malcolm@beoped.com> @mwindsor-beoped
 Mark McDonald <macd@google.com> @markmcd
 Nicolas Poirier <dev.nicolaspoirier@gmail.com> @NicolasPoirier
 Pulkit Bhuwalka <pulkit.bosco05@gmail.com> @nutsiepully

src/main/java/com/google/maps/GeoApiContext.java

@@ -47,6 +47,7 @@ public class GeoApiContext {
   private String apiKey;
   private String clientId;
   private UrlSigner urlSigner;
+  private String channel;
   private final OkHttpClient client = new OkHttpClient();
   private final RateLimitExecutorService rateLimitExecutorService;
 
@@ -60,6 +61,10 @@ public GeoApiContext() {
 
   <T, R extends ApiResponse<T>> PendingResult<T> get(ApiConfig config, Class<? extends R> clazz,
       Map<String, String> params) {
+    if(channel != null && !channel.isEmpty() && !params.containsKey("channel")){
+      params.put("channel", channel);
+    }
+
     StringBuilder query = new StringBuilder();
 
     for (Map.Entry<String, String> param : params.entrySet()) {
@@ -83,7 +88,11 @@ <T, R extends ApiResponse<T>> PendingResult<T> get(ApiConfig config, Class<? ext
 
     StringBuilder query = new StringBuilder();
 
+    boolean channelSet = false;
     for (int i = 0; i < params.length; i++) {
+      if(params[i]=="channel"){
+        channelSet = true;
+      }
       query.append('&').append(params[i]).append('=');
       i++;
 
@@ -95,6 +104,11 @@ <T, R extends ApiResponse<T>> PendingResult<T> get(ApiConfig config, Class<? ext
       }
     }
 
+    // Channel can be supplied per-request or per-context. We prioritize it from the request, so if it's not provided there, provide it here
+    if (channelSet == false && channel != null && !channel.isEmpty()) {
+      query.append("&channel=").append(channel);
+    }
+
     return getWithPath(clazz, config.fieldNamingPolicy, config.hostName, config.path,
         config.supportsClientId, query.toString());
   }
@@ -171,6 +185,15 @@ public GeoApiContext setEnterpriseCredentials(String clientId, String cryptograp
     return this;
   }
 
+  /**
+   * Sets the default channel for requests (can be overridden by requests).  Only useful for Google Maps for Work clients.
+   * @param channel  The channel to use for analytics
+   */
+  public GeoApiContext setChannel(String channel) {
+    this.channel = channel;
+    return this;
+  }
+
   /**
    * Sets the default connect timeout for new connections. A value of 0 means no timeout.
    *

src/main/java/com/google/maps/PendingResultBase.java

@@ -113,4 +113,15 @@ protected Map<String, String> params() {
   public final A language(String language) {
     return param("language", language);
   }
+
+  /**
+   * A channel to pass with the request.  channel is used by Google Maps API for Work
+   * users to be able to track usage across different applications with the same clientID.
+   * See: https://developers.google.com/maps/documentation/business/clientside/quota
+   *
+   * @param channel String to pass with the request for analytics
+   */
+  public A channel(String channel) {
+    return param("channel", channel);
+  }
 }