]> gerrit.simantics Code Review - simantics/district.git/blobdiff - org.simantics.maps.server/node/node-v4.8.0-win-x64/node_modules/npm/node_modules/inflight/README.md
Adding integrated tile server
[simantics/district.git] / org.simantics.maps.server / node / node-v4.8.0-win-x64 / node_modules / npm / node_modules / inflight / README.md
diff --git a/org.simantics.maps.server/node/node-v4.8.0-win-x64/node_modules/npm/node_modules/inflight/README.md b/org.simantics.maps.server/node/node-v4.8.0-win-x64/node_modules/npm/node_modules/inflight/README.md
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+# inflight
+
+Add callbacks to requests in flight to avoid async duplication
+
+## USAGE
+
+```javascript
+var inflight = require('inflight')
+
+// some request that does some stuff
+function req(key, callback) {
+  // key is any random string.  like a url or filename or whatever.
+  //
+  // will return either a falsey value, indicating that the
+  // request for this key is already in flight, or a new callback
+  // which when called will call all callbacks passed to inflightk
+  // with the same key
+  callback = inflight(key, callback)
+
+  // If we got a falsey value back, then there's already a req going
+  if (!callback) return
+
+  // this is where you'd fetch the url or whatever
+  // callback is also once()-ified, so it can safely be assigned
+  // to multiple events etc.  First call wins.
+  setTimeout(function() {
+    callback(null, key)
+  }, 100)
+}
+
+// only assigns a single setTimeout
+// when it dings, all cbs get called
+req('foo', cb1)
+req('foo', cb2)
+req('foo', cb3)
+req('foo', cb4)
+```