Merge pull request #23 from ladda-js/dedup-docs

Dedup docs

docs/README.md

@@ -12,6 +12,7 @@
 * [Advanced](/docs/advanced/README.md)
   * [Invalidation](/docs/advanced/Invalidation.md)
   * [Views](/docs/advanced/ViewOf.md)
+  * [Deduplication](/docs/advanced/Deduplication.md)
   * [Custom ID](/docs/advanced/CustomId.md)
   * [Plugins](/docs/advanced/Plugins.md)
     * [Cheat Sheet](/docs/advanced/Plugins-CheatSheet.md)

docs/advanced/Deduplication.md

@@ -0,0 +1,30 @@
+# Deduplication
+
+Ladda tries to optimize "READ" operations by deduplicating identical
+simultaneous requests and therefore reduce the load both on server and
+client.
+
+*Identical* means calling the same function with identical arguments.
+<br>
+*Simultaneous* means that another call has been made before the first
+call has been resolved or rejected.
+
+Given the following code, where `getUsers` is a "READ" operation:
+
+```javascript
+// Component 1
+api.user.getUsers();
+
+// Component 2
+api.user.getUsers();
+
+// Component 3
+api.user.getUsers();
+```
+
+Ladda will only make a single call to `getUsers` and distribute its
+result to all callers.
+
+
+This feature can be disabled on a global, an entity and a function
+level. Check the [Configuration Reference](/docs/basics/Configuration.md) for details.

docs/basics/Configuration.md

@@ -14,6 +14,9 @@ There are a handful optional options to configure Ladda. In a minimal configurat
 
 * **api** (required): An object of ApiFunctions, functions that communicate with an external service and return a Promise. The function name as key and function as value.
 
+* **noDedup**: `true | false` Disable [deduplication](/docs/advanced/Deduplication.md)
+  of all "READ" operations for this entity. Defaults to false.
+
 ## Method Configuration
 
 * **operation**: `"CREATE" | "READ" | "UPDATE" | "DELETE" | "NO_OPERATION"`. Default is `"NO_OPERATION"`.
@@ -29,6 +32,12 @@ There are a handful optional options to configure Ladda. In a minimal configurat
 call (if any), looking up items from the cache and only calling for
 items that are not yet present. Defaults to false.
 
+* **noDedup**: `true | false` Disable [deduplication](/docs/advanced/Deduplication.md)
+  a "READ" operation. Defaults to false.
+
 ## Ladda Configuration
 
 * **idField**: Specify the default property that contains the ID. By default this is `"id"`.
+
+* **noDedup**: `true | false` Disable [deduplication](/docs/advanced/Deduplication.md)
+  of "READ" operation for all entities. Defaults to false.

src/builder.js

@@ -73,6 +73,7 @@ const setEntityConfigDefaults = ec => {
     ttl: 300,
     invalidates: [],
     invalidatesOn: ['CREATE', 'UPDATE', 'DELETE'],
+    noDedup: false,
     ...ec
   };
 };
@@ -84,7 +85,8 @@ const setApiConfigDefaults = ec => {
     invalidates: [],
     idFrom: 'ENTITY',
     byId: false,
-    byIds: false
+    byIds: false,
+    noDedup: false
   };
 
   const writeToObjectIfNotSet = curry((o, [k, v]) => {
@@ -115,6 +117,7 @@ export const getEntityConfigs = compose( // exported for testing
 
 const getGlobalConfig = (config) => ({
   idField: 'id',
+  noDedup: false,
   useProductionBuild: process.NODE_ENV === 'production',
   ...(config.__config || {})
 });

src/validator.js

@@ -13,7 +13,7 @@ const isValidLogger = (logger) => logger && typeof logger.error === 'function';
 
 const getEntityNames = (entityConfigs) => Object.keys(entityConfigs);
 
-const checkApiDeclaration = (logger, entityConfigs, config, entityName, entity) => {
+const checkApiDeclaration = (logger, entityConfigs, entityName, entity) => {
   if (typeof entity.api !== 'object') {
     warn(logger, `No api definition found for entity ${entityName}`);
     return;
@@ -30,7 +30,7 @@ const checkApiDeclaration = (logger, entityConfigs, config, entityName, entity)
   compose(
     // eslint-disable-next-line no-unused-vars
     map_(([fnName, fn]) => {
-      const { operation, invalidates, idFrom, byId, byIds } = fn;
+      const { operation, invalidates, idFrom, byId, byIds, noDedup } = fn;
       const fullName = `${entityName}.${fnName}`;
       if (!isOperation(operation)) {
         warnApi(
@@ -51,6 +51,12 @@ const checkApiDeclaration = (logger, entityConfigs, config, entityName, entity)
         );
       }
 
+      if (typeof noDedup !== 'boolean') {
+        warnApi(
+          `${fullName}'s noDedup needs to be a boolean, was ${typeof noDedup}'`
+        );
+      }
+
       if (typeof idFrom !== 'function' && !isIdFromString(idFrom)) {
         warnApi(
           `${fullName} defines illegal idFrom. Use 'ENTITY', 'ARGS', or a function (Entity => id)`
@@ -70,7 +76,7 @@ const checkApiDeclaration = (logger, entityConfigs, config, entityName, entity)
   )(entity.api);
 };
 
-const checkViewOf = (logger, entityConfigs, config, entityName, entity) => {
+const checkViewOf = (logger, entityConfigs, entityName, entity) => {
   const { viewOf } = entity;
   if (viewOf && !isConfigured(viewOf, entityConfigs)) {
     warn(
@@ -81,7 +87,7 @@ const checkViewOf = (logger, entityConfigs, config, entityName, entity) => {
   }
 };
 
-const checkInvalidations = (logger, entityConfigs, config, entityName, entity) => {
+const checkInvalidations = (logger, entityConfigs, entityName, entity) => {
   const { invalidates, invalidatesOn } = entity;
   map_((entityToInvalidate) => {
     if (!isConfigured(entityToInvalidate, entityConfigs)) {
@@ -104,7 +110,7 @@ const checkInvalidations = (logger, entityConfigs, config, entityName, entity) =
   }, invalidatesOn);
 };
 
-const checkTTL = (logger, entityConfigs, config, entityName, entity) => {
+const checkTTL = (logger, entityConfigs, entityName, entity) => {
   if (typeof entity.ttl !== 'number') {
     warn(
       logger,
@@ -113,22 +119,43 @@ const checkTTL = (logger, entityConfigs, config, entityName, entity) => {
   }
 };
 
-const checkEntities = (logger, entityConfigs, config) => {
+const checkNoDedup = (logger, entityConfigs, entityName, entity) => {
+  if (typeof entity.noDedup !== 'boolean') {
+    warn(
+      logger,
+      `Entity ${entityName} specified noDedup as ${typeof entity.noDedup}, needs to be a boolean`
+    );
+  }
+};
+
+const checkEntities = (logger, entityConfigs) => {
   const checks = [
     checkApiDeclaration,
     checkViewOf,
     checkInvalidations,
-    checkTTL
+    checkTTL,
+    checkNoDedup
   ];
 
   compose(
     map_(([entityName, entity]) => {
-      map_((check) => check(logger, entityConfigs, config, entityName, entity), checks);
+      map_((check) => check(logger, entityConfigs, entityName, entity), checks);
     }),
     toPairs
   )(entityConfigs);
 };
 
+const checkGlobalConfig = (logger, config) => {
+  const { noDedup, idField } = config;
+  if (typeof noDedup !== 'boolean') {
+    warn(logger, 'noDedup needs to be a boolean, was string');
+  }
+
+  if (typeof idField !== 'string') {
+    warn(logger, 'idField needs to be a string, was boolean');
+  }
+};
+
 
 export const validateConfig = (logger, entityConfigs, config) => {
   // do not remove the process.NODE_ENV check here - allows uglifiers
@@ -137,5 +164,7 @@ export const validateConfig = (logger, entityConfigs, config) => {
     return;
   }
 
-  checkEntities(logger, entityConfigs, config);
+
+  checkGlobalConfig(logger, config);
+  checkEntities(logger, entityConfigs);
 };