Add preventDuplicate options

README.md

@@ -91,7 +91,10 @@ iconVariant         type: any             required: false       default: Materia
 hideIconVariant     type: boolean         required: false       default: false
 
 // event fired when user clicks on action button (if any)
-onClickAction       type: func            required: false       defualt: dismisses the snackbar
+onClickAction       type: func            required: false       default: dismisses the snackbar
+
+// hide or display duplicated messages
+preventDuplicate    type: boolean         required: false       default: false
 
 // Example of a Mui-Snackbar prop
 transitionDuration={{ exit: 380, enter: 400 }}
@@ -114,13 +117,16 @@ Adds a snackbar to the queue to be displayed to the user. It takes two arguments
 const key = this.props.enqueueSnackbar(message, options)
 
 // text of the snackbar
-message         type:string         required: true
+message                  type:string         required: true
 
 // object containing options with the following shape
-options:        type:object         required: false 
+options:                 type:object         required: false 
 
 // type of the snackbar
-options.variant type:string         oneOf(['default', 'error', 'success', 'warning', 'info'])
+options.variant          type:string         oneOf(['default', 'error', 'success', 'warning', 'info'])
+
+// hide or display this message if it's the same of the previous one
+options.preventDuplicate type:boolean        required: false
 
 // You can pass any material-ui Snackbar prop here, and they will be applied to this individual snackbar.
 // for example, this particular snackbar will get dismissed after 1 second.

index.d.ts

@@ -1,5 +1,4 @@
 import * as React from 'react';
-import { TransitionActions } from 'react-transition-group/Transition';
 import { SvgIconProps } from '@material-ui/core/SvgIcon';
 import { SnackbarProps, SnackbarClassKey } from '@material-ui/core/Snackbar';
 
@@ -11,6 +10,7 @@ export interface OptionsObject extends Omit<SnackbarProps, 'open' | 'message' |
     key?: string | number;
     variant?: VariantType;
     onClickAction?: Function;
+    preventDuplicate?: boolean;
 }
 
 type NotistackClassKey = 'variantSuccess'
@@ -23,7 +23,7 @@ export type CombinedClassKey = NotistackClassKey | SnackbarClassKey;
 
 export interface InjectedNotistackProps {
     onPresentSnackbar: (variant: VariantType, message: string) => void;
-    enqueueSnackbar: (message: string | React.ReactNode, options?: OptionsObject) => string | number;
+    enqueueSnackbar: (message: string | React.ReactNode, options?: OptionsObject) => string | number | null;
     closeSnackbar: (key: string | number) => void
 }
 
@@ -40,6 +40,7 @@ export interface SnackbarProviderProps
     iconVariant?: React.ComponentType<SvgIconProps>;
     hideIconVariant?: boolean;
     onClickAction?: Function;
+    preventDuplicate?: boolean;
 }
 
 export const SnackbarProvider: React.ComponentType<SnackbarProviderProps>;

src/SnackbarProvider.js

@@ -54,7 +54,14 @@ class SnackbarProvider extends Component {
      * can be: (default, success, error, warning, info)
      * @returns generated or user defined key referencing the new snackbar
      */
-    handleEnqueueSnackbar = (message, { key, ...options } = {}) => {
+    handleEnqueueSnackbar = (message, { key, preventDuplicate, ...options } = {}) => {
+        const shouldPreventDuplicate = preventDuplicate || this.props.preventDuplicate;
+        const isInQueue = !!this.queue.find(item => item.message === message);
+        const isDisplayed = !!this.state.snacks.find(item => item.message === message);
+        if (shouldPreventDuplicate && (isInQueue || isDisplayed)) {
+            return null;
+        }
+
         const id = key || new Date().getTime() + Math.random();
         this.queue.push({
             key: id,
@@ -227,12 +234,14 @@ SnackbarProvider.propTypes = {
     maxSnack: PropTypes.number,
     onClose: PropTypes.func,
     onExited: PropTypes.func,
+    preventDuplicate: PropTypes.bool,
 };
 
 SnackbarProvider.defaultProps = {
     maxSnack: 3,
     onClose: undefined,
     onExited: undefined,
+    preventDuplicate: false,
 };
 
 export default SnackbarProvider;