add "before" events

docs/documentation/Events.md

@@ -22,6 +22,17 @@ dataTable.on('datatable.page', function(page) {
 });
 ```
 
+### `datatable.page:before`
+Fires before page change.
+
+A single argument is available which returns the page number:
+
+```javascript
+dataTable.on('datatable.page:before', function(page) {
+    //
+});
+```
+
 ### `datatable.perpage`
 Fires when the perPage option is changed with the dropdown. A single argument returns the per-page value:
 
@@ -31,9 +42,21 @@ dataTable.on('datatable.perpage', function(perpage) {
 });
 ```
 
+### `datatable.perpage:before`
+Fires before the perPage option is changed with the dropdown. A single argument returns the per-page value:
+
+```javascript
+dataTable.on('datatable.perpage:before', function(perpage) {
+    //
+});
+```
+
 ### `datatable.refresh`
 Fires when the `.refresh()` method is called.
 
+### `datatable.refresh:before`
+Fires before the `.refresh()` method is called.
+
 ### `datatable.search`
 Fires on keyup during a search.
 
@@ -45,6 +68,17 @@ dataTable.on('datatable.search', function(query, matched) {
 });
 ```
 
+### `datatable.search:before`
+Fires on keyup before a search.
+
+Two arguments are available: `query` which returns the query string entered and `matched` which returns an array of rows containing the matched string:
+
+```javascript
+dataTable.on('datatable.search:before', function(query, matched) {
+    //
+});
+```
+
 ### `datatable.selectrow`
 Fires when user selects a row - either by mouse click on a row or using `Space`/`Enter` during keyboard based navigation (requires option [[rowNavigation]]).
 
@@ -72,3 +106,6 @@ dataTable.on('datatable.sort', function(column, direction) {
 
 ### `datatable.update`
 Fires when the `.update()` method is called.
+
+### `datatable.update:before`
+Fires before the `.update()` method is called.

src/datatable.ts

@@ -499,6 +499,7 @@ export class DataTable {
             if (selector && selector instanceof HTMLSelectElement) {
                 // Change per page
                 selector.addEventListener("change", () => {
+                    this.emit("datatable.perpage:before", this.options.perPage)
                     this.options.perPage = parseInt(selector.value, 10)
                     this.update()
 
@@ -696,6 +697,8 @@ export class DataTable {
      * @return {Void}
      */
     update(measureWidths = false) {
+        this.emit("datatable.update:before")
+
         if (measureWidths) {
             this.columns._measureWidths()
             this.hasRows = Boolean(this.data.data.length)
@@ -776,6 +779,7 @@ export class DataTable {
      * Perform a simple search of the data set
      */
     search(term: string, columns: (number[] | undefined ) = undefined) {
+        this.emit("datatable.search:before", term, this._searchData)
 
         if (!term.length) {
             this._currentPage = 1
@@ -811,6 +815,8 @@ export class DataTable {
         })).filter(query => query.terms.length
         )
 
+        this.emit("datatable.multisearch:before", queries, this._searchData)
+
         this._searchQueries = queries
 
         if (!queries.length) {
@@ -889,6 +895,8 @@ export class DataTable {
      * Change page
      */
     page(page: number, lastRowCursor = false) {
+        this.emit("datatable.page:before", page)
+
         // We don't want to load the current page again.
         if (page === this._currentPage) {
             return false
@@ -971,6 +979,8 @@ export class DataTable {
      * Refresh the instance
      */
     refresh() {
+        this.emit("datatable.refresh:before")
+
         if (this.options.searchable) {
             const inputSelector = classNamesToSelector(this.options.classes.input)
             const inputs: HTMLInputElement[] = Array.from(this.wrapperDOM.querySelectorAll(inputSelector))