Method _historyTableAdd

src/AutoNumeric.js:1648–1701

* Save the current raw value into the history table, along with the selection information. * * If the user has done some undos and tries to enter: * - a new and different number than the 'next' state, this drops the rest of the history table * - the very same number that result i

()

     * @private
     */
    _historyTableAdd() {
        //TODO Add a `this.settings.saveSelectionsIntoHistory` option to prevent saving the selections (in order to gain performance)
        const isEmptyHistoryTable = this.historyTable.length === 0;
        // Only add a new value if it's different from the previous one (to prevent infinitely adding values on mouseover for instance)
        if (isEmptyHistoryTable || this.rawValue !== this._historyTableCurrentValueUsed()) {
            // Trim the history table if the user changed the value of an intermediary state
            let addNewHistoryState = true;
            if (!isEmptyHistoryTable) {
                // If some undo has been done and the user type the exact same data than the next entry after the current history pointer, do not drop the rest of the 'redo' list, and just advance the historyTableIndex
                const nextHistoryStateIndex = this.historyTableIndex + 1;
                if (nextHistoryStateIndex < this.historyTable.length && this.rawValue === this.historyTable[nextHistoryStateIndex].value) {
                    // If the character input result in the same state as the next one, do not remove the next history states nor add a new one
                    addNewHistoryState = false;
                } else {
                    // First remove anything that is after the current index
                    AutoNumericHelper.arrayTrim(this.historyTable, this.historyTableIndex + 1);
                }
            }

            // Update the history pointer
            this.historyTableIndex++;

            // Add the new history state, if needed
            if (addNewHistoryState) {
                // Save the selection info
                const selection = AutoNumericHelper.getElementSelection(this.domElement);
                this.selectionStart = selection.start;
                this.selectionEnd = selection.end;

                // Then add the new raw value
                this.historyTable.push({
                    // Save the rawValue and selection start/end
                    value: this.rawValue,
                    // The selection for this element is temporary, and will be updated when the next history state will be recorded.
                    // That way, we are always sure we save the last caret or selection positions just before the value is changed. Otherwise, we would only save those positions when the value is first changed, and would not take into account that the user could move the caret around afterward.
                    // For instance, this is needed if the user change the element value, and immediately undo it ; if he then does a redo, he'll see the value and the right selection
                    // To sum up; The selection position are not always +1 character, since it could also be '2' if a group separator is added when entering one character. That's why the current history state caret/selection position is updated on each `keyup` event.
                    start: this.selectionStart + 1, // Here we add one since the user added one character too
                    end  : this.selectionEnd + 1,
                });

                // Update the selection in the previous entry, in order to keep track of the updated caret/selection positions
                if (this.historyTable.length > 1) {
                    this.historyTable[this.historyTableIndex - 1].start = this.selectionStart;
                    this.historyTable[this.historyTableIndex - 1].end = this.selectionEnd;
                }
            }

            // Limit the history table size according to the `historySize` option
            if (this.historyTable.length > this.settings.historySize) {
                this._historyTableForget();
            }
        }
    }

    /**
     * Debug function for the history table