src/core/core.datasetController.js
import Animations from './core.animations.js';
import defaults from './core.defaults.js';
import {isArray, isFinite, isObject, valueOrDefault, resolveObjectKey, defined} from '../helpers/helpers.core.js';
import {listenArrayEvents, unlistenArrayEvents} from '../helpers/helpers.collection.js';
import {createContext, sign} from '../helpers/index.js';
/**
* @typedef { import('./core.controller.js').default } Chart
* @typedef { import('./core.scale.js').default } Scale
*/
function scaleClip(scale, allowedOverflow) {
const opts = scale && scale.options || {};
const reverse = opts.reverse;
const min = opts.min === undefined ? allowedOverflow : 0;
const max = opts.max === undefined ? allowedOverflow : 0;
return {
start: reverse ? max : min,
end: reverse ? min : max
};
}
function defaultClip(xScale, yScale, allowedOverflow) {
if (allowedOverflow === false) {
return false;
}
const x = scaleClip(xScale, allowedOverflow);
const y = scaleClip(yScale, allowedOverflow);
return {
top: y.end,
right: x.end,
bottom: y.start,
left: x.start
};
}
function toClip(value) {
let t, r, b, l;
if (isObject(value)) {
t = value.top;
r = value.right;
b = value.bottom;
l = value.left;
} else {
t = r = b = l = value;
}
return {
top: t,
right: r,
bottom: b,
left: l,
disabled: value === false
};
}
function getSortedDatasetIndices(chart, filterVisible) {
const keys = [];
const metasets = chart._getSortedDatasetMetas(filterVisible);
let i, ilen;
for (i = 0, ilen = metasets.length; i < ilen; ++i) {
keys.push(metasets[i].index);
}
return keys;
}
function applyStack(stack, value, dsIndex, options = {}) {
const keys = stack.keys;
const singleMode = options.mode === 'single';
let i, ilen, datasetIndex, otherValue;
if (value === null) {
return;
}
for (i = 0, ilen = keys.length; i < ilen; ++i) {
datasetIndex = +keys[i];
if (datasetIndex === dsIndex) {
if (options.all) {
continue;
}
break;
}
otherValue = stack.values[datasetIndex];
if (isFinite(otherValue) && (singleMode || (value === 0 || sign(value) === sign(otherValue)))) {
value += otherValue;
}
}
return value;
}
function convertObjectDataToArray(data) {
const keys = Object.keys(data);
const adata = new Array(keys.length);
let i, ilen, key;
for (i = 0, ilen = keys.length; i < ilen; ++i) {
key = keys[i];
adata[i] = {
x: key,
y: data[key]
};
}
return adata;
}
function isStacked(scale, meta) {
const stacked = scale && scale.options.stacked;
return stacked || (stacked === undefined && meta.stack !== undefined);
}
function getStackKey(indexScale, valueScale, meta) {
return `${indexScale.id}.${valueScale.id}.${meta.stack || meta.type}`;
}
function getUserBounds(scale) {
const {min, max, minDefined, maxDefined} = scale.getUserBounds();
return {
min: minDefined ? min : Number.NEGATIVE_INFINITY,
max: maxDefined ? max : Number.POSITIVE_INFINITY
};
}
function getOrCreateStack(stacks, stackKey, indexValue) {
const subStack = stacks[stackKey] || (stacks[stackKey] = {});
return subStack[indexValue] || (subStack[indexValue] = {});
}
function getLastIndexInStack(stack, vScale, positive, type) {
for (const meta of vScale.getMatchingVisibleMetas(type).reverse()) {
const value = stack[meta.index];
if ((positive && value > 0) || (!positive && value < 0)) {
return meta.index;
}
}
return null;
}
function updateStacks(controller, parsed) {
const {chart, _cachedMeta: meta} = controller;
const stacks = chart._stacks || (chart._stacks = {}); // map structure is {stackKey: {datasetIndex: value}}
const {iScale, vScale, index: datasetIndex} = meta;
const iAxis = iScale.axis;
const vAxis = vScale.axis;
const key = getStackKey(iScale, vScale, meta);
const ilen = parsed.length;
let stack;
for (let i = 0; i < ilen; ++i) {
const item = parsed[i];
const {[iAxis]: index, [vAxis]: value} = item;
const itemStacks = item._stacks || (item._stacks = {});
stack = itemStacks[vAxis] = getOrCreateStack(stacks, key, index);
stack[datasetIndex] = value;
stack._top = getLastIndexInStack(stack, vScale, true, meta.type);
stack._bottom = getLastIndexInStack(stack, vScale, false, meta.type);
const visualValues = stack._visualValues || (stack._visualValues = {});
visualValues[datasetIndex] = value;
}
}
function getFirstScaleId(chart, axis) {
const scales = chart.scales;
return Object.keys(scales).filter(key => scales[key].axis === axis).shift();
}
function createDatasetContext(parent, index) {
return createContext(parent,
{
active: false,
dataset: undefined,
datasetIndex: index,
index,
mode: 'default',
type: 'dataset'
}
);
}
function createDataContext(parent, index, element) {
return createContext(parent, {
active: false,
dataIndex: index,
parsed: undefined,
raw: undefined,
element,
index,
mode: 'default',
type: 'data'
});
}
function clearStacks(meta, items) {
// Not using meta.index here, because it might be already updated if the dataset changed location
const datasetIndex = meta.controller.index;
const axis = meta.vScale && meta.vScale.axis;
if (!axis) {
return;
}
items = items || meta._parsed;
for (const parsed of items) {
const stacks = parsed._stacks;
if (!stacks || stacks[axis] === undefined || stacks[axis][datasetIndex] === undefined) {
return;
}
delete stacks[axis][datasetIndex];
if (stacks[axis]._visualValues !== undefined && stacks[axis]._visualValues[datasetIndex] !== undefined) {
delete stacks[axis]._visualValues[datasetIndex];
}
}
}
const isDirectUpdateMode = (mode) => mode === 'reset' || mode === 'none';
const cloneIfNotShared = (cached, shared) => shared ? cached : Object.assign({}, cached);
const createStack = (canStack, meta, chart) => canStack && !meta.hidden && meta._stacked
&& {keys: getSortedDatasetIndices(chart, true), values: null};
export default class DatasetController {
/**
* @type {any}
*/
static defaults = {};
/**
* Element type used to generate a meta dataset (e.g. Chart.element.LineElement).
*/
static datasetElementType = null;
/**
* Element type used to generate a meta data (e.g. Chart.element.PointElement).
*/
static dataElementType = null;
/**
* @param {Chart} chart
* @param {number} datasetIndex
*/
constructor(chart, datasetIndex) {
this.chart = chart;
this._ctx = chart.ctx;
this.index = datasetIndex;
this._cachedDataOpts = {};
this._cachedMeta = this.getMeta();
this._type = this._cachedMeta.type;
this.options = undefined;
/** @type {boolean | object} */
this._parsing = false;
this._data = undefined;
this._objectData = undefined;
this._sharedOptions = undefined;
this._drawStart = undefined;
this._drawCount = undefined;
this.enableOptionSharing = false;
this.supportsDecimation = false;
this.$context = undefined;
this._syncList = [];
this.datasetElementType = new.target.datasetElementType;
this.dataElementType = new.target.dataElementType;
this.initialize();
}
initialize() {
const meta = this._cachedMeta;
this.configure();
this.linkScales();
meta._stacked = isStacked(meta.vScale, meta);
this.addElements();
if (this.options.fill && !this.chart.isPluginEnabled('filler')) {
console.warn("Tried to use the 'fill' option without the 'Filler' plugin enabled. Please import and register the 'Filler' plugin and make sure it is not disabled in the options");
}
}
updateIndex(datasetIndex) {
if (this.index !== datasetIndex) {
clearStacks(this._cachedMeta);
}
this.index = datasetIndex;
}
linkScales() {
const chart = this.chart;
const meta = this._cachedMeta;
const dataset = this.getDataset();
const chooseId = (axis, x, y, r) => axis === 'x' ? x : axis === 'r' ? r : y;
const xid = meta.xAxisID = valueOrDefault(dataset.xAxisID, getFirstScaleId(chart, 'x'));
const yid = meta.yAxisID = valueOrDefault(dataset.yAxisID, getFirstScaleId(chart, 'y'));
const rid = meta.rAxisID = valueOrDefault(dataset.rAxisID, getFirstScaleId(chart, 'r'));
const indexAxis = meta.indexAxis;
const iid = meta.iAxisID = chooseId(indexAxis, xid, yid, rid);
const vid = meta.vAxisID = chooseId(indexAxis, yid, xid, rid);
meta.xScale = this.getScaleForId(xid);
meta.yScale = this.getScaleForId(yid);
meta.rScale = this.getScaleForId(rid);
meta.iScale = this.getScaleForId(iid);
meta.vScale = this.getScaleForId(vid);
}
getDataset() {
return this.chart.data.datasets[this.index];
}
getMeta() {
return this.chart.getDatasetMeta(this.index);
}
/**
* @param {string} scaleID
* @return {Scale}
*/
getScaleForId(scaleID) {
return this.chart.scales[scaleID];
}
/**
* @private
*/
_getOtherScale(scale) {
const meta = this._cachedMeta;
return scale === meta.iScale
? meta.vScale
: meta.iScale;
}
reset() {
this._update('reset');
}
/**
* @private
*/
_destroy() {
const meta = this._cachedMeta;
if (this._data) {
unlistenArrayEvents(this._data, this);
}
if (meta._stacked) {
clearStacks(meta);
}
}
/**
* @private
*/
_dataCheck() {
const dataset = this.getDataset();
const data = dataset.data || (dataset.data = []);
const _data = this._data;
// In order to correctly handle data addition/deletion animation (and thus simulate
// real-time charts), we need to monitor these data modifications and synchronize
// the internal metadata accordingly.
if (isObject(data)) {
this._data = convertObjectDataToArray(data);
} else if (_data !== data) {
if (_data) {
// This case happens when the user replaced the data array instance.
unlistenArrayEvents(_data, this);
// Discard old parsed data and stacks
const meta = this._cachedMeta;
clearStacks(meta);
meta._parsed = [];
}
if (data && Object.isExtensible(data)) {
listenArrayEvents(data, this);
}
this._syncList = [];
this._data = data;
}
}
addElements() {
const meta = this._cachedMeta;
this._dataCheck();
if (this.datasetElementType) {
meta.dataset = new this.datasetElementType();
}
}
buildOrUpdateElements(resetNewElements) {
const meta = this._cachedMeta;
const dataset = this.getDataset();
let stackChanged = false;
this._dataCheck();
// make sure cached _stacked status is current
const oldStacked = meta._stacked;
meta._stacked = isStacked(meta.vScale, meta);
// detect change in stack option
if (meta.stack !== dataset.stack) {
stackChanged = true;
// remove values from old stack
clearStacks(meta);
meta.stack = dataset.stack;
}
// Re-sync meta data in case the user replaced the data array or if we missed
// any updates and so make sure that we handle number of datapoints changing.
this._resyncElements(resetNewElements);
// if stack changed, update stack values for the whole dataset
if (stackChanged || oldStacked !== meta._stacked) {
updateStacks(this, meta._parsed);
}
}
/**
* Merges user-supplied and default dataset-level options
* @private
*/
configure() {
const config = this.chart.config;
const scopeKeys = config.datasetScopeKeys(this._type);
const scopes = config.getOptionScopes(this.getDataset(), scopeKeys, true);
this.options = config.createResolver(scopes, this.getContext());
this._parsing = this.options.parsing;
this._cachedDataOpts = {};
}
/**
* @param {number} start
* @param {number} count
*/
parse(start, count) {
const {_cachedMeta: meta, _data: data} = this;
const {iScale, _stacked} = meta;
const iAxis = iScale.axis;
let sorted = start === 0 && count === data.length ? true : meta._sorted;
let prev = start > 0 && meta._parsed[start - 1];
let i, cur, parsed;
if (this._parsing === false) {
meta._parsed = data;
meta._sorted = true;
parsed = data;
} else {
if (isArray(data[start])) {
parsed = this.parseArrayData(meta, data, start, count);
} else if (isObject(data[start])) {
parsed = this.parseObjectData(meta, data, start, count);
} else {
parsed = this.parsePrimitiveData(meta, data, start, count);
}
const isNotInOrderComparedToPrev = () => cur[iAxis] === null || (prev && cur[iAxis] < prev[iAxis]);
for (i = 0; i < count; ++i) {
meta._parsed[i + start] = cur = parsed[i];
if (sorted) {
if (isNotInOrderComparedToPrev()) {
sorted = false;
}
prev = cur;
}
}
meta._sorted = sorted;
}
if (_stacked) {
updateStacks(this, parsed);
}
}
/**
* Parse array of primitive values
* @param {object} meta - dataset meta
* @param {array} data - data array. Example [1,3,4]
* @param {number} start - start index
* @param {number} count - number of items to parse
* @returns {object} parsed item - item containing index and a parsed value
* for each scale id.
* Example: {xScale0: 0, yScale0: 1}
* @protected
*/
parsePrimitiveData(meta, data, start, count) {
const {iScale, vScale} = meta;
const iAxis = iScale.axis;
const vAxis = vScale.axis;
const labels = iScale.getLabels();
const singleScale = iScale === vScale;
const parsed = new Array(count);
let i, ilen, index;
for (i = 0, ilen = count; i < ilen; ++i) {
index = i + start;
parsed[i] = {
[iAxis]: singleScale || iScale.parse(labels[index], index),
[vAxis]: vScale.parse(data[index], index)
};
}
return parsed;
}
/**
* Parse array of arrays
* @param {object} meta - dataset meta
* @param {array} data - data array. Example [[1,2],[3,4]]
* @param {number} start - start index
* @param {number} count - number of items to parse
* @returns {object} parsed item - item containing index and a parsed value
* for each scale id.
* Example: {x: 0, y: 1}
* @protected
*/
parseArrayData(meta, data, start, count) {
const {xScale, yScale} = meta;
const parsed = new Array(count);
let i, ilen, index, item;
for (i = 0, ilen = count; i < ilen; ++i) {
index = i + start;
item = data[index];
parsed[i] = {
x: xScale.parse(item[0], index),
y: yScale.parse(item[1], index)
};
}
return parsed;
}
/**
* Parse array of objects
* @param {object} meta - dataset meta
* @param {array} data - data array. Example [{x:1, y:5}, {x:2, y:10}]
* @param {number} start - start index
* @param {number} count - number of items to parse
* @returns {object} parsed item - item containing index and a parsed value
* for each scale id. _custom is optional
* Example: {xScale0: 0, yScale0: 1, _custom: {r: 10, foo: 'bar'}}
* @protected
*/
parseObjectData(meta, data, start, count) {
const {xScale, yScale} = meta;
const {xAxisKey = 'x', yAxisKey = 'y'} = this._parsing;
const parsed = new Array(count);
let i, ilen, index, item;
for (i = 0, ilen = count; i < ilen; ++i) {
index = i + start;
item = data[index];
parsed[i] = {
x: xScale.parse(resolveObjectKey(item, xAxisKey), index),
y: yScale.parse(resolveObjectKey(item, yAxisKey), index)
};
}
return parsed;
}
/**
* @protected
*/
getParsed(index) {
return this._cachedMeta._parsed[index];
}
/**
* @protected
*/
getDataElement(index) {
return this._cachedMeta.data[index];
}
/**
* @protected
*/
applyStack(scale, parsed, mode) {
const chart = this.chart;
const meta = this._cachedMeta;
const value = parsed[scale.axis];
const stack = {
keys: getSortedDatasetIndices(chart, true),
values: parsed._stacks[scale.axis]._visualValues
};
return applyStack(stack, value, meta.index, {mode});
}
/**
* @protected
*/
updateRangeFromParsed(range, scale, parsed, stack) {
const parsedValue = parsed[scale.axis];
let value = parsedValue === null ? NaN : parsedValue;
const values = stack && parsed._stacks[scale.axis];
if (stack && values) {
stack.values = values;
value = applyStack(stack, parsedValue, this._cachedMeta.index);
}
range.min = Math.min(range.min, value);
range.max = Math.max(range.max, value);
}
/**
* @protected
*/
getMinMax(scale, canStack) {
const meta = this._cachedMeta;
const _parsed = meta._parsed;
const sorted = meta._sorted && scale === meta.iScale;
const ilen = _parsed.length;
const otherScale = this._getOtherScale(scale);
const stack = createStack(canStack, meta, this.chart);
const range = {min: Number.POSITIVE_INFINITY, max: Number.NEGATIVE_INFINITY};
const {min: otherMin, max: otherMax} = getUserBounds(otherScale);
let i, parsed;
function _skip() {
parsed = _parsed[i];
const otherValue = parsed[otherScale.axis];
return !isFinite(parsed[scale.axis]) || otherMin > otherValue || otherMax < otherValue;
}
for (i = 0; i < ilen; ++i) {
if (_skip()) {
continue;
}
this.updateRangeFromParsed(range, scale, parsed, stack);
if (sorted) {
// if the data is sorted, we don't need to check further from this end of array
break;
}
}
if (sorted) {
// in the sorted case, find first non-skipped value from other end of array
for (i = ilen - 1; i >= 0; --i) {
if (_skip()) {
continue;
}
this.updateRangeFromParsed(range, scale, parsed, stack);
break;
}
}
return range;
}
getAllParsedValues(scale) {
const parsed = this._cachedMeta._parsed;
const values = [];
let i, ilen, value;
for (i = 0, ilen = parsed.length; i < ilen; ++i) {
value = parsed[i][scale.axis];
if (isFinite(value)) {
values.push(value);
}
}
return values;
}
/**
* @return {number|boolean}
* @protected
*/
getMaxOverflow() {
return false;
}
/**
* @protected
*/
getLabelAndValue(index) {
const meta = this._cachedMeta;
const iScale = meta.iScale;
const vScale = meta.vScale;
const parsed = this.getParsed(index);
return {
label: iScale ? '' + iScale.getLabelForValue(parsed[iScale.axis]) : '',
value: vScale ? '' + vScale.getLabelForValue(parsed[vScale.axis]) : ''
};
}
/**
* @private
*/
_update(mode) {
const meta = this._cachedMeta;
this.update(mode || 'default');
meta._clip = toClip(valueOrDefault(this.options.clip, defaultClip(meta.xScale, meta.yScale, this.getMaxOverflow())));
}
/**
* @param {string} mode
*/
update(mode) {} // eslint-disable-line no-unused-vars
draw() {
const ctx = this._ctx;
const chart = this.chart;
const meta = this._cachedMeta;
const elements = meta.data || [];
const area = chart.chartArea;
const active = [];
const start = this._drawStart || 0;
const count = this._drawCount || (elements.length - start);
const drawActiveElementsOnTop = this.options.drawActiveElementsOnTop;
let i;
if (meta.dataset) {
meta.dataset.draw(ctx, area, start, count);
}
for (i = start; i < start + count; ++i) {
const element = elements[i];
if (element.hidden) {
continue;
}
if (element.active && drawActiveElementsOnTop) {
active.push(element);
} else {
element.draw(ctx, area);
}
}
for (i = 0; i < active.length; ++i) {
active[i].draw(ctx, area);
}
}
/**
* Returns a set of predefined style properties that should be used to represent the dataset
* or the data if the index is specified
* @param {number} index - data index
* @param {boolean} [active] - true if hover
* @return {object} style object
*/
getStyle(index, active) {
const mode = active ? 'active' : 'default';
return index === undefined && this._cachedMeta.dataset
? this.resolveDatasetElementOptions(mode)
: this.resolveDataElementOptions(index || 0, mode);
}
/**
* @protected
*/
getContext(index, active, mode) {
const dataset = this.getDataset();
let context;
if (index >= 0 && index < this._cachedMeta.data.length) {
const element = this._cachedMeta.data[index];
context = element.$context ||
(element.$context = createDataContext(this.getContext(), index, element));
context.parsed = this.getParsed(index);
context.raw = dataset.data[index];
context.index = context.dataIndex = index;
} else {
context = this.$context ||
(this.$context = createDatasetContext(this.chart.getContext(), this.index));
context.dataset = dataset;
context.index = context.datasetIndex = this.index;
}
context.active = !!active;
context.mode = mode;
return context;
}
/**
* @param {string} [mode]
* @protected
*/
resolveDatasetElementOptions(mode) {
return this._resolveElementOptions(this.datasetElementType.id, mode);
}
/**
* @param {number} index
* @param {string} [mode]
* @protected
*/
resolveDataElementOptions(index, mode) {
return this._resolveElementOptions(this.dataElementType.id, mode, index);
}
/**
* @private
*/
_resolveElementOptions(elementType, mode = 'default', index) {
const active = mode === 'active';
const cache = this._cachedDataOpts;
const cacheKey = elementType + '-' + mode;
const cached = cache[cacheKey];
const sharing = this.enableOptionSharing && defined(index);
if (cached) {
return cloneIfNotShared(cached, sharing);
}
const config = this.chart.config;
const scopeKeys = config.datasetElementScopeKeys(this._type, elementType);
const prefixes = active ? [`${elementType}Hover`, 'hover', elementType, ''] : [elementType, ''];
const scopes = config.getOptionScopes(this.getDataset(), scopeKeys);
const names = Object.keys(defaults.elements[elementType]);
// context is provided as a function, and is called only if needed,
// so we don't create a context for each element if not needed.
const context = () => this.getContext(index, active, mode);
const values = config.resolveNamedOptions(scopes, names, context, prefixes);
if (values.$shared) {
// `$shared` indicates this set of options can be shared between multiple elements.
// Sharing is used to reduce number of properties to change during animation.
values.$shared = sharing;
// We cache options by `mode`, which can be 'active' for example. This enables us
// to have the 'active' element options and 'default' options to switch between
// when interacting.
cache[cacheKey] = Object.freeze(cloneIfNotShared(values, sharing));
}
return values;
}
/**
* @private
*/
_resolveAnimations(index, transition, active) {
const chart = this.chart;
const cache = this._cachedDataOpts;
const cacheKey = `animation-${transition}`;
const cached = cache[cacheKey];
if (cached) {
return cached;
}
let options;
if (chart.options.animation !== false) {
const config = this.chart.config;
const scopeKeys = config.datasetAnimationScopeKeys(this._type, transition);
const scopes = config.getOptionScopes(this.getDataset(), scopeKeys);
options = config.createResolver(scopes, this.getContext(index, active, transition));
}
const animations = new Animations(chart, options && options.animations);
if (options && options._cacheable) {
cache[cacheKey] = Object.freeze(animations);
}
return animations;
}
/**
* Utility for getting the options object shared between elements
* @protected
*/
getSharedOptions(options) {
if (!options.$shared) {
return;
}
return this._sharedOptions || (this._sharedOptions = Object.assign({}, options));
}
/**
* Utility for determining if `options` should be included in the updated properties
* @protected
*/
includeOptions(mode, sharedOptions) {
return !sharedOptions || isDirectUpdateMode(mode) || this.chart._animationsDisabled;
}
/**
* @todo v4, rename to getSharedOptions and remove excess functions
*/
_getSharedOptions(start, mode) {
const firstOpts = this.resolveDataElementOptions(start, mode);
const previouslySharedOptions = this._sharedOptions;
const sharedOptions = this.getSharedOptions(firstOpts);
const includeOptions = this.includeOptions(mode, sharedOptions) || (sharedOptions !== previouslySharedOptions);
this.updateSharedOptions(sharedOptions, mode, firstOpts);
return {sharedOptions, includeOptions};
}
/**
* Utility for updating an element with new properties, using animations when appropriate.
* @protected
*/
updateElement(element, index, properties, mode) {
if (isDirectUpdateMode(mode)) {
Object.assign(element, properties);
} else {
this._resolveAnimations(index, mode).update(element, properties);
}
}
/**
* Utility to animate the shared options, that are potentially affecting multiple elements.
* @protected
*/
updateSharedOptions(sharedOptions, mode, newOptions) {
if (sharedOptions && !isDirectUpdateMode(mode)) {
this._resolveAnimations(undefined, mode).update(sharedOptions, newOptions);
}
}
/**
* @private
*/
_setStyle(element, index, mode, active) {
element.active = active;
const options = this.getStyle(index, active);
this._resolveAnimations(index, mode, active).update(element, {
// When going from active to inactive, we need to update to the shared options.
// This way the once hovered element will end up with the same original shared options instance, after animation.
options: (!active && this.getSharedOptions(options)) || options
});
}
removeHoverStyle(element, datasetIndex, index) {
this._setStyle(element, index, 'active', false);
}
setHoverStyle(element, datasetIndex, index) {
this._setStyle(element, index, 'active', true);
}
/**
* @private
*/
_removeDatasetHoverStyle() {
const element = this._cachedMeta.dataset;
if (element) {
this._setStyle(element, undefined, 'active', false);
}
}
/**
* @private
*/
_setDatasetHoverStyle() {
const element = this._cachedMeta.dataset;
if (element) {
this._setStyle(element, undefined, 'active', true);
}
}
/**
* @private
*/
_resyncElements(resetNewElements) {
const data = this._data;
const elements = this._cachedMeta.data;
// Apply changes detected through array listeners
for (const [method, arg1, arg2] of this._syncList) {
this[method](arg1, arg2);
}
this._syncList = [];
const numMeta = elements.length;
const numData = data.length;
const count = Math.min(numData, numMeta);
if (count) {
// TODO: It is not optimal to always parse the old data
// This is done because we are not detecting direct assignments:
// chart.data.datasets[0].data[5] = 10;
// chart.data.datasets[0].data[5].y = 10;
this.parse(0, count);
}
if (numData > numMeta) {
this._insertElements(numMeta, numData - numMeta, resetNewElements);
} else if (numData < numMeta) {
this._removeElements(numData, numMeta - numData);
}
}
/**
* @private
*/
_insertElements(start, count, resetNewElements = true) {
const meta = this._cachedMeta;
const data = meta.data;
const end = start + count;
let i;
const move = (arr) => {
arr.length += count;
for (i = arr.length - 1; i >= end; i--) {
arr[i] = arr[i - count];
}
};
move(data);
for (i = start; i < end; ++i) {
data[i] = new this.dataElementType();
}
if (this._parsing) {
move(meta._parsed);
}
this.parse(start, count);
if (resetNewElements) {
this.updateElements(data, start, count, 'reset');
}
}
updateElements(element, start, count, mode) {} // eslint-disable-line no-unused-vars
/**
* @private
*/
_removeElements(start, count) {
const meta = this._cachedMeta;
if (this._parsing) {
const removed = meta._parsed.splice(start, count);
if (meta._stacked) {
clearStacks(meta, removed);
}
}
meta.data.splice(start, count);
}
/**
* @private
*/
_sync(args) {
if (this._parsing) {
this._syncList.push(args);
} else {
const [method, arg1, arg2] = args;
this[method](arg1, arg2);
}
this.chart._dataChanges.push([this.index, ...args]);
}
_onDataPush() {
const count = arguments.length;
this._sync(['_insertElements', this.getDataset().data.length - count, count]);
}
_onDataPop() {
this._sync(['_removeElements', this._cachedMeta.data.length - 1, 1]);
}
_onDataShift() {
this._sync(['_removeElements', 0, 1]);
}
_onDataSplice(start, count) {
if (count) {
this._sync(['_removeElements', start, count]);
}
const newCount = arguments.length - 2;
if (newCount) {
this._sync(['_insertElements', start, newCount]);
}
}
_onDataUnshift() {
this._sync(['_insertElements', 0, arguments.length]);
}
}