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impress/app/assets/javascripts/lib/idiomorph.js

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// https://raw.githubusercontent.com/bigskysoftware/idiomorph/v0.3.0/dist/idiomorph.js
// base IIFE to define idiomorph
var Idiomorph = (function () {
'use strict';
//=============================================================================
// AND NOW IT BEGINS...
//=============================================================================
let EMPTY_SET = new Set();
// default configuration values, updatable by users now
let defaults = {
morphStyle: "outerHTML",
callbacks : {
beforeNodeAdded: noOp,
afterNodeAdded: noOp,
beforeNodeMorphed: noOp,
afterNodeMorphed: noOp,
beforeNodeRemoved: noOp,
afterNodeRemoved: noOp,
beforeAttributeUpdated: noOp,
},
head: {
style: 'merge',
shouldPreserve: function (elt) {
return elt.getAttribute("im-preserve") === "true";
},
shouldReAppend: function (elt) {
return elt.getAttribute("im-re-append") === "true";
},
shouldRemove: noOp,
afterHeadMorphed: noOp,
}
};
//=============================================================================
// Core Morphing Algorithm - morph, morphNormalizedContent, morphOldNodeTo, morphChildren
//=============================================================================
function morph(oldNode, newContent, config = {}) {
if (oldNode instanceof Document) {
oldNode = oldNode.documentElement;
}
if (typeof newContent === 'string') {
newContent = parseContent(newContent);
}
let normalizedContent = normalizeContent(newContent);
let ctx = createMorphContext(oldNode, normalizedContent, config);
return morphNormalizedContent(oldNode, normalizedContent, ctx);
}
function morphNormalizedContent(oldNode, normalizedNewContent, ctx) {
if (ctx.head.block) {
let oldHead = oldNode.querySelector('head');
let newHead = normalizedNewContent.querySelector('head');
if (oldHead && newHead) {
let promises = handleHeadElement(newHead, oldHead, ctx);
// when head promises resolve, call morph again, ignoring the head tag
Promise.all(promises).then(function () {
morphNormalizedContent(oldNode, normalizedNewContent, Object.assign(ctx, {
head: {
block: false,
ignore: true
}
}));
});
return;
}
}
if (ctx.morphStyle === "innerHTML") {
// innerHTML, so we are only updating the children
morphChildren(normalizedNewContent, oldNode, ctx);
return oldNode.children;
} else if (ctx.morphStyle === "outerHTML" || ctx.morphStyle == null) {
// otherwise find the best element match in the new content, morph that, and merge its siblings
// into either side of the best match
let bestMatch = findBestNodeMatch(normalizedNewContent, oldNode, ctx);
// stash the siblings that will need to be inserted on either side of the best match
let previousSibling = bestMatch?.previousSibling;
let nextSibling = bestMatch?.nextSibling;
// morph it
let morphedNode = morphOldNodeTo(oldNode, bestMatch, ctx);
if (bestMatch) {
// if there was a best match, merge the siblings in too and return the
// whole bunch
return insertSiblings(previousSibling, morphedNode, nextSibling);
} else {
// otherwise nothing was added to the DOM
return []
}
} else {
throw "Do not understand how to morph style " + ctx.morphStyle;
}
}
/**
* @param possibleActiveElement
* @param ctx
* @returns {boolean}
*/
function ignoreValueOfActiveElement(possibleActiveElement, ctx) {
return ctx.ignoreActiveValue && possibleActiveElement === document.activeElement;
}
/**
* @param oldNode root node to merge content into
* @param newContent new content to merge
* @param ctx the merge context
* @returns {Element} the element that ended up in the DOM
*/
function morphOldNodeTo(oldNode, newContent, ctx) {
if (ctx.ignoreActive && oldNode === document.activeElement) {
// don't morph focused element
} else if (newContent == null) {
if (ctx.callbacks.beforeNodeRemoved(oldNode) === false) return oldNode;
oldNode.remove();
ctx.callbacks.afterNodeRemoved(oldNode);
return null;
} else if (!isSoftMatch(oldNode, newContent)) {
if (ctx.callbacks.beforeNodeRemoved(oldNode) === false) return oldNode;
if (ctx.callbacks.beforeNodeAdded(newContent) === false) return oldNode;
oldNode.parentElement.replaceChild(newContent, oldNode);
ctx.callbacks.afterNodeAdded(newContent);
ctx.callbacks.afterNodeRemoved(oldNode);
return newContent;
} else {
if (ctx.callbacks.beforeNodeMorphed(oldNode, newContent) === false) return oldNode;
if (oldNode instanceof HTMLHeadElement && ctx.head.ignore) {
// ignore the head element
} else if (oldNode instanceof HTMLHeadElement && ctx.head.style !== "morph") {
handleHeadElement(newContent, oldNode, ctx);
} else {
syncNodeFrom(newContent, oldNode, ctx);
if (!ignoreValueOfActiveElement(oldNode, ctx)) {
morphChildren(newContent, oldNode, ctx);
}
}
ctx.callbacks.afterNodeMorphed(oldNode, newContent);
return oldNode;
}
}
/**
* This is the core algorithm for matching up children. The idea is to use id sets to try to match up
* nodes as faithfully as possible. We greedily match, which allows us to keep the algorithm fast, but
* by using id sets, we are able to better match up with content deeper in the DOM.
*
* Basic algorithm is, for each node in the new content:
*
* - if we have reached the end of the old parent, append the new content
* - if the new content has an id set match with the current insertion point, morph
* - search for an id set match
* - if id set match found, morph
* - otherwise search for a "soft" match
* - if a soft match is found, morph
* - otherwise, prepend the new node before the current insertion point
*
* The two search algorithms terminate if competing node matches appear to outweigh what can be achieved
* with the current node. See findIdSetMatch() and findSoftMatch() for details.
*
* @param {Element} newParent the parent element of the new content
* @param {Element } oldParent the old content that we are merging the new content into
* @param ctx the merge context
*/
function morphChildren(newParent, oldParent, ctx) {
let nextNewChild = newParent.firstChild;
let insertionPoint = oldParent.firstChild;
let newChild;
// run through all the new content
while (nextNewChild) {
newChild = nextNewChild;
nextNewChild = newChild.nextSibling;
// if we are at the end of the exiting parent's children, just append
if (insertionPoint == null) {
if (ctx.callbacks.beforeNodeAdded(newChild) === false) return;
oldParent.appendChild(newChild);
ctx.callbacks.afterNodeAdded(newChild);
removeIdsFromConsideration(ctx, newChild);
continue;
}
// if the current node has an id set match then morph
if (isIdSetMatch(newChild, insertionPoint, ctx)) {
morphOldNodeTo(insertionPoint, newChild, ctx);
insertionPoint = insertionPoint.nextSibling;
removeIdsFromConsideration(ctx, newChild);
continue;
}
// otherwise search forward in the existing old children for an id set match
let idSetMatch = findIdSetMatch(newParent, oldParent, newChild, insertionPoint, ctx);
// if we found a potential match, remove the nodes until that point and morph
if (idSetMatch) {
insertionPoint = removeNodesBetween(insertionPoint, idSetMatch, ctx);
morphOldNodeTo(idSetMatch, newChild, ctx);
removeIdsFromConsideration(ctx, newChild);
continue;
}
// no id set match found, so scan forward for a soft match for the current node
let softMatch = findSoftMatch(newParent, oldParent, newChild, insertionPoint, ctx);
// if we found a soft match for the current node, morph
if (softMatch) {
insertionPoint = removeNodesBetween(insertionPoint, softMatch, ctx);
morphOldNodeTo(softMatch, newChild, ctx);
removeIdsFromConsideration(ctx, newChild);
continue;
}
// abandon all hope of morphing, just insert the new child before the insertion point
// and move on
if (ctx.callbacks.beforeNodeAdded(newChild) === false) return;
oldParent.insertBefore(newChild, insertionPoint);
ctx.callbacks.afterNodeAdded(newChild);
removeIdsFromConsideration(ctx, newChild);
}
// remove any remaining old nodes that didn't match up with new content
while (insertionPoint !== null) {
let tempNode = insertionPoint;
insertionPoint = insertionPoint.nextSibling;
removeNode(tempNode, ctx);
}
}
//=============================================================================
// Attribute Syncing Code
//=============================================================================
/**
* @param attr {String} the attribute to be mutated
* @param to {Element} the element that is going to be updated
* @param updateType {("update"|"remove")}
* @param ctx the merge context
* @returns {boolean} true if the attribute should be ignored, false otherwise
*/
function ignoreAttribute(attr, to, updateType, ctx) {
if(attr === 'value' && ctx.ignoreActiveValue && to === document.activeElement){
return true;
}
return ctx.callbacks.beforeAttributeUpdated(attr, to, updateType) === false;
}
/**
* syncs a given node with another node, copying over all attributes and
* inner element state from the 'from' node to the 'to' node
*
* @param {Element} from the element to copy attributes & state from
* @param {Element} to the element to copy attributes & state to
* @param ctx the merge context
*/
function syncNodeFrom(from, to, ctx) {
let type = from.nodeType
// if is an element type, sync the attributes from the
// new node into the new node
if (type === 1 /* element type */) {
const fromAttributes = from.attributes;
const toAttributes = to.attributes;
for (const fromAttribute of fromAttributes) {
if (ignoreAttribute(fromAttribute.name, to, 'update', ctx)) {
continue;
}
if (to.getAttribute(fromAttribute.name) !== fromAttribute.value) {
to.setAttribute(fromAttribute.name, fromAttribute.value);
}
}
// iterate backwards to avoid skipping over items when a delete occurs
for (let i = toAttributes.length - 1; 0 <= i; i--) {
const toAttribute = toAttributes[i];
if (ignoreAttribute(toAttribute.name, to, 'remove', ctx)) {
continue;
}
if (!from.hasAttribute(toAttribute.name)) {
to.removeAttribute(toAttribute.name);
}
}
}
// sync text nodes
if (type === 8 /* comment */ || type === 3 /* text */) {
if (to.nodeValue !== from.nodeValue) {
to.nodeValue = from.nodeValue;
}
}
if (!ignoreValueOfActiveElement(to, ctx)) {
// sync input values
syncInputValue(from, to, ctx);
}
}
/**
* @param from {Element} element to sync the value from
* @param to {Element} element to sync the value to
* @param attributeName {String} the attribute name
* @param ctx the merge context
*/
function syncBooleanAttribute(from, to, attributeName, ctx) {
if (from[attributeName] !== to[attributeName]) {
let ignoreUpdate = ignoreAttribute(attributeName, to, 'update', ctx);
if (!ignoreUpdate) {
to[attributeName] = from[attributeName];
}
if (from[attributeName]) {
if (!ignoreUpdate) {
to.setAttribute(attributeName, from[attributeName]);
}
} else {
if (!ignoreAttribute(attributeName, to, 'remove', ctx)) {
to.removeAttribute(attributeName);
}
}
}
}
/**
* NB: many bothans died to bring us information:
*
* https://github.com/patrick-steele-idem/morphdom/blob/master/src/specialElHandlers.js
* https://github.com/choojs/nanomorph/blob/master/lib/morph.jsL113
*
* @param from {Element} the element to sync the input value from
* @param to {Element} the element to sync the input value to
* @param ctx the merge context
*/
function syncInputValue(from, to, ctx) {
if (from instanceof HTMLInputElement &&
to instanceof HTMLInputElement &&
from.type !== 'file') {
let fromValue = from.value;
let toValue = to.value;
// sync boolean attributes
syncBooleanAttribute(from, to, 'checked', ctx);
syncBooleanAttribute(from, to, 'disabled', ctx);
if (!from.hasAttribute('value')) {
if (!ignoreAttribute('value', to, 'remove', ctx)) {
to.value = '';
to.removeAttribute('value');
}
} else if (fromValue !== toValue) {
if (!ignoreAttribute('value', to, 'update', ctx)) {
to.setAttribute('value', fromValue);
to.value = fromValue;
}
}
} else if (from instanceof HTMLOptionElement) {
syncBooleanAttribute(from, to, 'selected', ctx)
} else if (from instanceof HTMLTextAreaElement && to instanceof HTMLTextAreaElement) {
let fromValue = from.value;
let toValue = to.value;
if (ignoreAttribute('value', to, 'update', ctx)) {
return;
}
if (fromValue !== toValue) {
to.value = fromValue;
}
if (to.firstChild && to.firstChild.nodeValue !== fromValue) {
to.firstChild.nodeValue = fromValue
}
}
}
//=============================================================================
// the HEAD tag can be handled specially, either w/ a 'merge' or 'append' style
//=============================================================================
function handleHeadElement(newHeadTag, currentHead, ctx) {
let added = []
let removed = []
let preserved = []
let nodesToAppend = []
let headMergeStyle = ctx.head.style;
// put all new head elements into a Map, by their outerHTML
let srcToNewHeadNodes = new Map();
for (const newHeadChild of newHeadTag.children) {
srcToNewHeadNodes.set(newHeadChild.outerHTML, newHeadChild);
}
// for each elt in the current head
for (const currentHeadElt of currentHead.children) {
// If the current head element is in the map
let inNewContent = srcToNewHeadNodes.has(currentHeadElt.outerHTML);
let isReAppended = ctx.head.shouldReAppend(currentHeadElt);
let isPreserved = ctx.head.shouldPreserve(currentHeadElt);
if (inNewContent || isPreserved) {
if (isReAppended) {
// remove the current version and let the new version replace it and re-execute
removed.push(currentHeadElt);
} else {
// this element already exists and should not be re-appended, so remove it from
// the new content map, preserving it in the DOM
srcToNewHeadNodes.delete(currentHeadElt.outerHTML);
preserved.push(currentHeadElt);
}
} else {
if (headMergeStyle === "append") {
// we are appending and this existing element is not new content
// so if and only if it is marked for re-append do we do anything
if (isReAppended) {
removed.push(currentHeadElt);
nodesToAppend.push(currentHeadElt);
}
} else {
// if this is a merge, we remove this content since it is not in the new head
if (ctx.head.shouldRemove(currentHeadElt) !== false) {
removed.push(currentHeadElt);
}
}
}
}
// Push the remaining new head elements in the Map into the
// nodes to append to the head tag
nodesToAppend.push(...srcToNewHeadNodes.values());
log("to append: ", nodesToAppend);
let promises = [];
for (const newNode of nodesToAppend) {
log("adding: ", newNode);
let newElt = document.createRange().createContextualFragment(newNode.outerHTML).firstChild;
log(newElt);
if (ctx.callbacks.beforeNodeAdded(newElt) !== false) {
if (newElt.href || newElt.src) {
let resolve = null;
let promise = new Promise(function (_resolve) {
resolve = _resolve;
});
newElt.addEventListener('load', function () {
resolve();
});
promises.push(promise);
}
currentHead.appendChild(newElt);
ctx.callbacks.afterNodeAdded(newElt);
added.push(newElt);
}
}
// remove all removed elements, after we have appended the new elements to avoid
// additional network requests for things like style sheets
for (const removedElement of removed) {
if (ctx.callbacks.beforeNodeRemoved(removedElement) !== false) {
currentHead.removeChild(removedElement);
ctx.callbacks.afterNodeRemoved(removedElement);
}
}
ctx.head.afterHeadMorphed(currentHead, {added: added, kept: preserved, removed: removed});
return promises;
}
//=============================================================================
// Misc
//=============================================================================
function log() {
//console.log(arguments);
}
function noOp() {
}
/*
Deep merges the config object and the Idiomoroph.defaults object to
produce a final configuration object
*/
function mergeDefaults(config) {
let finalConfig = {};
// copy top level stuff into final config
Object.assign(finalConfig, defaults);
Object.assign(finalConfig, config);
// copy callbacks into final config (do this to deep merge the callbacks)
finalConfig.callbacks = {};
Object.assign(finalConfig.callbacks, defaults.callbacks);
Object.assign(finalConfig.callbacks, config.callbacks);
// copy head config into final config (do this to deep merge the head)
finalConfig.head = {};
Object.assign(finalConfig.head, defaults.head);
Object.assign(finalConfig.head, config.head);
return finalConfig;
}
function createMorphContext(oldNode, newContent, config) {
config = mergeDefaults(config);
return {
target: oldNode,
newContent: newContent,
config: config,
morphStyle: config.morphStyle,
ignoreActive: config.ignoreActive,
ignoreActiveValue: config.ignoreActiveValue,
idMap: createIdMap(oldNode, newContent),
deadIds: new Set(),
callbacks: config.callbacks,
head: config.head
}
}
function isIdSetMatch(node1, node2, ctx) {
if (node1 == null || node2 == null) {
return false;
}
if (node1.nodeType === node2.nodeType && node1.tagName === node2.tagName) {
if (node1.id !== "" && node1.id === node2.id) {
return true;
} else {
return getIdIntersectionCount(ctx, node1, node2) > 0;
}
}
return false;
}
function isSoftMatch(node1, node2) {
if (node1 == null || node2 == null) {
return false;
}
return node1.nodeType === node2.nodeType && node1.tagName === node2.tagName
}
function removeNodesBetween(startInclusive, endExclusive, ctx) {
while (startInclusive !== endExclusive) {
let tempNode = startInclusive;
startInclusive = startInclusive.nextSibling;
removeNode(tempNode, ctx);
}
removeIdsFromConsideration(ctx, endExclusive);
return endExclusive.nextSibling;
}
//=============================================================================
// Scans forward from the insertionPoint in the old parent looking for a potential id match
// for the newChild. We stop if we find a potential id match for the new child OR
// if the number of potential id matches we are discarding is greater than the
// potential id matches for the new child
//=============================================================================
function findIdSetMatch(newContent, oldParent, newChild, insertionPoint, ctx) {
// max id matches we are willing to discard in our search
let newChildPotentialIdCount = getIdIntersectionCount(ctx, newChild, oldParent);
let potentialMatch = null;
// only search forward if there is a possibility of an id match
if (newChildPotentialIdCount > 0) {
let potentialMatch = insertionPoint;
// if there is a possibility of an id match, scan forward
// keep track of the potential id match count we are discarding (the
// newChildPotentialIdCount must be greater than this to make it likely
// worth it)
let otherMatchCount = 0;
while (potentialMatch != null) {
// If we have an id match, return the current potential match
if (isIdSetMatch(newChild, potentialMatch, ctx)) {
return potentialMatch;
}
// computer the other potential matches of this new content
otherMatchCount += getIdIntersectionCount(ctx, potentialMatch, newContent);
if (otherMatchCount > newChildPotentialIdCount) {
// if we have more potential id matches in _other_ content, we
// do not have a good candidate for an id match, so return null
return null;
}
// advanced to the next old content child
potentialMatch = potentialMatch.nextSibling;
}
}
return potentialMatch;
}
//=============================================================================
// Scans forward from the insertionPoint in the old parent looking for a potential soft match
// for the newChild. We stop if we find a potential soft match for the new child OR
// if we find a potential id match in the old parents children OR if we find two
// potential soft matches for the next two pieces of new content
//=============================================================================
function findSoftMatch(newContent, oldParent, newChild, insertionPoint, ctx) {
let potentialSoftMatch = insertionPoint;
let nextSibling = newChild.nextSibling;
let siblingSoftMatchCount = 0;
while (potentialSoftMatch != null) {
if (getIdIntersectionCount(ctx, potentialSoftMatch, newContent) > 0) {
// the current potential soft match has a potential id set match with the remaining new
// content so bail out of looking
return null;
}
// if we have a soft match with the current node, return it
if (isSoftMatch(newChild, potentialSoftMatch)) {
return potentialSoftMatch;
}
if (isSoftMatch(nextSibling, potentialSoftMatch)) {
// the next new node has a soft match with this node, so
// increment the count of future soft matches
siblingSoftMatchCount++;
nextSibling = nextSibling.nextSibling;
// If there are two future soft matches, bail to allow the siblings to soft match
// so that we don't consume future soft matches for the sake of the current node
if (siblingSoftMatchCount >= 2) {
return null;
}
}
// advanced to the next old content child
potentialSoftMatch = potentialSoftMatch.nextSibling;
}
return potentialSoftMatch;
}
function parseContent(newContent) {
let parser = new DOMParser();
// remove svgs to avoid false-positive matches on head, etc.
let contentWithSvgsRemoved = newContent.replace(/<svg(\s[^>]*>|>)([\s\S]*?)<\/svg>/gim, '');
// if the newContent contains a html, head or body tag, we can simply parse it w/o wrapping
if (contentWithSvgsRemoved.match(/<\/html>/) || contentWithSvgsRemoved.match(/<\/head>/) || contentWithSvgsRemoved.match(/<\/body>/)) {
let content = parser.parseFromString(newContent, "text/html");
// if it is a full HTML document, return the document itself as the parent container
if (contentWithSvgsRemoved.match(/<\/html>/)) {
content.generatedByIdiomorph = true;
return content;
} else {
// otherwise return the html element as the parent container
let htmlElement = content.firstChild;
if (htmlElement) {
htmlElement.generatedByIdiomorph = true;
return htmlElement;
} else {
return null;
}
}
} else {
// if it is partial HTML, wrap it in a template tag to provide a parent element and also to help
// deal with touchy tags like tr, tbody, etc.
let responseDoc = parser.parseFromString("<body><template>" + newContent + "</template></body>", "text/html");
let content = responseDoc.body.querySelector('template').content;
content.generatedByIdiomorph = true;
return content
}
}
function normalizeContent(newContent) {
if (newContent == null) {
// noinspection UnnecessaryLocalVariableJS
const dummyParent = document.createElement('div');
return dummyParent;
} else if (newContent.generatedByIdiomorph) {
// the template tag created by idiomorph parsing can serve as a dummy parent
return newContent;
} else if (newContent instanceof Node) {
// a single node is added as a child to a dummy parent
const dummyParent = document.createElement('div');
dummyParent.append(newContent);
return dummyParent;
} else {
// all nodes in the array or HTMLElement collection are consolidated under
// a single dummy parent element
const dummyParent = document.createElement('div');
for (const elt of [...newContent]) {
dummyParent.append(elt);
}
return dummyParent;
}
}
function insertSiblings(previousSibling, morphedNode, nextSibling) {
let stack = []
let added = []
while (previousSibling != null) {
stack.push(previousSibling);
previousSibling = previousSibling.previousSibling;
}
while (stack.length > 0) {
let node = stack.pop();
added.push(node); // push added preceding siblings on in order and insert
morphedNode.parentElement.insertBefore(node, morphedNode);
}
added.push(morphedNode);
while (nextSibling != null) {
stack.push(nextSibling);
added.push(nextSibling); // here we are going in order, so push on as we scan, rather than add
nextSibling = nextSibling.nextSibling;
}
while (stack.length > 0) {
morphedNode.parentElement.insertBefore(stack.pop(), morphedNode.nextSibling);
}
return added;
}
function findBestNodeMatch(newContent, oldNode, ctx) {
let currentElement;
currentElement = newContent.firstChild;
let bestElement = currentElement;
let score = 0;
while (currentElement) {
let newScore = scoreElement(currentElement, oldNode, ctx);
if (newScore > score) {
bestElement = currentElement;
score = newScore;
}
currentElement = currentElement.nextSibling;
}
return bestElement;
}
function scoreElement(node1, node2, ctx) {
if (isSoftMatch(node1, node2)) {
return .5 + getIdIntersectionCount(ctx, node1, node2);
}
return 0;
}
function removeNode(tempNode, ctx) {
removeIdsFromConsideration(ctx, tempNode)
if (ctx.callbacks.beforeNodeRemoved(tempNode) === false) return;
tempNode.remove();
ctx.callbacks.afterNodeRemoved(tempNode);
}
//=============================================================================
// ID Set Functions
//=============================================================================
function isIdInConsideration(ctx, id) {
return !ctx.deadIds.has(id);
}
function idIsWithinNode(ctx, id, targetNode) {
let idSet = ctx.idMap.get(targetNode) || EMPTY_SET;
return idSet.has(id);
}
function removeIdsFromConsideration(ctx, node) {
let idSet = ctx.idMap.get(node) || EMPTY_SET;
for (const id of idSet) {
ctx.deadIds.add(id);
}
}
function getIdIntersectionCount(ctx, node1, node2) {
let sourceSet = ctx.idMap.get(node1) || EMPTY_SET;
let matchCount = 0;
for (const id of sourceSet) {
// a potential match is an id in the source and potentialIdsSet, but
// that has not already been merged into the DOM
if (isIdInConsideration(ctx, id) && idIsWithinNode(ctx, id, node2)) {
++matchCount;
}
}
return matchCount;
}
/**
* A bottom up algorithm that finds all elements with ids inside of the node
* argument and populates id sets for those nodes and all their parents, generating
* a set of ids contained within all nodes for the entire hierarchy in the DOM
*
* @param node {Element}
* @param {Map<Node, Set<String>>} idMap
*/
function populateIdMapForNode(node, idMap) {
let nodeParent = node.parentElement;
// find all elements with an id property
let idElements = node.querySelectorAll('[id]');
for (const elt of idElements) {
let current = elt;
// walk up the parent hierarchy of that element, adding the id
// of element to the parent's id set
while (current !== nodeParent && current != null) {
let idSet = idMap.get(current);
// if the id set doesn't exist, create it and insert it in the map
if (idSet == null) {
idSet = new Set();
idMap.set(current, idSet);
}
idSet.add(elt.id);
current = current.parentElement;
}
}
}
/**
* This function computes a map of nodes to all ids contained within that node (inclusive of the
* node). This map can be used to ask if two nodes have intersecting sets of ids, which allows
* for a looser definition of "matching" than tradition id matching, and allows child nodes
* to contribute to a parent nodes matching.
*
* @param {Element} oldContent the old content that will be morphed
* @param {Element} newContent the new content to morph to
* @returns {Map<Node, Set<String>>} a map of nodes to id sets for the
*/
function createIdMap(oldContent, newContent) {
let idMap = new Map();
populateIdMapForNode(oldContent, idMap);
populateIdMapForNode(newContent, idMap);
return idMap;
}
//=============================================================================
// This is what ends up becoming the Idiomorph global object
//=============================================================================
return {
morph,
defaults
}
})();