snappymail/vendors/knockout/src/binding/bindingAttributeSyntax.js
2024-03-04 01:12:40 +01:00

443 lines
21 KiB
JavaScript

// Hide or don't minify context properties, see https://github.com/knockout/knockout/issues/2294
const contextSubscribable = Symbol('_subscribable'),
contextAncestorBindingInfo = Symbol('_ancestorBindingInfo'),
contextDataDependency = Symbol('_dataDependency'),
inheritParentVm = {},
boundElementDomDataKey = ko.utils.domData.nextKey();
ko.bindingHandlers = {};
// The ko.bindingContext constructor is only called directly to create the root context. For child
// contexts, use bindingContext.createChildContext or bindingContext.extend.
ko.bindingContext = class {
constructor(dataItemOrAccessor, parentContext, extendCallback, options)
{
var self = this,
shouldInheritData = dataItemOrAccessor === inheritParentVm,
realDataItemOrAccessor = shouldInheritData ? undefined : dataItemOrAccessor,
isFunc = typeof(realDataItemOrAccessor) == "function" && !ko.isObservable(realDataItemOrAccessor),
subscribable,
dataDependency = options?.['dataDependency'],
// The binding context object includes static properties for the current, parent, and root view models.
// If a view model is actually stored in an observable, the corresponding binding context object, and
// any child contexts, must be updated when the view model is changed.
updateContext = () => {
// Most of the time, the context will directly get a view model object, but if a function is given,
// we call the function to retrieve the view model. If the function accesses any observables or returns
// an observable, the dependency is tracked, and those observables can later cause the binding
// context to be updated.
var dataItemOrObservable = isFunc ? realDataItemOrAccessor() : realDataItemOrAccessor,
dataItem = ko.utils.unwrapObservable(dataItemOrObservable);
if (parentContext) {
// Copy $root and any custom properties from the parent context
ko.utils.extend(self, parentContext);
// Copy Symbol properties
if (contextAncestorBindingInfo in parentContext) {
self[contextAncestorBindingInfo] = parentContext[contextAncestorBindingInfo];
}
} else {
self['$root'] = dataItem;
// Export 'ko' in the binding context so it will be available in bindings and templates
// even if 'ko' isn't exported as a global, such as when using an AMD loader.
// See https://github.com/SteveSanderson/knockout/issues/490
self['ko'] = ko;
}
self[contextSubscribable] = subscribable;
if (shouldInheritData) {
dataItem = self['$data'];
} else {
self['$data'] = dataItem;
}
// The extendCallback function is provided when creating a child context or extending a context.
// It handles the specific actions needed to finish setting up the binding context. Actions in this
// function could also add dependencies to this binding context.
extendCallback?.(self, parentContext, dataItem);
// When a "parent" context is given and we don't already have a dependency on its context, register a dependency on it.
// Thus whenever the parent context is updated, this context will also be updated.
if (parentContext?.[contextSubscribable] && !ko.dependencyDetection.computed().hasAncestorDependency(parentContext[contextSubscribable])) {
parentContext[contextSubscribable]();
}
if (dataDependency) {
self[contextDataDependency] = dataDependency;
}
return self['$data'];
};
if (options?.['exportDependencies']) {
// The "exportDependencies" option means that the calling code will track any dependencies and re-create
// the binding context when they change.
updateContext();
} else {
subscribable = ko.pureComputed(updateContext);
subscribable.peek();
// At this point, the binding context has been initialized, and the "subscribable" computed observable is
// subscribed to any observables that were accessed in the process. If there is nothing to track, the
// computed will be inactive, and we can safely throw it away. If it's active, the computed is stored in
// the context object.
if (subscribable.isActive()) {
// Always notify because even if the model ($data) hasn't changed, other context properties might have changed
subscribable.equalityComparer = null;
} else {
self[contextSubscribable] = undefined;
}
}
}
// Extend the binding context hierarchy with a new view model object. If the parent context is watching
// any observables, the new child context will automatically get a dependency on the parent context.
// But this does not mean that the $data value of the child context will also get updated. If the child
// view model also depends on the parent view model, you must provide a function that returns the correct
// view model on each update.
'createChildContext'(dataItemOrAccessor, options) {
return new ko.bindingContext(dataItemOrAccessor, this, (self, parentContext) => {
// Extend the context hierarchy by setting the appropriate pointers
self['$parent'] = parentContext['$data'];
options['extend']?.(self);
}, options);
}
// Extend the binding context with new custom properties. This doesn't change the context hierarchy.
// Similarly to "child" contexts, provide a function here to make sure that the correct values are set
// when an observable view model is updated.
'extend'(properties, options) {
return new ko.bindingContext(inheritParentVm, this, self =>
ko.utils.extend(self, typeof(properties) == "function" ? properties(self) : properties)
, options);
}
};
function asyncContextDispose(node) {
var bindingInfo = ko.utils.domData.get(node, boundElementDomDataKey),
asyncContext = bindingInfo?.asyncContext;
if (asyncContext) {
bindingInfo.asyncContext = null;
asyncContext.notifyAncestor();
}
}
class AsyncCompleteContext {
constructor(node, bindingInfo, ancestorBindingInfo) {
this.node = node;
this.bindingInfo = bindingInfo;
this.asyncDescendants = new Set;
this.childrenComplete = false;
bindingInfo.asyncContext || ko.utils.domNodeDisposal['addDisposeCallback'](node, asyncContextDispose);
if (ancestorBindingInfo?.asyncContext) {
ancestorBindingInfo.asyncContext.asyncDescendants.add(node);
this.ancestorBindingInfo = ancestorBindingInfo;
}
}
notifyAncestor() {
this.ancestorBindingInfo?.asyncContext?.descendantComplete(this.node);
}
descendantComplete(node) {
this.asyncDescendants.delete(node);
this.asyncDescendants.size || this.completeChildren?.();
}
completeChildren() {
this.childrenComplete = true;
if (this.bindingInfo.asyncContext && !this.asyncDescendants.size) {
this.bindingInfo.asyncContext = null;
ko.utils.domNodeDisposal.removeDisposeCallback(this.node, asyncContextDispose);
ko.bindingEvent.notify(this.node, ko.bindingEvent.descendantsComplete);
this.notifyAncestor();
}
}
}
ko.bindingEvent = {
childrenComplete: "childrenComplete",
descendantsComplete : "descendantsComplete",
subscribe: (node, event, callback, context, options) => {
var bindingInfo = ko.utils.domData.getOrSet(node, boundElementDomDataKey, {});
if (!bindingInfo.eventSubscribable) {
bindingInfo.eventSubscribable = new ko.subscribable;
}
if (options?.['notifyImmediately'] && bindingInfo.notifiedEvents[event]) {
ko.dependencyDetection.ignore(callback, context, [node]);
}
return bindingInfo.eventSubscribable['subscribe'](callback, context, event);
},
notify: (node, event) => {
var bindingInfo = ko.utils.domData.get(node, boundElementDomDataKey);
if (bindingInfo) {
bindingInfo.notifiedEvents[event] = true;
bindingInfo.eventSubscribable?.notifySubscribers(node, event);
if (event == ko.bindingEvent.childrenComplete) {
if (bindingInfo.asyncContext) {
bindingInfo.asyncContext.completeChildren();
} else if (bindingInfo.asyncContext === undefined && bindingInfo.eventSubscribable?.hasSubscriptionsForEvent(ko.bindingEvent.descendantsComplete)) {
// It's currently an error to register a descendantsComplete handler for a node that was never registered as completing asynchronously.
// That's because without the asyncContext, we don't have a way to know that all descendants have completed.
throw Error("descendantsComplete event not supported for bindings on this node");
}
}
}
},
startPossiblyAsyncContentBinding: (node, bindingContext) => {
var bindingInfo = ko.utils.domData.getOrSet(node, boundElementDomDataKey, {});
if (!bindingInfo.asyncContext) {
bindingInfo.asyncContext = new AsyncCompleteContext(node, bindingInfo, bindingContext[contextAncestorBindingInfo]);
}
// If the provided context was already extended with this node's binding info, just return the extended context
if (bindingContext[contextAncestorBindingInfo] == bindingInfo) {
return bindingContext;
}
return bindingContext['extend'](ctx => {
ctx[contextAncestorBindingInfo] = bindingInfo;
});
}
};
function applyBindingsToDescendantsInternal(bindingContext, elementOrVirtualElement) {
var currentChild, nextInQueue = ko.virtualElements.firstChild(elementOrVirtualElement);
while (currentChild = nextInQueue) {
// Keep a record of the next child *before* applying bindings, in case the binding removes the current child from its position
nextInQueue = ko.virtualElements.nextSibling(currentChild);
applyBindingsToNodeAndDescendantsInternal(bindingContext, currentChild);
}
ko.bindingEvent.notify(elementOrVirtualElement, ko.bindingEvent.childrenComplete);
}
function applyBindingsToNodeAndDescendantsInternal(bindingContext, nodeVerified) {
var bindingContextForDescendants = bindingContext;
var isElement = (nodeVerified.nodeType === 1);
// Perf optimisation: Apply bindings only if...
// (1) We need to store the binding info for the node (all element nodes)
// (2) It might have bindings (e.g., it has a data-bind attribute, or it's a marker for a containerless template)
if (isElement || ko.bindingProvider.nodeHasBindings(nodeVerified))
bindingContextForDescendants = applyBindingsToNodeInternal(nodeVerified, null, bindingContext);
// Don't want bindings that operate on text nodes to mutate <script> and <textarea> contents,
// because it's unexpected and a potential XSS issue.
// Also bindings should not operate on <template> elements since this breaks in Internet Explorer
// and because such elements' contents are always intended to be bound in a different context
// from where they appear in the document.
if (bindingContextForDescendants && !nodeVerified.matches?.('SCRIPT,TEXTAREA,TEMPLATE')) {
applyBindingsToDescendantsInternal(bindingContextForDescendants, nodeVerified);
}
}
function topologicalSortBindings(bindings) {
// Depth-first sort
var result = [], // The list of key/handler pairs that we will return
bindingsConsidered = {}, // A temporary record of which bindings are already in 'result'
cyclicDependencyStack = []; // Keeps track of a depth-search so that, if there's a cycle, we know which bindings caused it
ko.utils.objectForEach(bindings, function pushBinding(bindingKey) {
if (!bindingsConsidered[bindingKey]) {
var binding = ko.bindingHandlers[bindingKey];
if (binding) {
// First add dependencies (if any) of the current binding
if (binding['after']) {
cyclicDependencyStack.push(bindingKey);
binding['after'].forEach(bindingDependencyKey => {
if (bindings[bindingDependencyKey]) {
if (cyclicDependencyStack.includes(bindingDependencyKey)) {
throw Error("Cannot combine the following bindings, because they have a cyclic dependency: " + cyclicDependencyStack.join(", "));
}
pushBinding(bindingDependencyKey);
}
});
cyclicDependencyStack.length--;
}
// Next add the current binding
result.push({ key: bindingKey, handler: binding });
}
bindingsConsidered[bindingKey] = true;
}
});
return result;
}
function applyBindingsToNodeInternal(node, sourceBindings, bindingContext) {
var bindingInfo = ko.utils.domData.getOrSet(node, boundElementDomDataKey, {});
// Prevent multiple applyBindings calls for the same node, except when a binding value is specified
var alreadyBound = bindingInfo.alreadyBound;
if (!sourceBindings) {
if (alreadyBound) {
throw Error("You cannot apply bindings multiple times to the same element.");
}
bindingInfo.alreadyBound = true;
}
if (!alreadyBound) {
bindingInfo.context = bindingContext;
}
if (!bindingInfo.notifiedEvents) {
bindingInfo.notifiedEvents = {};
}
// Use bindings if given, otherwise fall back on asking the bindings provider to give us some bindings
var bindings;
if (sourceBindings && typeof sourceBindings !== 'function') {
bindings = sourceBindings;
} else {
// Get the binding from the provider within a computed observable so that we can update the bindings whenever
// the binding context is updated or if the binding provider accesses observables.
var bindingsUpdater = ko.computed(
() => {
bindings = sourceBindings ? sourceBindings(bindingContext, node) : ko.bindingProvider.getBindingAccessors(node, bindingContext);
// Register a dependency on the binding context to support observable view models.
if (bindings) {
bindingContext[contextSubscribable]?.();
bindingContext[contextDataDependency]?.();
}
return bindings;
},
{ disposeWhenNodeIsRemoved: node }
);
if (!bindings || !bindingsUpdater.isActive())
bindingsUpdater = null;
}
var contextToExtend = bindingContext;
var bindingHandlerThatControlsDescendantBindings;
if (bindings) {
// Return the value accessor for a given binding. When bindings are static (won't be updated because of a binding
// context update), just return the value accessor from the binding. Otherwise, return a function that always gets
// the latest binding value and registers a dependency on the binding updater.
var getValueAccessor = bindingsUpdater
? bindingKey => () => bindingsUpdater()[bindingKey]()
: bindingKey => bindings[bindingKey];
// Use of allBindings as a function is deprecated and removed
// The following is the 3.x allBindings API
var allBindings = {
'get': key => bindings[key] && getValueAccessor(key)(),
'has': key => key in bindings
};
if (ko.bindingEvent.childrenComplete in bindings) {
ko.bindingEvent.subscribe(node, ko.bindingEvent.childrenComplete, () => {
var callback = bindings[ko.bindingEvent.childrenComplete]();
if (callback) {
var nodes = ko.virtualElements.childNodes(node);
nodes.length && callback(nodes, ko['dataFor'](nodes[0]));
}
});
}
if (ko.bindingEvent.descendantsComplete in bindings) {
contextToExtend = ko.bindingEvent.startPossiblyAsyncContentBinding(node, bindingContext);
ko.bindingEvent.subscribe(node, ko.bindingEvent.descendantsComplete, () => {
var callback = bindings[ko.bindingEvent.descendantsComplete]();
if (callback && ko.virtualElements.firstChild(node)) {
callback(node);
}
});
}
// First put the bindings into the right order
// Go through the sorted bindings, calling init and update for each
topologicalSortBindings(bindings).forEach(bindingKeyAndHandler => {
// Note that topologicalSortBindings has already filtered out any nonexistent binding handlers,
// so bindingKeyAndHandler.handler will always be nonnull.
var handlerInitFn = bindingKeyAndHandler.handler["init"],
handlerUpdateFn = bindingKeyAndHandler.handler["update"],
bindingKey = bindingKeyAndHandler.key;
// COMMENT_NODE
if (node.nodeType === 8 && !ko.virtualElements.allowedBindings[bindingKey]) {
throw Error("The binding '" + bindingKey + "' cannot be used with comment nodes");
}
try {
// Run init, ignoring any dependencies
if (typeof handlerInitFn == "function") {
ko.dependencyDetection.ignore(() => {
var initResult = handlerInitFn(node, getValueAccessor(bindingKey), allBindings, contextToExtend['$data'], contextToExtend);
// If this binding handler claims to control descendant bindings, make a note of this
if (initResult && initResult['controlsDescendantBindings']) {
if (bindingHandlerThatControlsDescendantBindings !== undefined)
throw Error("Multiple bindings (" + bindingHandlerThatControlsDescendantBindings + " and " + bindingKey + ") are trying to control descendant bindings of the same element. You cannot use these bindings together on the same element.");
bindingHandlerThatControlsDescendantBindings = bindingKey;
}
});
}
// Run update in its own computed wrapper
if (typeof handlerUpdateFn == "function") {
ko.computed(
() => handlerUpdateFn(node, getValueAccessor(bindingKey), allBindings, contextToExtend['$data'], contextToExtend),
{ disposeWhenNodeIsRemoved: node }
);
}
} catch (ex) {
ex.message = "Unable to process binding \"" + bindingKey + ": " + bindings[bindingKey] + "\"\nMessage: " + ex.message;
throw ex;
}
});
}
return bindingHandlerThatControlsDescendantBindings === undefined && contextToExtend;
}
ko.storedBindingContextForNode = node => {
var bindingInfo = ko.utils.domData.get(node, boundElementDomDataKey);
return bindingInfo && bindingInfo.context;
}
function getBindingContext(viewModelOrBindingContext, extendContextCallback) {
return viewModelOrBindingContext && (viewModelOrBindingContext instanceof ko.bindingContext)
? viewModelOrBindingContext
: new ko.bindingContext(viewModelOrBindingContext, null, extendContextCallback);
}
ko['applyBindingAccessorsToNode'] = (node, bindings, viewModelOrBindingContext) =>
applyBindingsToNodeInternal(node, bindings, getBindingContext(viewModelOrBindingContext));
ko.applyBindingsToDescendants = (viewModelOrBindingContext, rootNode) => {
if (rootNode.nodeType === 1 || rootNode.nodeType === 8)
applyBindingsToDescendantsInternal(getBindingContext(viewModelOrBindingContext), rootNode);
};
ko.applyBindings = function (viewModelOrBindingContext, rootNode, extendContextCallback) {
if (arguments.length < 2) {
rootNode = document.body;
if (!rootNode) {
throw Error("ko.applyBindings: could not find document.body; has the document been loaded?");
}
} else if (!rootNode || (rootNode.nodeType !== 1 && rootNode.nodeType !== 8)) {
throw Error("ko.applyBindings: first parameter should be your view model; second parameter should be a DOM node");
}
applyBindingsToNodeAndDescendantsInternal(getBindingContext(viewModelOrBindingContext, extendContextCallback), rootNode);
};
// Retrieving binding context from arbitrary nodes
ko['dataFor'] = node => {
// We can only do something meaningful for elements and comment nodes (in particular, not text nodes, as IE can't store domdata for them)
var context = node && [1,8].includes(node.nodeType) && ko.storedBindingContextForNode(node);
return context ? context['$data'] : undefined;
};
ko.exportSymbol('bindingHandlers', ko.bindingHandlers);
ko.exportSymbol('applyBindings', ko.applyBindings);