snappymail/vendors/knockout/src/templating/templating.js
2022-09-12 22:07:51 +02:00

295 lines
16 KiB
JavaScript

(() => {
var renderTemplateSource = templateSource => {
var templateNodes = templateSource.nodes ? templateSource.nodes() : null;
return templateNodes
? [...templateNodes.cloneNode(true).childNodes]
: null;
},
makeTemplateSource = (template, templateDocument) => {
// Named template
if (typeof template == "string") {
templateDocument = templateDocument || document;
var elem = templateDocument.getElementById(template);
if (!elem)
throw new Error("Cannot find template with ID " + template);
return new ko.templateSources.domElement(elem);
}
if ([1,8].includes(template.nodeType)) {
// Anonymous template
return new ko.templateSources.anonymousTemplate(template);
}
throw new Error("Unknown template type: " + template);
},
invokeForEachNodeInContinuousRange = (firstNode, lastNode, action) => {
var node, nextInQueue = firstNode, firstOutOfRangeNode = ko.virtualElements.nextSibling(lastNode);
while (nextInQueue && ((node = nextInQueue) !== firstOutOfRangeNode)) {
nextInQueue = ko.virtualElements.nextSibling(node);
action(node, nextInQueue);
}
},
activateBindingsOnContinuousNodeArray = (continuousNodeArray, bindingContext) => {
// To be used on any nodes that have been rendered by a template and have been inserted into some parent element
// Walks through continuousNodeArray (which *must* be continuous, i.e., an uninterrupted sequence of sibling nodes, because
// the algorithm for walking them relies on this), and for each top-level item in the virtual-element sense,
// (1) Does a regular "applyBindings" to associate bindingContext with this node and to activate any non-memoized bindings
// (2) Unmemoizes any memos in the DOM subtree (e.g., to activate bindings that had been memoized during template rewriting)
if (continuousNodeArray.length) {
var firstNode = continuousNodeArray[0],
lastNode = continuousNodeArray[continuousNodeArray.length - 1],
parentNode = firstNode.parentNode;
// Need to applyBindings *before* unmemoziation, because unmemoization might introduce extra nodes (that we don't want to re-bind)
// whereas a regular applyBindings won't introduce new memoized nodes
invokeForEachNodeInContinuousRange(firstNode, lastNode, node => {
if (node.nodeType === 1 || node.nodeType === 8)
ko.applyBindings(bindingContext, node);
});
// Make sure any changes done by applyBindings or unmemoize are reflected in the array
ko.utils.fixUpContinuousNodeArray(continuousNodeArray, parentNode);
}
},
getFirstNodeFromPossibleArray = (nodeOrNodeArray) => {
return nodeOrNodeArray.nodeType ? nodeOrNodeArray
: nodeOrNodeArray.length > 0 ? nodeOrNodeArray[0]
: null;
},
executeTemplate = (targetNodeOrNodeArray, renderMode, template, bindingContext) => {
var firstTargetNode = targetNodeOrNodeArray && getFirstNodeFromPossibleArray(targetNodeOrNodeArray);
var templateDocument = (firstTargetNode || template || {}).ownerDocument;
var renderedNodesArray = renderTemplateSource(makeTemplateSource(template, templateDocument));
// Loosely check result is an array of DOM nodes
if ((typeof renderedNodesArray.length != "number") || (renderedNodesArray.length > 0 && typeof renderedNodesArray[0].nodeType != "number"))
throw new Error("Template engine must return an array of DOM nodes");
var haveAddedNodesToParent = false;
switch (renderMode) {
case "replaceChildren":
ko.virtualElements.setDomNodeChildren(targetNodeOrNodeArray, renderedNodesArray);
haveAddedNodesToParent = true;
break;
case "ignoreTargetNode": break;
default:
throw new Error("Unknown renderMode: " + renderMode);
}
if (haveAddedNodesToParent) {
activateBindingsOnContinuousNodeArray(renderedNodesArray, bindingContext);
if (renderMode == "replaceChildren") {
ko.bindingEvent.notify(targetNodeOrNodeArray, ko.bindingEvent.childrenComplete);
}
}
return renderedNodesArray;
},
resolveTemplateName = (template, data, context) => {
// The template can be specified as:
if (ko.isObservable(template)) {
// 1. An observable, with string value
return template();
}
// 2. A function of (data, context) returning a string ELSE 3. A string
return (typeof template === 'function') ? template(data, context) : template;
};
ko.renderTemplate = function (template, dataOrBindingContext, options, targetNodeOrNodeArray, renderMode) {
options = options || {};
renderMode = renderMode || "replaceChildren";
if (targetNodeOrNodeArray) {
var firstTargetNode = getFirstNodeFromPossibleArray(targetNodeOrNodeArray);
var whenToDispose = () => (!firstTargetNode) || !ko.utils.domNodeIsAttachedToDocument(firstTargetNode); // Passive disposal (on next evaluation)
return ko.computed( // So the DOM is automatically updated when any dependency changes
() => {
// Ensure we've got a proper binding context to work with
var bindingContext = (dataOrBindingContext instanceof ko.bindingContext)
? dataOrBindingContext
: new ko.bindingContext(dataOrBindingContext, null, null, null, { "exportDependencies": true });
var templateName = resolveTemplateName(template, bindingContext['$data'], bindingContext);
executeTemplate(targetNodeOrNodeArray, renderMode, templateName, bindingContext, options);
},
{ disposeWhen: whenToDispose, disposeWhenNodeIsRemoved: firstTargetNode }
);
} else {
console.log('no targetNodeOrNodeArray');
}
};
ko.renderTemplateForEach = (template, arrayOrObservableArray, options, targetNode, parentBindingContext) => {
// Since setDomNodeChildrenFromArrayMapping always calls executeTemplateForArrayItem and then
// activateBindingsCallback for added items, we can store the binding context in the former to use in the latter.
var arrayItemContext, asName = options['as'];
// This will be called by setDomNodeChildrenFromArrayMapping to get the nodes to add to targetNode
var executeTemplateForArrayItem = (arrayValue, index) => {
// Support selecting template as a function of the data being rendered
arrayItemContext = parentBindingContext['createChildContext'](arrayValue, {
'as': asName,
'extend': context => {
context['$index'] = index;
if (asName) {
context[asName + "Index"] = index;
}
}
});
var templateName = resolveTemplateName(template, arrayValue, arrayItemContext);
return executeTemplate(targetNode, "ignoreTargetNode", templateName, arrayItemContext, options);
};
// This will be called whenever setDomNodeChildrenFromArrayMapping has added nodes to targetNode
var activateBindingsCallback = (arrayValue, addedNodesArray) => {
activateBindingsOnContinuousNodeArray(addedNodesArray, arrayItemContext);
// release the "cache" variable, so that it can be collected by
// the GC when its value isn't used from within the bindings anymore.
arrayItemContext = null;
};
var setDomNodeChildrenFromArrayMapping = function (newArray, changeList) {
// Call setDomNodeChildrenFromArrayMapping, ignoring any observables unwrapped within (most likely from a callback function).
// If the array items are observables, though, they will be unwrapped in executeTemplateForArrayItem and managed within setDomNodeChildrenFromArrayMapping.
ko.dependencyDetection.ignore(ko.utils.setDomNodeChildrenFromArrayMapping, null, [targetNode, newArray, executeTemplateForArrayItem, options, activateBindingsCallback, changeList]);
ko.bindingEvent.notify(targetNode, ko.bindingEvent.childrenComplete);
};
if (!options['beforeRemove'] && ko.isObservableArray(arrayOrObservableArray)) {
setDomNodeChildrenFromArrayMapping(arrayOrObservableArray.peek());
var subscription = arrayOrObservableArray.subscribe(changeList => {
setDomNodeChildrenFromArrayMapping(arrayOrObservableArray(), changeList);
}, null, "arrayChange");
subscription.disposeWhenNodeIsRemoved(targetNode);
return subscription;
}
return ko.computed(() => {
var unwrappedArray = ko.utils.unwrapObservable(arrayOrObservableArray) || [];
if (typeof unwrappedArray.length == "undefined") // Coerce single value into array
unwrappedArray = [unwrappedArray];
setDomNodeChildrenFromArrayMapping(unwrappedArray);
}, { disposeWhenNodeIsRemoved: targetNode });
};
var templateComputedDomDataKey = ko.utils.domData.nextKey();
function disposeOldComputedAndStoreNewOne(element, newComputed) {
var oldComputed = ko.utils.domData.get(element, templateComputedDomDataKey);
oldComputed?.dispose?.();
ko.utils.domData.set(element, templateComputedDomDataKey, (newComputed && (!newComputed.isActive || newComputed.isActive())) ? newComputed : undefined);
}
var cleanContainerDomDataKey = ko.utils.domData.nextKey();
ko.bindingHandlers['template'] = {
'init': (element, valueAccessor) => {
// Support anonymous templates
var bindingValue = ko.utils.unwrapObservable(valueAccessor());
if (typeof bindingValue == "string" || 'name' in bindingValue) {
// It's a named template - clear the element
ko.virtualElements.emptyNode(element);
} else if ('nodes' in bindingValue) {
// We've been given an array of DOM nodes. Save them as the template source.
// There is no known use case for the node array being an observable array (if the output
// varies, put that behavior *into* your template - that's what templates are for), and
// the implementation would be a mess, so assert that it's not observable.
var nodes = bindingValue['nodes'] || [];
if (ko.isObservable(nodes)) {
throw new Error('The "nodes" option must be a plain, non-observable array.');
}
// If the nodes are already attached to a KO-generated container, we reuse that container without moving the
// elements to a new one (we check only the first node, as the nodes are always moved together)
let container = nodes[0]?.parentNode;
if (!container || !ko.utils.domData.get(container, cleanContainerDomDataKey)) {
container = ko.utils.moveCleanedNodesToContainerElement(nodes);
ko.utils.domData.set(container, cleanContainerDomDataKey, true);
}
new ko.templateSources.anonymousTemplate(element).nodes(container);
} else {
// It's an anonymous template - store the element contents, then clear the element
var templateNodes = ko.virtualElements.childNodes(element);
if (templateNodes.length) {
let container = ko.utils.moveCleanedNodesToContainerElement(templateNodes); // This also removes the nodes from their current parent
new ko.templateSources.anonymousTemplate(element).nodes(container);
} else {
throw new Error("Anonymous template defined, but no template content was provided");
}
}
return { 'controlsDescendantBindings': true };
},
'update': (element, valueAccessor, allBindings, viewModel, bindingContext) => {
var value = valueAccessor(),
options = ko.utils.unwrapObservable(value),
shouldDisplay = true,
templateComputed = null,
template;
if (typeof options == "string") {
template = value;
options = {};
} else {
template = 'name' in options ? options['name'] : element;
// Support "if"/"ifnot" conditions
if ('if' in options)
shouldDisplay = ko.utils.unwrapObservable(options['if']);
if (shouldDisplay && 'ifnot' in options)
shouldDisplay = !ko.utils.unwrapObservable(options['ifnot']);
// Don't show anything if an empty name is given (see #2446)
if (shouldDisplay && !template) {
shouldDisplay = false;
}
}
if ('foreach' in options) {
// Render once for each data point (treating data set as empty if shouldDisplay==false)
var dataArray = (shouldDisplay && options['foreach']) || [];
templateComputed = ko.renderTemplateForEach(template, dataArray, options, element, bindingContext);
} else if (!shouldDisplay) {
ko.virtualElements.emptyNode(element);
} else {
// Render once for this single data point (or use the viewModel if no data was provided)
var innerBindingContext = bindingContext;
if ('data' in options) {
innerBindingContext = bindingContext['createChildContext'](options['data'], {
'as': options['as'],
'exportDependencies': true
});
}
templateComputed = ko.renderTemplate(template, innerBindingContext, options, element);
}
// It only makes sense to have a single template computed per element (otherwise which one should have its output displayed?)
disposeOldComputedAndStoreNewOne(element, templateComputed);
}
};
// Anonymous templates can't be rewritten. Give a nice error message if you try to do it.
ko.expressionRewriting.bindingRewriteValidators['template'] = bindingValue => {
var parsedBindingValue = ko.expressionRewriting.parseObjectLiteral(bindingValue);
if ((parsedBindingValue.length == 1) && parsedBindingValue[0]['unknown'])
return null; // It looks like a string literal, not an object literal, so treat it as a named template (which is allowed for rewriting)
if (ko.expressionRewriting.keyValueArrayContainsKey(parsedBindingValue, "name"))
return null; // Named templates can be rewritten, so return "no error"
return "This template engine does not support anonymous templates nested within its templates";
};
ko.virtualElements.allowedBindings['template'] = true;
})();