Files
NativeScript/ui/core/bindable.ts
2015-07-01 10:24:02 +03:00

489 lines
18 KiB
TypeScript

import observable = require("data/observable");
import definition = require("ui/core/bindable");
import dependencyObservable = require("ui/core/dependency-observable");
import weakEvents = require("ui/core/weak-event-listener");
import appModule = require("application");
import types = require("utils/types");
import trace = require("trace");
import polymerExpressions = require("js-libs/polymer-expressions");
import bindingBuilder = require("../builder/binding-builder");
import viewModule = require("ui/core/view");
var bindingContextProperty = new dependencyObservable.Property(
"bindingContext",
"Bindable",
new dependencyObservable.PropertyMetadata(undefined, dependencyObservable.PropertyMetadataSettings.Inheritable, onBindingContextChanged)
);
function onBindingContextChanged(data: dependencyObservable.PropertyChangeData) {
var bindable = <Bindable>data.object;
bindable._onBindingContextChanged(data.oldValue, data.newValue);
}
var contextKey = "context";
// this regex is used to get parameters inside [] for example:
// from $parents['ListView'] will return 'ListView'
// from $parents[1] will return 1
var paramsRegex = /\[\s*(['"])*(\w*)\1\s*\]/;
// this regex is used to search for all instaces of '$parents[]' within an expression
var parentsRegex = /\$parents\s*\[\s*(['"]*)\w*\1\s*\]/g;
var bc = bindingBuilder.bindingConstants;
export class Bindable extends dependencyObservable.DependencyObservable implements definition.Bindable {
public static bindingContextProperty = bindingContextProperty;
// TODO: Implement with WeakRef to prevent memory leaks.
private _bindings = {};
get bindingContext(): Object {
return this._getValue(Bindable.bindingContextProperty);
}
set bindingContext(value: Object) {
this._setValue(Bindable.bindingContextProperty, value);
}
public bind(options: definition.BindingOptions, source?: Object) {
var binding: Binding = this._bindings[options.targetProperty];
if (binding) {
binding.unbind();
}
binding = new Binding(this, options);
this._bindings[options.targetProperty] = binding;
var bindingSource = source;
if (!bindingSource) {
bindingSource = this.bindingContext;
binding.sourceIsBindingContext = true;
}
if (!types.isNullOrUndefined(bindingSource)) {
binding.bind(bindingSource);
}
}
public unbind(property: string) {
var binding: Binding = this._bindings[property];
if (binding) {
binding.unbind();
delete this._bindings[property];
}
}
public _updateTwoWayBinding(propertyName: string, value: any) {
var binding: Binding = this._bindings[propertyName];
if (binding) {
binding.updateTwoWay(value);
}
}
public _setCore(data: observable.PropertyChangeData) {
super._setCore(data);
this._updateTwoWayBinding(data.propertyName, data.value);
}
public _onPropertyChanged(property: dependencyObservable.Property, oldValue: any, newValue: any) {
trace.write("Bindable._onPropertyChanged(" + this + ") " + property.name, trace.categories.Binding);
super._onPropertyChanged(property, oldValue, newValue);
if (this instanceof viewModule.View) {
if (property.metadata.inheritable && (<viewModule.View>(<any>this))._isInheritedChange() === true) {
return;
}
}
var binding = this._bindings[property.name];
if (binding && !binding.updating) {
if (binding.options.twoWay) {
trace.write("_updateTwoWayBinding(" + this + "): " + property.name, trace.categories.Binding);
this._updateTwoWayBinding(property.name, newValue);
}
else {
trace.write("_onPropertyChanged(" + this + ") removing binding for property: " + property.name, trace.categories.Binding);
this.unbind(property.name);
}
}
}
public _onBindingContextChanged(oldValue: any, newValue: any) {
var binding: Binding;
for (var p in this._bindings) {
binding = this._bindings[p];
if (binding.updating || !binding.sourceIsBindingContext) {
continue;
}
trace.write(
"Binding target: " + binding.target.get() +
" targetProperty: " + binding.options.targetProperty +
" to the changed context: " + newValue, trace.categories.Binding);
binding.unbind();
if (!types.isNullOrUndefined(newValue)) {
binding.bind(newValue);
}
}
}
}
export class Binding {
options: definition.BindingOptions;
updating = false;
sourceIsBindingContext: boolean;
source: WeakRef<Object>;
target: WeakRef<Bindable>;
private sourceOptions: { instance: WeakRef<any>; property: any };
private targetOptions: { instance: WeakRef<any>; property: any };
constructor(target: Bindable, options: definition.BindingOptions) {
this.target = new WeakRef(target);
this.options = options;
}
public bind(obj: Object) {
if (types.isNullOrUndefined(obj)) {
throw new Error("Expected valid object reference as a source in the Binding.bind method.");
}
/* tslint:disable */
if (typeof (obj) === "number") {
obj = new Number(obj);
}
if (typeof (obj) === "boolean") {
obj = new Boolean(obj);
}
if (typeof (obj) === "string") {
obj = new String(obj);
}
/* tslint:enable */
this.source = new WeakRef(obj);
this.updateTarget(this.getSourceProperty());
if (!this.sourceOptions) {
this.sourceOptions = this.resolveOptions(this.source, this.options.sourceProperty);
}
if (this.sourceOptions) {
var sourceOptionsInstance = this.sourceOptions.instance.get();
if (sourceOptionsInstance instanceof observable.Observable) {
weakEvents.addWeakEventListener(
sourceOptionsInstance,
observable.Observable.propertyChangeEvent,
this.onSourcePropertyChanged,
this);
}
}
}
public unbind() {
if (!this.source) {
return;
}
if (this.sourceOptions) {
var sourceOptionsInstance = this.sourceOptions.instance.get();
if (sourceOptionsInstance) {
weakEvents.removeWeakEventListener(sourceOptionsInstance,
observable.Observable.propertyChangeEvent,
this.onSourcePropertyChanged,
this);
}
}
if (this.source) {
this.source.clear();
}
if (this.sourceOptions) {
this.sourceOptions.instance.clear();
this.sourceOptions = undefined;
}
if (this.targetOptions) {
this.targetOptions = undefined;
}
}
private prepareExpressionForUpdate(): string {
// this regex is used to create a valid RegExp object from a string that has some special regex symbols like [,(,$ and so on.
// Basically this method replaces all matches of 'source property' in expression with '$newPropertyValue'.
// For example: with an expression similar to:
// text="{{ sourceProperty = $parents['ListView'].test, expression = $parents['ListView'].test + 2}}"
// update expression will be '$newPropertyValue + 2'
// then on expression execution the new value will be taken and target property will be updated with the value of the expression.
var escapeRegex = /[-\/\\^$*+?.()|[\]{}]/g;
var escapedSourceProperty = this.options.sourceProperty.replace(escapeRegex, '\\$&');
var expRegex = new RegExp(escapedSourceProperty, 'g');
var resultExp = this.options.expression.replace(expRegex, bc.newPropertyValueKey);
return resultExp;
}
public updateTwoWay(value: any) {
if (this.updating) {
return;
}
if (this.options.twoWay) {
if (this.options.expression) {
var changedModel = {};
changedModel[bc.bindingValueKey] = value;
changedModel[bc.newPropertyValueKey] = value;
var sourcePropertyName = "";
if (this.sourceOptions) {
sourcePropertyName = this.sourceOptions.property;
}
else if (typeof this.options.sourceProperty === "string" && this.options.sourceProperty.indexOf(".") === -1) {
sourcePropertyName = this.options.sourceProperty;
}
if (sourcePropertyName !== "") {
changedModel[sourcePropertyName] = value;
}
var updateExpression = this.prepareExpressionForUpdate();
this.prepareContextForExpression(changedModel, updateExpression);
var expressionValue = this._getExpressionValue(updateExpression, true, changedModel);
if (expressionValue instanceof Error) {
trace.write((<Error>expressionValue).message, trace.categories.Binding, trace.messageType.error);
}
else {
this.updateSource(expressionValue);
}
}
else {
this.updateSource(value);
}
}
}
private _getExpressionValue(expression: string, isBackConvert: boolean, changedModel: any): any {
try {
var exp = polymerExpressions.PolymerExpressions.getExpression(expression);
if (exp) {
var context = this.source && this.source.get && this.source.get() || global;
var model = {};
for (var prop in appModule.resources) {
if (appModule.resources.hasOwnProperty(prop) && !context.hasOwnProperty(prop)) {
context[prop] = appModule.resources[prop];
}
}
this.prepareContextForExpression(context, expression);
model[contextKey] = context;
return exp.getValue(model, isBackConvert, changedModel);
}
return new Error(expression + " is not a valid expression.");
}
catch (e) {
var errorMessage = "Run-time error occured in file: " + e.sourceURL + " at line: " + e.line + " and column: " + e.column;
return new Error(errorMessage);
}
}
public onSourcePropertyChanged(data: observable.PropertyChangeData) {
if (this.options.expression) {
//this.prepareContextForExpression(this.source.get(), this.options.expression);
var expressionValue = this._getExpressionValue(this.options.expression, false, undefined);
if (expressionValue instanceof Error) {
trace.write((<Error>expressionValue).message, trace.categories.Binding, trace.messageType.error);
}
else {
this.updateTarget(expressionValue);
}
} else if (data.propertyName === this.sourceOptions.property) {
this.updateTarget(data.value);
}
}
private prepareContextForExpression(model, expression) {
var parentViewAndIndex;
var parentView;
if (expression.indexOf(bc.parentValueKey) > -1) {
parentView = this.getParentView(this.target.get(), bc.parentValueKey).view;
if (parentView) {
model[bc.parentValueKey] = parentView.bindingContext;
}
}
var parentsArray = expression.match(parentsRegex);
if (parentsArray) {
var i;
for (i = 0; i < parentsArray.length; i++) {
parentViewAndIndex = this.getParentView(this.target.get(), parentsArray[i]);
if (parentViewAndIndex.view) {
model[bc.parentsValueKey] = model[bc.parentsValueKey] || {};
model[bc.parentsValueKey][parentViewAndIndex.index] = parentViewAndIndex.view.bindingContext;
}
}
}
}
private getSourceProperty() {
if (this.options.expression) {
var changedModel = {};
changedModel[bc.bindingValueKey] = this.source.get();
//this.prepareContextForExpression(this.source.get(), this.options.expression);
var expressionValue = this._getExpressionValue(this.options.expression, false, changedModel);
if (expressionValue instanceof Error) {
trace.write((<Error>expressionValue).message, trace.categories.Binding, trace.messageType.error);
}
else {
return expressionValue;
}
}
if (!this.sourceOptions) {
this.sourceOptions = this.resolveOptions(this.source, this.options.sourceProperty);
}
var value;
if (this.sourceOptions) {
var sourceOptionsInstance = this.sourceOptions.instance.get();
if (this.sourceOptions.property === bc.bindingValueKey) {
value = sourceOptionsInstance;
}
else if (sourceOptionsInstance instanceof observable.Observable) {
value = sourceOptionsInstance.get(this.sourceOptions.property);
}
else if (sourceOptionsInstance && this.sourceOptions.property &&
this.sourceOptions.property in sourceOptionsInstance) {
value = sourceOptionsInstance[this.sourceOptions.property];
}
}
return value;
}
private updateTarget(value: any) {
if (this.updating || (!this.target || !this.target.get())) {
return;
}
if (!this.targetOptions) {
this.targetOptions = this.resolveOptions(this.target, this.options.targetProperty);
}
this.updateOptions(this.targetOptions, value);
}
private updateSource(value: any) {
if (this.updating || (!this.source || !this.source.get())) {
return;
}
if (!this.sourceOptions) {
this.sourceOptions = this.resolveOptions(this.source, this.options.sourceProperty);
}
this.updateOptions(this.sourceOptions, value);
}
private getParentView(target, property) {
if (!target || !(target instanceof viewModule.View)) {
return {view: null, index: null};
}
var result;
if (property === bc.parentValueKey) {
result = target.parent;
}
if (property.indexOf(bc.parentsValueKey) === 0) {
result = target.parent;
var indexParams = paramsRegex.exec(property);
var index;
if (indexParams && indexParams.length > 1) {
index = indexParams[2];
}
if (!isNaN(index)) {
var indexAsInt = parseInt(index);
while (indexAsInt > 0) {
result = result.parent;
indexAsInt--;
}
}
else {
while (result && result.typeName !== index) {
result = result.parent;
}
}
}
return { view: result, index: index };
}
private resolveOptions(obj: WeakRef<any>, property: string): { instance: any; property: any } {
var options;
if (property === bc.bindingValueKey) {
options = {
instance: obj,
property: property
};
return options;
}
if (types.isString(property) && property.indexOf(".") !== -1) {
var properties = property.split(".");
var i: number;
var currentObject = obj.get();
for (i = 0; i < properties.length - 1; i++) {
if (properties[i] === bc.bindingValueKey) {
continue;
}
if (properties[i] === bc.parentValueKey || properties[i].indexOf(bc.parentsValueKey) === 0) {
var parentView = this.getParentView(this.target.get(), properties[i]).view;
if (parentView) {
currentObject = parentView.bindingContext;
}
continue;
}
currentObject = currentObject[properties[i]];
}
if (!types.isNullOrUndefined(currentObject)) {
options = {
instance: new WeakRef(currentObject),
property: properties[properties.length - 1]
}
}
} else {
options = {
instance: obj,
property: property
}
}
return options;
}
private updateOptions(options: { instance: WeakRef<any>; property: any }, value: any) {
var optionsInstance;
if (options && options.instance) {
optionsInstance = options.instance.get();
}
if (!optionsInstance) {
return;
}
this.updating = true;
try {
if (optionsInstance instanceof observable.Observable) {
optionsInstance.set(options.property, value);
} else {
optionsInstance[options.property] = value;
}
}
catch (ex) {
trace.write("Binding error while setting property " + options.property + " of " + optionsInstance + ": " + ex,
trace.categories.Binding,
trace.messageType.error);
}
this.updating = false;
}
}