I would like to get the name of a property from within its own function. My current approach does not work because the function is nameless. How can I do this?
window.APP = {
models: {
ex_model: kendo.observable({
ex_property: function () {
var property_name = arguments.callee.name.toString();
console.log(property_name);
},
}),
}
}
Thank you.
You can make ex_property have a name. Instead of using function(), you can say function function_name(), and then arguments.callee.name.toString() would return function_name. Like this:
window.APP = {
models: {
ex_model: kendo.observable({
ex_property: function function_name() {
var property_name = arguments.callee.name.toString();
console.log(property_name); // will return function_name
},
}),
}
}
Related
My code doesn't create a new property under the child element of knockout viewmodel that is mapped by knockout.mapping.fromJS.
I have:
//model from Entity Framework
console.log(ko.mapping.toJSON(model));
var viewModel = ko.mapping.fromJS(model, mappingOption);
ko.applyBindings(viewModel);
console.log(ko.mapping.toJSON(viewModel));
The first console.log outputs:
{
"Id": 0,
"CurrentUser": {
"BoardIds": [
{
"Id": 0
}
],
"Id": 1,
"UserName": "foo",
"IsOnline": true
},
"Boards": []
}
And then the mappingOption is:
var mappingOption = {
create: function (options) {
var modelBase = ko.mapping.fromJS(options.data);
modelBase.CurrentUser.UserName = ko.observable(model.CurrentUser.UserName).extend({ rateLimit: 1000 });
//some function definitions
return modelBase;
},
'CurrentUser': {
create: function (options) {
options.data.MessageToPost = ko.observable("test");
return ko.mapping.fromJS(options.data);
}
}
};
I referred to this post to create the custom mapping, but it seemed not working as the second console.log outputs the same JSON to the first one.
Also, I tried to create nested mapping option based on this thread and another one but it didn't work too.
var mappingOption = {
create: function (options) {
//modelBase, modifing UserName and add the functions
var mappingOption2 = {
'CurrentUser': {
create: function (options) {
return (new(function () {
this.MessageToPost = ko.observable("test");
ko.mapping.fromJS(options.data, mappingOption2, this);
})());
}
}
}
return ko.mapping.fromJS(modelBase, mappingOption2);
}
};
How can I correctly add a new property to the original viewmodel?
From the mapping documentation for ko.toJS (toJS and toJSON work the same way as stated in the document)
Unmapping
If you want to convert your mapped object back to a regular JS object, use:
var unmapped = ko.mapping.toJS(viewModel);
This will create an unmapped object containing only the properties of the mapped object that were part of your original JS object
If you want the json to include properties you've added manually either use ko.toJSON instead of ko.mapping.toJSON to include everything, or use the include option when first creating your object to specify which properties to add.
var mapping = {
'include': ["propertyToInclude", "alsoIncludeThis"]
}
var viewModel = ko.mapping.fromJS(data, mapping);
EDIT: In your specific case your mapping options are conflicting with each other. You've set special instructions for the CurrentUser field but then overridden them in the create function. Here's what I think your mapping options should look like:
var mappingOption = {
'CurrentUser': {
create: function (options) {
var currentUser = ko.mapping.fromJS(options.data, {
'UserName': {
create: function(options){
return ko.observable(options.data);
}
},
'include': ["MessageToPost"]
});
currentUser.MessageToPost = ko.observable("test");
return ko.observable(currentUser).extend({ rateLimit: 1000 });
}
}
};
and here's a fiddle for a working example
I want to share or reuse some logic between differents objects, that they will be pretty similar, just changing the "scope".
var Mixin = {
show: function () {
this.container.show();
},
hide: function () {
this.container.hide();
},
play: function (data) {
data.map().append();
}
};
var ObjectA = {
container: $('#container_a');
foo: function () {
this.play(otherData); // Mixin common method?
}
};
var ObjectB = {
container: $('#container_b'),
foo: function () {
this.play(data); // Mixin common method?
}
};
ObjectA.show() // show $('#container_a');
ObjectB.show() // show $('#container_b');
I was trying using underscore
_.extend(ObjectA, Mixin);
but it seems like I have issues with the reference of the Mixin (this reference to the last extended object), like if i need to clone the object and extend it?
Is there any approach to do something similar?
Thanks!!
EDIT: I having issue with the scope of 'this', that is referencing to window, when a pass as a callback a function inherits from the mixin, like this.
PersonMixin = {
mixinFoo: function () {
this.handleResponse();
}
};
Person = {
personMethod: function () {
OtherLibrary.libMehtod(this.mixinFoo);
}
};
Object.assign(Person, PersonMixin);
and then, something like this will fail, this an example stack trace
Person.personMethod();
OtherLibrary.libMethod(callbackMixin);
Ajax.post(callbackMixin);
callbackMixin(response); // this.handleResponse() is not defined, because this reference to window object.
EDIT 2: I can solve this issue using bind()
You can do this in a number of ways, my preference is adjusting the objects __proto__ property on creation which will cause it to inherit your mixin via its prototype chain. This does not require the use of underscore.
I adjusted your example for ES6 and made it a bit simpler but should get the point across.
const PlayerType = (
{ show() {
console.info(`show ${this.name}`)
}
, hide() {
console.info(`hide ${this.name}`)
}
, play: function (data) {
data.map().append();
}
}
)
const objA = { __proto__: PlayerType
, name: 'objA'
, foo(...args) {
this.play(...args)
}
}
const objB = { __proto__: PlayerType
, name: 'objB'
, foo(...args) {
this.play(...args)
}
}
objA.show()
objB.show()
Simpler and no ES6:
var Mixin = (
{ show() {
console.info('show ' + this.name)
}
, hide() {
console.info('hide ' + this.name)
}
}
)
var a = { __proto__: Mixin, name: 'a' }
var b = { __proto__: Mixin, name: 'b' }
a.show()
b.show()
Alternate - Does the same thing with Object.create().
var Mixin = (
{ show() {
console.info('show ' + this.name)
}
, hide() {
console.info('hide ' + this.name)
}
}
)
var a = Object.create(Mixin, { name: { value: 'a', enumerable: true } })
var b = Object.create(Mixin, { name: { value: 'b', enumerable: true } })
a.show()
b.show()
It works, just check your syntax also.
var Mixin = {
show: function() {
console.log(this.tmp);
}
}
var oA = {
tmp: 'tmpA'
}
var oB = {
tmp: 'tmpB'
}
var mA = Object.assign(oA, Mixin);
var mB = Object.assign(oB, Mixin)
mA.show();
mB.show()
I have the following:
$scope.option = {
generateID:function(){
return Math.random().toString(36).replace(/[^a-z]+/g, '').substr(0, 5);
},
values : [
{id:this.generateId()},
{id:this.generateId()},
{id:this.generateId()},
{id:this.generateId()}
],
markCorrect : function(option){
},
remove:function(option)
{
this.values = this.values.filter(function(value){return value.id!=option.id})
}
}
I always get a this.generateId is not a function error. I am pretty sure that i am missing something fundamental here!
It may be better to store the id generator function in a separate function so it is easier to reference:
function generateId = function() {
return Math.random().toString(36).replace(/[^a-z]+/g, '').substr(0, 5);
}
$scope.option = {
generateID: generateId,
values : [
{id: generateId()},
{id: generateId()},
{id: generateId()},
{id: generateId()}
],
markCorrect : function(option){
},
remove:function(option)
{
this.values = this.values.filter(function(value){return value.id!=option.id})
}
}
The primary issue is that you're trying to access properties of $scope.option in the middle of declaring it. Try doing something like this instead:
$scope.option = (function () {
function generateId () {
/* logic */
}
return {
values: [
{id: generateId()}
// ...
],
markCorrect: function () {},
remove: function () {}
};
}) ();
This is the 'revealing module pattern', i.e. a function that returns an object forming a closure on some other data or functionality.
There is a typo; rename generateID to generateId.
I'm trying to get the member ID for a Trello account and then use that member ID in a constructor function to generate boards. My problem is that I can't access the member ID that I return outside of the object I created. How do I access the memberID outside of the TrellloConnect object?
Here is the code:
var TrelloConnect = {
init: function(config) {
this.config = config;
this.doAuthorize();
this.updateLogStatus();
this.bindLogIn();
this.bindLogOut();
this.whenAuthorized();
this.getMemberID();
},
bindLogIn: function() {
this.config.connectButton.click(function() {
Trello.authorize({
type: "redirect",
success: this.doAuthorize,
name: "WonderBoard",
expiration: "never"
});
});
},
bindLogOut: function() {
this.config.disconnectButton.click(function() {
var self = TrelloConnect;
Trello.deauthorize();
self.updateLogStatus();
});
},
doAuthorize: function() {
var self = TrelloConnect;
self.updateLogStatus();
},
updateLogStatus: function() {
var isLoggedIn = Trello.authorized();
this.config.loggedOutContainer.toggle(!isLoggedIn);
this.config.loggedInContainer.toggle(isLoggedIn);
},
whenAuthorized: function() {
Trello.authorize({
interactive: false,
success: TrelloConnect.doAuthorize
});
},
getMemberID: function() {
Trello.members.get("me", function(member) {
console.log(member.id);
return member.id;
});
}
};
TrelloConnect.init({
connectButton: $('#connectLink'),
disconnectButton: $('#disconnect'),
loggedInContainer: $('#loggedin'),
loggedOutContainer: $('#loggedout')
});
function Board(memberID) {
console.log(memberID);
}
var board = new Board(TrelloConnect.getMemberID());
Trello.members.get is an asynchronous function (i.e. it takes a callback instead of returning a value); you'll need to use a callback if you want to do something with the data that it fetches.
If you change getMemberID to take a callback
...
getMemberID: function(callback) {
Trello.members.get("me", function(member){
callback(member.id);
});
}
...
... then you could do something like this:
TrelloConnect.getMemberId(function(id){
new Board(id);
});
Here is a very basic attempt to create a "hello world"-like JS app using the module and MVC patterns.
var appModules = {};
appModules.exampleModul = (function () {
var _data = ['foo', 'bar']; // private variable
return {
view: {
display: function() {
$('body').append(appModules.exampleModul.model.getAsString());
},
},
model: {
getAsString: function() {
return _data.join(', ');
},
}
};
})();
appModules.exampleModul.view.display();
This works fine, but I'm not happy how I have to reference the model function from the view, using the full object path: appModules.exampleModul.model.getAsString(). How can I expose the public model methods to the view, so I could simply use something like model.getAsString()? Or do I need to organize the code differently?
One option is you can convert those objects into private implementations.
appModules.exampleModul = (function() {
var _data = ['foo', 'bar'];
// private variable
var _view = {
display : function() {
$('body').append(_model.getAsString());
},
};
var _model = {
getAsString : function() {
return _data.join(', ');
},
};
return {
view : _view,
model : _model
};
})();
You could do something like this:
var appModules = {};
appModules.exampleModul = (function () {
var _data = ['foo', 'bar']; // private variable
return {
view: {
display: function() {
$('body').append(this.model.getAsString());
},
},
model: {
getAsString: function() {
return _data.join(', ');
},
}
};
})();
var display = appModules.exampleModul.view.display.bind(appModules.exampleModul);
display();
Which isn't really the prettiest of solutions, but does offer a more generic solution inside the display function!