i have problem rendering my view...the view return always the last in the json object: This is the code:
Router.js:
var list = new clientCollection();
var cards = new cardsView({model:list})
list.fetch({success: function (collection, response, options) {
cards.render();
}
});
Cards.js view:
....
tagName: 'section',
className: 'list',
template: Handlebars.compile(cardsTemplate),
render: function () {
var list = this.model.toJSON(),
self = this,
wrapperHtml = $("#board"),
fragment = document.createDocumentFragment();
$(list).each(function (index, item) {
$(self.el).html(self.template({card: item}));
$.each(item.cards, function (i, c) {
var card = new cardView({model : c});
$(self.el).find('.list-cards').append(card.render().el);
});
fragment.appendChild(self.el);
});
wrapperHtml.append(fragment.cloneNode(true));
},
...
This is my json data:
[
{"id":"9","name_client":"XXXXXXX","cards":[]},
{"id":"8","name_client":"XXXXXXX","cards":[{"id":"8","title":"xxxxx.it","description":"some desc","due_date":"2016-01-23","sort":"0"}]}
]
Can u help me to render the view?
It's hard to know for sure without seeing how the view(s) are attached to the DOM, but your problem appears to be this line ...
$(self.el).html(self.template({card: item}));
That is essentially rendering each element in the collection as the full contents of this view, then replacing it on each iteration. Try instead appending the contents of each template to the view's element.
Also, since you tagged this with backbone.js and collections, note that the easier, more Backbone-y way to iterate through a collection would be:
this.model.each(function(item) {
// 'item' is now an instance of the Backbone.Model type
// contained within the collection. Also, note the use
// of 'this' within the iterator function, as well as
// this.$el within a View is automatically the same as
// $(self.el)
this.$el.append(this.template({ card: item });
// ... and so on ...
// By providing 'this' as the second argument to 'each(...)',
// the context of the iterator function is set for you.
}, this);
There's a lot packed in there, so ...
Backbone.Collection Underscore Methods
Backbone.View this.$el
Related
I am storing some settings in the database with keys and JSON data but when I get these settings from a Laravel API, it returns an array which becomes a hectic work in reassigning data to the input fields. I want to know if there is an easier way of doing it.
So far I have tried iterating and using the switch statement to identify keys and reassign them. But the problem is I can't access the VueJS data variable in the loop.
Here is a look at the database table:
Database Table
Here are the objects I am using in Vue:
helpful_notification: {
email: false,
sms: false,
push: false,
},
updates_newsletter: {
email: false,
sms: false,
push: false,
},
Here is my Code to Iterate over results:
axios.get('/api/notificationsettings')
.then(response => {
var data = response.data;
let list = [];
console.log(data)
$.each(data, function(i, j){
switch(j.key){
case 'transactional':
var settings = JSON.parse(j.settings)
var x = {
transactional : settings
}
list.push(x)
break;
case 'task_reminder':
var settings = JSON.parse(j.settings)
x = {
task_reminder : settings
}
list.push(x)
break;
}
});
this.transactional = list;
// this.task_reminder= list.task_reminder;
console.log(list);
})
.catch(error => {
});
In JavaScript, functions have their own scope, save for a few exceptions. Which means that, inside your anonymous function (i.e:
$.each(data, function(i, j){
// this here is the function scope, not the outside scope
})
...), this is not the outside scope, it's the function's scope
There are two ways to make the outside scope available inside your function:
a) place it inside a variable
const _this = this;
$.each(data, function(i, j){
// this is function scope,
// _this is outside scope (i.e: _this.list.task_reminder)
})
b) use an arrow function
$.each(data, (i, j) => {
// this is the outside scope
// the arrow function doesn't have a scope.
})
The above is a simplification aimed at helping you access the outside scope inside your function. But this can differ based on the context it is used in. You can read more about this here.
I've read in several places that the key difference is that this is lexically bound in arrow functions. That's all well and good, but I don't actually know what that means.
I know it means it's unique within the confines of the braces defining the function's body, but I couldn't actually tell you the output of the following code, because I have no idea what this is referring to, unless it's referring to the fat arrow function itself....which doesn't seem useful.
var testFunction = () => {
console.log(this)
};
testFunction();
Arrow functions capture the this value of the enclosing context
function Person(){
this.age = 0;
setInterval(() => {
this.age++; // |this| properly refers to the person object
}, 1000);
}
var p = new Person();
So, to directly answer your question, this inside your arrow function would have the same value as it did right before the arrow function was assigned.
In order to provide the big picture I'm going to explain both, dynamic and lexical binding.
Dynamic Name Binding
this refers to the object the method is called on. This is a regularly to be read sentence on SO. But it is still only a phrase, pretty abstract. Is there a corresponding code pattern to this sentence?
Yes there is:
const o = {
m() { console.log(this) }
}
// the important patterns: applying methods
o.m(); // logs o
o["m"](); // logs o
m is a method because it relies on this. o.m() or o["m"]() means m is applied to o. These patterns are the Javascript translation to our famous phrase.
There is another important code pattern that you should pay attention to:
"use strict";
const o = {
m() { console.log(this) }
}
// m is passed to f as a callback
function f(m) { m() }
// another important pattern: passing methods
f(o.m); // logs undefined
f(o["m"]); // logs undefined
It is very similar to the previous pattern, only the parenthesis are missing. But the consequences are considerable: When you pass m to the function f, you pull outm of its object/context o. It is uprooted now and this refers to nothing (strict mode assumed).
Lexical (or Static) Name Binding
Arrow functions don't have their own this/super/arguments binding. They inherit them from their parent lexical scope:
const toString = Object.prototype.toString;
const o = {
foo: () => console.log("window", toString.call(this)),
bar() {
const baz = () => console.log("o", toString.call(this));
baz();
}
}
o.foo() // logs window [object Window]
o.bar() // logs o [object Object]
Apart from the global scope (Window in browsers) only functions are able to form a scope in Javascript (and {} blocks in ES2015). When the o.foo arrow function is called there is no surrounding function from which baz could inherit its this. Consequently it captures the this binding of the global scope which is bound to the Window object.
When baz is invoked by o.bar, the arrow function is surrounded by o.bar (o.bar forms its parent lexical scope) and can inherit o.bar's this binding. o.bar was called on o and thus its this is bound to o.
Hope this code show could give you clearer idea. Basically, 'this' in arrow function is the current context version of 'this'. See the code:
// 'this' in normal function & arrow function
var this1 = {
number: 123,
logFunction: function () { console.log(this); },
logArrow: () => console.log(this)
};
this1.logFunction(); // Object { number: 123}
this1.logArrow(); // Window
Arrow function this is pointing to the surrounding parent in Es6, means it doesn't scope like anonymous functions in ES5...
It's very useful way to avoid assigning var self to this which is widely used in ES5...
Look at the example below, assigning a function inside an object:
var checkThis = {
normalFunction: function () { console.log(this); },
arrowFunction: () => console.log(this)
};
checkThis.normalFunction(); //Object {}
checkThis.arrowFunction(); //Window {external: Object, chrome: Object, document: document, tmpDebug: "", j: 0…}
You can try to understand it by following the way below
// whatever here it is, function or fat arrow or literally object declare
// in short, a pair of curly braces should be appeared here, eg:
function f() {
// the 'this' here is the 'this' in fat arrow function below, they are
// bind together right here
// if 'this' is meaningful here, eg. this === awesomeObject is true
console.log(this) // [object awesomeObject]
let a = (...param) => {
// 'this is meaningful here too.
console.log(this) // [object awesomeObject]
}
so 'this' in fat arrow function is not bound, means you can not make anything bind to 'this' here, .apply won't, .call won't, .bind won't. 'this' in fat arrow function is bound when you write down the code text in your text editor. 'this' in fat arrow function is literally meaningful here. What your code write here in text editor is what your app run there in repl. What 'this' bound in fat arror will never change unless you change it in text editor.
Sorry for my pool English...
Arrow function never binds with this keyword
var env = "globalOutside";
var checkThis = {env: "insideNewObject", arrowFunc: () => {
console.log("environment: ", this.env);
} }
checkThis.arrowFunc() // expected answer is environment: globalOutside
// Now General function
var env = "globalOutside";
var checkThis = {env: "insideNewObject", generalFunc: function() {
console.log("environment: ", this.env);
} }
checkThis.generalFunc() // expected answer is enviroment: insideNewObject
// Hence proving that arrow function never binds with 'this'
this will always refer to the global object when used inside an arrow function. Use the regular function declaration to refer to the local object. Also, you can use the object name as the context (object.method, not this.method) for it to refer to the local object instead of the global(window).
In another example, if you click the age button below
<script>
var person = {
firstName: 'John',
surname: 'Jones',
dob: new Date('1990-01-01'),
isMarried: false,
age: function() {
return new Date().getFullYear() - this.dob.getFullYear();
}
};
var person2 = {
firstName: 'John',
surname: 'Jones',
dob: new Date('1990-01-01'),
isMarried: false,
age: () => {
return new Date().getFullYear() - this.dob.getFullYear();
}
};
</script>
<input type=button onClick="alert(person2.age());" value="Age">
it will throw an exception like this
×JavaScript error: Uncaught TypeError: Cannot read property
'getFullYear' of undefined on line 18
But if you change person2's this line
return new Date().getFullYear() - this.dob.getFullYear();
to
return new Date().getFullYear() - person2.dob.getFullYear();
it will work because this scope has changed in person2
Differences between arrow functions to regular functions: (taken from w3schools)
With arrow functions there are no binding of this.
In regular functions the this keyword represented the object that called the function, which could be the window, the document, a button or whatever.
With arrow functions the this keyword always represents the object that defined the arrow function.
// Regular Function:
hello = function() {
document.getElementById("demo").innerHTML += this;
}
// The window object calls the function:
window.addEventListener("load", hello);
// A button object calls the function:
document.getElementById("btn").addEventListener("click", hello);
// -------------------------------------------
// Arrow function
hello2 = () => {
document.getElementById("demo2").innerHTML += this;
}
// The window object calls the function:
window.addEventListener("load", hello2);
// A button object calls the function:
document.getElementById("btn2").addEventListener("click", hello2);
<p><i>With a regular function this represents the <b>object that calls the function</b>:</i></p>
<button id='btn'>click me regular function</button>
<p id="demo">Regular function: </p>
<hr>
<p><i>With arrow function this represents the <b>owner of the function(=the window object)</b>:</i></p>
<button id='btn2'>click me arrow function</button>
<p id="demo2">Arrow function: </p>
A related issue:
Came from - Why can't I access `this` within an arrow function?
We know below from here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions
Does not have its own bindings to this or super, and should not be used as methods.
Arrow functions establish "this" based on the scope the Arrow function is defined within.
Had a issue with this using arrow functions, so created a class (can be function), and class variable is accessed in arrow function, thereby achieved smaller functions using arrow functions without function keyword:
class MyClassOrFunction {
values = [];
size = () => this.values.length;
isEmpty = () => this.size() === 0;
}
let obj = new MyClassOrFunction();
obj.size(); // function call here
You can also have a getter like this, that does not have function keyword, but a bit longer due to return statement, also can access other member functions:
class MyClassOrFunction {
values = [];
size = () => this.values.length;
get length() { return this.size(); }
}
let obj = new MyClassOrFunction();
obj.length; // NOTE: no function call here
Following the advice given on one of my other questions (Get a list of all objects from loaded model), I added this code on my application to retrieve all properties from all objects:
function onGeometryLoadedEvent(viewer) {
var dbIds = Object.keys(
viewer.model.getData().instanceTree.nodeAccess.dbIdToIndex
);
this.viewer.model.getBulkProperties(
dbIds,
{
propFilter: false,
ignoreHidden: true
},
(objects) => console.log(objects),
() => console.log('error')
)
}
It correctly shows all the objects. The problem is it takes A LOT of time to complete (+1 minute), even for a model with just 10,000 objects.
Is this normal?
I really need the list of objects with their categories, I have to sort them after getting them to present a list of all the available categories and properties to the user.
I know I can use the Model Derivatives API, but I'd like to avoid it if possible.
Note that when you list all elements on the model it will include those that are not visible, like categories. If you need only elements on the model, then you need the leaf of the model. This article described it and the source code is below:
function getAllLeafComponents(viewer, callback) {
var cbCount = 0; // count pending callbacks
var components = []; // store the results
var tree; // the instance tree
function getLeafComponentsRec(parent) {
cbCount++;
if (tree.getChildCount(parent) != 0) {
tree.enumNodeChildren(parent, function (children) {
getLeafComponentsRec(children);
}, false);
} else {
components.push(parent);
}
if (--cbCount == 0) callback(components);
}
viewer.getObjectTree(function (objectTree) {
tree = objectTree;
var allLeafComponents = getLeafComponentsRec(tree.getRootId());
});
}
Now with the .getBulkProperties you can specify which property you want, so something like Category, right? So specify that, as shown at this article and used with the above .getAllLeafComponent function:
getAllLeafComponents(viewer, function (dbIds) {
viewer.model.getBulkProperties(dbIds, ['Category'],
function(elements){
// ToDo here
// this will only include leaf with Category property
})
})
And I would expect this to be faster than your original code, as I'm filtering elements and properties.
I have 5 tabs with the same user's data. Each tab has an input to search by term. How can reuse code for fetching users and searching them in opened tab. Code is in this JSFiddle:
var listing = Vue.extend({
data: function () {
return {
query: '',
list: [],
user: '',
}
},
computed: {
computedList: function () {
var vm = this;
return this.list.filter(function (item) {
return item.toLowerCase().indexOf(vm.query.toLowerCase()) !== -1
})
}
},
created: function () {
this.loadItems();
},
methods: {
loadItems: function () {
this.list = ['mike','bill','tony'],
},
}
});
var list1 = new listing({
template: '#users-template'
});
var list2 = new listing({
template: '#users-template2'
});
Vue.component('list1', list1);
Vue.component('list2', list2)
var app = new Vue({
el: ".lists-wrappers",
});
query - string of term to search
ComputedList - array of filtered data by search term.
But getting error for "query" and "ComputedList".
[Vue warn]: Property or method "query" is not defined on the instance but referenced during render. Make sure to declare reactive data properties in the data option. (found in root instance).
You were really close with what you had. The reason for the query error is you were using query in what looked like, to Vue, the root instances scope. You shouldn't put templates inside of other templates. Always have them outside of it (preferably as a string in your component definition).
You can read about that a bit here: https://vuejs.org/guide/components.html#DOM-Template-Parsing-Caveats
Here's how I'd approach your situation: https://jsfiddle.net/crswll/apokjqxx/6/
how do i use a for each loop to create accordian containers for each data returned from json file using ajax ?
i have tried this ! is it the way to it ?
dojo.xhrGet({
url:"json/"file_Name".json",
handleAs: "json",
timeout: 10000,
load: function(response,details){
container(response)},
error: function(error_msg,details){
container(error_msg, details);
}
});
//how do i use the json file to add data to the array arrFruit and then create dijit accordian container for every data in the array//
container = function(array, domConstruct) {
var arrFruit = ["apples", "kiwis", "pineapples"];
array.forEach(arrFruit, function(item, i){
domConstruct.create("li", {innerHTML: i+1+". "+item}, "properties");
});
};
//the response data from my json file is:-
[
{
"itemId": 1234,
"Name": "Name",
}]
I would suggest you re-write it into leveraging the ItemFileReadStore. The Store is a data container in which you can pull out items by their id. This means that your json needs to be changed slightly with description of what is identifier and - if any - which is the children attribute keys.
JSON:
{
identifier: 'itemId',
// you dont seem to have child references any but these are defaults
childrenAttrs: ['items', 'children'],
items: [
{
itemId: 1234,
name: 'Name'
}, {
...
}
]
}
then in your code, instead of using .xhr use .fetch in a store like so:
// 1.7+ syntax, pulling in dependencies.
// We want accordion and some other display widget like contentpane.
// Also we await domReady before calling our function
require(["dojo/data/ItemFileReadStore", "dijit/layout/AccordionContainer", "dijit/layout/ContentPane", "dojo/domReady!"], function(itemStore, accordion, contenpane) {
// this section is called when loading of itemstore dependencies are done
// create store
var store = new itemStore({
url:"json/"file_Name".json"
});
// create container
var acc = new accordion({style:"height: 300px"}, 'someDomNodeId');
// call XHR via .fetch and assign onComplete (opposed to 'load') callback
store.fetch({ onComplete: function(items) {
// items is an array of all the objects kept in jsonObject.items array
items.forEach(function(item) {
acc.addChild(new contentpane({
title: "Name for id: " + store.getValue(item, 'itemId'),
content: store.getValue(item, 'name')
}));
});
console.log(acc.getChildren()); // << would print out an array of contentpane widgets
});
});
This is howto :)
At any given time you could use the store and fetch some items, lets say you want to filter out some specific ones, call .query like so: store.fetch({query: { name: '*foo'/*all item.name ending with foo*/ }, onComplete: function(items) { /*cb func*/});
See
http://livedocs.dojotoolkit.org/dijit/layout/AccordionContainer#programmatic-example
and
http://livedocs.dojotoolkit.org/dojo/data/ItemFileReadStore