Related
Why does the following work?
<something>.stop().animate(
{ 'top' : 10 }, 10
);
Whereas this doesn't work:
var thetop = 'top';
<something>.stop().animate(
{ thetop : 10 }, 10
);
To make it even clearer: At the moment I'm not able to pass a CSS property to the animate function as a variable.
{ thetop : 10 } is a valid object literal. The code will create an object with a property named thetop that has a value of 10. Both the following are the same:
obj = { thetop : 10 };
obj = { "thetop" : 10 };
In ES5 and earlier, you cannot use a variable as a property name inside an object literal. Your only option is to do the following:
var thetop = "top";
// create the object literal
var aniArgs = {};
// Assign the variable property name with a value of 10
aniArgs[thetop] = 10;
// Pass the resulting object to the animate method
<something>.stop().animate(
aniArgs, 10
);
ES6 defines ComputedPropertyName as part of the grammar for object literals, which allows you to write the code like this:
var thetop = "top",
obj = { [thetop]: 10 };
console.log(obj.top); // -> 10
You can use this new syntax in the latest versions of each mainstream browser.
With ECMAScript 2015 you are now able to do it directly in object declaration with the brackets notation:
var obj = {
[key]: value
}
Where key can be any sort of expression (e.g. a variable) returning a value.
So here your code would look like:
<something>.stop().animate({
[thetop]: 10
}, 10)
Where thetop will be evaluated before being used as key.
ES5 quote that says it should not work
Note: rules have changed for ES6: https://stackoverflow.com/a/2274327/895245
Spec: http://www.ecma-international.org/ecma-262/5.1/#sec-11.1.5
PropertyName :
IdentifierName
StringLiteral
NumericLiteral
[...]
The production PropertyName : IdentifierName is evaluated as follows:
Return the String value containing the same sequence of characters as the IdentifierName.
The production PropertyName : StringLiteral is evaluated as follows:
Return the SV [String value] of the StringLiteral.
The production PropertyName : NumericLiteral is evaluated as follows:
Let nbr be the result of forming the value of the NumericLiteral.
Return ToString(nbr).
This means that:
{ theTop : 10 } is the exact same as { 'theTop' : 10 }
The PropertyName theTop is an IdentifierName, so it gets converted to the 'theTop' string value, which is the string value of 'theTop'.
It is not possible to write object initializers (literals) with variable keys.
The only three options are IdentifierName (expands to string literal), StringLiteral, and NumericLiteral (also expands to a string).
ES6 / 2020
If you're trying to push data to an object using "key:value" from any other source, you can use something like this:
let obj = {}
let key = "foo"
let value = "bar"
obj[`${key}`] = value
// A `console.log(obj)` would return:
// {foo: "bar}
// A `typeof obj` would return:
// "object"
Hope this helps someone :)
I have used the following to add a property with a "dynamic" name to an object:
var key = 'top';
$('#myElement').animate(
(function(o) { o[key]=10; return o;})({left: 20, width: 100}),
10
);
key is the name of the new property.
The object of properties passed to animate will be {left: 20, width: 100, top: 10}
This is just using the required [] notation as recommended by the other answers, but with fewer lines of code!
Adding square bracket around the variable works good for me. Try this
var thetop = 'top';
<something>.stop().animate(
{ [thetop] : 10 }, 10
);
You can also try like this:
const arr = [{
"description": "THURSDAY",
"count": "1",
"date": "2019-12-05"
},
{
"description": "WEDNESDAY",
"count": "0",
"date": "2019-12-04"
}]
const res = arr.map(value => {
return { [value.description]: { count: value.count, date: value.date } }
})
console.log(res);
I couldn't find a simple example about the differences between ES6 and ES5, so I made one. Both code samples create exactly the same object. But the ES5 example also works in older browsers (like IE11), wheres the ES6 example doesn't.
ES6
var matrix = {};
var a = 'one';
var b = 'two';
var c = 'three';
var d = 'four';
matrix[a] = {[b]: {[c]: d}};
ES5
var matrix = {};
var a = 'one';
var b = 'two';
var c = 'three';
var d = 'four';
function addObj(obj, key, value) {
obj[key] = value;
return obj;
}
matrix[a] = addObj({}, b, addObj({}, c, d));
Update: As a commenter pointed out, any version of JavaScript that supports arrow functions will also support ({[myKey]:myValue}), so this answer has no actual use-case (and, in fact, it might break in some bizarre corner-cases).
Don't use the below-listed method.
I can't believe this hasn't been posted yet: just use arrow functions with anonymous evaluation!
Completely non-invasive, doesn't mess with the namespace, and it takes just one line:
myNewObj = ((k,v)=>{o={};o[k]=v;return o;})(myKey,myValue);
demo:
var myKey="valueof_myKey";
var myValue="valueof_myValue";
var myNewObj = ((k,v)=>{o={};o[k]=v;return o;})(myKey,myValue);
console.log(myNewObj);
useful in environments that don't support the new {[myKey]: myValue} syntax yet, such as—apparently; I just verified it on my Web Developer Console—Firefox 72.0.1, released 2020-01-08. I stand corrected; just wrap the thing in parenthesis and it works.
(I'm sure you could potentially make some more powerful/extensible solutions or whatever involving clever use of reduce, but at that point you'd probably be better served by just breaking out the Object-creation into its own function instead of compulsively jamming it all inline)
not that it matters since OP asked this ten years ago, but for completeness' sake and to demonstrate how it is exactly the answer to the question as stated, I'll show this in the original context:
var thetop = 'top';
<something>.stop().animate(
((k,v)=>{o={};o[k]=v;return o;})(thetop,10), 10
);
Given code:
var thetop = 'top';
<something>.stop().animate(
{ thetop : 10 }, 10
);
Translation:
var thetop = 'top';
var config = { thetop : 10 }; // config.thetop = 10
<something>.stop().animate(config, 10);
As you can see, the { thetop : 10 } declaration doesn't make use of the variable thetop. Instead it creates an object with a key named thetop. If you want the key to be the value of the variable thetop, then you will have to use square brackets around thetop:
var thetop = 'top';
var config = { [thetop] : 10 }; // config.top = 10
<something>.stop().animate(config, 10);
The square bracket syntax has been introduced with ES6. In earlier versions of JavaScript, you would have to do the following:
var thetop = 'top';
var config = (
obj = {},
obj['' + thetop] = 10,
obj
); // config.top = 10
<something>.stop().animate(config, 10);
2020 update/example...
A more complex example, using brackets and literals...something you may have to do for example with vue/axios. Wrap the literal in the brackets, so
[ ` ... ` ]
{
[`filter[${query.key}]`]: query.value, // 'filter[foo]' : 'bar'
}
ES5 implementation to assign keys is below:
var obj = Object.create(null),
objArgs = (
(objArgs = {}),
(objArgs.someKey = {
value: 'someValue'
}), objArgs);
Object.defineProperties(obj, objArgs);
I've attached a snippet I used to convert to bare object.
var obj = {
'key1': 'value1',
'key2': 'value2',
'key3': [
'value3',
'value4',
],
'key4': {
'key5': 'value5'
}
}
var bareObj = function(obj) {
var objArgs,
bareObj = Object.create(null);
Object.entries(obj).forEach(function([key, value]) {
var objArgs = (
(objArgs = {}),
(objArgs[key] = {
value: value
}), objArgs);
Object.defineProperties(bareObj, objArgs);
});
return {
input: obj,
output: bareObj
};
}(obj);
if (!Object.entries) {
Object.entries = function(obj){
var arr = [];
Object.keys(obj).forEach(function(key){
arr.push([key, obj[key]]);
});
return arr;
}
}
console(bareObj);
If you want object key to be same as variable name, there's a short hand in ES 2015.
New notations in ECMAScript 2015
var thetop = 10;
var obj = { thetop };
console.log(obj.thetop); // print 10
You can do it this way:
var thetop = 'top';
<something>.stop().animate(
new function() {this[thetop] = 10;}, 10
);
This way also you can achieve desired output
var jsonobj={};
var count=0;
$(document).on('click','#btnadd', function() {
jsonobj[count]=new Array({ "1" : $("#txtone").val()},{ "2" : $("#txttwo").val()});
count++;
console.clear();
console.log(jsonobj);
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<span>value 1</span><input id="txtone" type="text"/>
<span>value 2</span><input id="txttwo" type="text"/>
<button id="btnadd">Add</button>
You could do the following for ES5:
var theTop = 'top'
<something>.stop().animate(
JSON.parse('{"' + theTop + '":' + JSON.stringify(10) + '}'), 10
)
Or extract to a function:
function newObj (key, value) {
return JSON.parse('{"' + key + '":' + JSON.stringify(value) + '}')
}
var theTop = 'top'
<something>.stop().animate(
newObj(theTop, 10), 10
)
I have the following output:
output "regions_data" {
value = regions({
for region, data in var.regions :
regions => "${region}/${data.postcode}"
})
}
Which contains duplicates like(it is intentional):
regions = {
reg1 = {
postcode = "1"
},
reg1 = {
postcode = "1"
},
reg2 = {
postcode = "2"
}
}
How can I remove the duplicates from the output?
Your code does not comply to the basic rules of maps or objects. Nor there is any regions function you use in the code. The provided code is not a proper Terraform syntax.
I believe however, you might have meant the following example:
variable "regions" {
default = {
reg1 = [
{
postcode = 1
area = "oak-county"
},
{
postcode = 2
area = "birch-county"
}
],
reg2 = [
{
postcode = 1
area = "fir-county"
},
{
postcode = 2
area = "pine-county"
}
],
}
}
In a case, when the two maps have the same keys, you can use flatten to break up everything to pieces, then rejoin everything back together:
locals {
flatten = flatten([
for region_key, region in var.regions : [
for area in region :
{
key = "${region_key}-${area.postcode}"
value = area.area
}
]
])
}
output "flattened_regions" {
value = local.flatten
}
output "remap" {
value = { for key, data in local.flatten :
data.key => data.value
}
}
Even if the code above doesn't exactly fit your case, please experiment in a similar manner - or, provide more complete example of variables you have and the outcome you need.
Source: https://www.terraform.io/language/functions/flatten
Probably what you want
I have no idea what you've meant by regions in value = regions({ but I assume that this code will do what you want:
locals {
regions = {
reg1 = {
postcode = "1"
},
reg1 = {
postcode = "1"
},
reg2 = {
postcode = "2"
}
}
}
output "regions_data" {
value = {
for region, data in local.regions :
region => "${region}/${data.postcode}"
}
}
Keep in mind that I replaced var with local to have one file.
And output of such is:
regions_data = {
"reg1" = "reg1/1"
"reg2" = "reg2/2"
}
Thought be warned that it will use one of keys. It doesn't check for duplicates. It just takes first one.
But why you shouldn't want it
This solution is quite bad for multiple reasons:
You provide variables - why the heck would you put duplicates? :)
As I said this merge will not necessarily provide the output you what
If var is provided by some terraform code (e.g. this regions_data is in module) then logic of merging should be done outside of module and probably terraform's own merge would be the answer.
I have a filter that isn't compatible with WebGL. Is there a way to skip writing a fragmentSource? I tried overriding fabric.Image.filters.BaseFilter applyTo on the filter subclass to only call this.applyTo2d(options); but I'm not getting any image data.
applyTo: function(options) {
if (options.webgl) {
if (options.passes > 1 && this.isNeutralState(options)) {
// avoid doing something that we do not need
return;
}
this._setupFrameBuffer(options);
this.applyToWebGL(options);
this._swapTextures(options);
}
else if (!this.isNeutralState()) {
this.applyTo2d(options);
}
},
I as able to accomplish this in a non-optimized way with minimal code in webgl_backend.class.js.
First, the webgl backend needs a fallback for non-webgl filters:
this.fallback2dBackend = new fabric.Canvas2dFilterBackend();
Then, instead of running all filters: fabric.filterBackend.applyFilters(filters, this._originalElement, sourceWidth, sourceHeight, this._element, this.cacheKey);
Do this:
var newSource = fabric.util.createCanvasElement();
newSource.width = sourceWidth;
newSource.height = sourceHeight;
var newSourceCtx = newSource.getContext('2d');
newSourceCtx.drawImage(this._originalElement, 0, 0, sourceWidth, sourceHeight);
filters.forEach(function(filter) {
if (!filter) {
return;
}
var backend = fabric.filterBackend;
if (filter.fragmentSource === null) {
backend = backend.fallback2dBackend;
}
backend.applyFilters(
[filter], newSource, sourceWidth, sourceHeight, this._element);
newSourceCtx.clearRect(0, 0, sourceWidth, sourceHeight);
newSourceCtx.drawImage(this._element, 0, 0, sourceWidth, sourceHeight);
}, this);
I've published a fork in case someone wants to refactor this into a PR.
Why does the following work?
<something>.stop().animate(
{ 'top' : 10 }, 10
);
Whereas this doesn't work:
var thetop = 'top';
<something>.stop().animate(
{ thetop : 10 }, 10
);
To make it even clearer: At the moment I'm not able to pass a CSS property to the animate function as a variable.
{ thetop : 10 } is a valid object literal. The code will create an object with a property named thetop that has a value of 10. Both the following are the same:
obj = { thetop : 10 };
obj = { "thetop" : 10 };
In ES5 and earlier, you cannot use a variable as a property name inside an object literal. Your only option is to do the following:
var thetop = "top";
// create the object literal
var aniArgs = {};
// Assign the variable property name with a value of 10
aniArgs[thetop] = 10;
// Pass the resulting object to the animate method
<something>.stop().animate(
aniArgs, 10
);
ES6 defines ComputedPropertyName as part of the grammar for object literals, which allows you to write the code like this:
var thetop = "top",
obj = { [thetop]: 10 };
console.log(obj.top); // -> 10
You can use this new syntax in the latest versions of each mainstream browser.
With ECMAScript 2015 you are now able to do it directly in object declaration with the brackets notation:
var obj = {
[key]: value
}
Where key can be any sort of expression (e.g. a variable) returning a value.
So here your code would look like:
<something>.stop().animate({
[thetop]: 10
}, 10)
Where thetop will be evaluated before being used as key.
ES5 quote that says it should not work
Note: rules have changed for ES6: https://stackoverflow.com/a/2274327/895245
Spec: http://www.ecma-international.org/ecma-262/5.1/#sec-11.1.5
PropertyName :
IdentifierName
StringLiteral
NumericLiteral
[...]
The production PropertyName : IdentifierName is evaluated as follows:
Return the String value containing the same sequence of characters as the IdentifierName.
The production PropertyName : StringLiteral is evaluated as follows:
Return the SV [String value] of the StringLiteral.
The production PropertyName : NumericLiteral is evaluated as follows:
Let nbr be the result of forming the value of the NumericLiteral.
Return ToString(nbr).
This means that:
{ theTop : 10 } is the exact same as { 'theTop' : 10 }
The PropertyName theTop is an IdentifierName, so it gets converted to the 'theTop' string value, which is the string value of 'theTop'.
It is not possible to write object initializers (literals) with variable keys.
The only three options are IdentifierName (expands to string literal), StringLiteral, and NumericLiteral (also expands to a string).
ES6 / 2020
If you're trying to push data to an object using "key:value" from any other source, you can use something like this:
let obj = {}
let key = "foo"
let value = "bar"
obj[`${key}`] = value
// A `console.log(obj)` would return:
// {foo: "bar}
// A `typeof obj` would return:
// "object"
Hope this helps someone :)
I have used the following to add a property with a "dynamic" name to an object:
var key = 'top';
$('#myElement').animate(
(function(o) { o[key]=10; return o;})({left: 20, width: 100}),
10
);
key is the name of the new property.
The object of properties passed to animate will be {left: 20, width: 100, top: 10}
This is just using the required [] notation as recommended by the other answers, but with fewer lines of code!
Adding square bracket around the variable works good for me. Try this
var thetop = 'top';
<something>.stop().animate(
{ [thetop] : 10 }, 10
);
You can also try like this:
const arr = [{
"description": "THURSDAY",
"count": "1",
"date": "2019-12-05"
},
{
"description": "WEDNESDAY",
"count": "0",
"date": "2019-12-04"
}]
const res = arr.map(value => {
return { [value.description]: { count: value.count, date: value.date } }
})
console.log(res);
I couldn't find a simple example about the differences between ES6 and ES5, so I made one. Both code samples create exactly the same object. But the ES5 example also works in older browsers (like IE11), wheres the ES6 example doesn't.
ES6
var matrix = {};
var a = 'one';
var b = 'two';
var c = 'three';
var d = 'four';
matrix[a] = {[b]: {[c]: d}};
ES5
var matrix = {};
var a = 'one';
var b = 'two';
var c = 'three';
var d = 'four';
function addObj(obj, key, value) {
obj[key] = value;
return obj;
}
matrix[a] = addObj({}, b, addObj({}, c, d));
Update: As a commenter pointed out, any version of JavaScript that supports arrow functions will also support ({[myKey]:myValue}), so this answer has no actual use-case (and, in fact, it might break in some bizarre corner-cases).
Don't use the below-listed method.
I can't believe this hasn't been posted yet: just use arrow functions with anonymous evaluation!
Completely non-invasive, doesn't mess with the namespace, and it takes just one line:
myNewObj = ((k,v)=>{o={};o[k]=v;return o;})(myKey,myValue);
demo:
var myKey="valueof_myKey";
var myValue="valueof_myValue";
var myNewObj = ((k,v)=>{o={};o[k]=v;return o;})(myKey,myValue);
console.log(myNewObj);
useful in environments that don't support the new {[myKey]: myValue} syntax yet, such as—apparently; I just verified it on my Web Developer Console—Firefox 72.0.1, released 2020-01-08. I stand corrected; just wrap the thing in parenthesis and it works.
(I'm sure you could potentially make some more powerful/extensible solutions or whatever involving clever use of reduce, but at that point you'd probably be better served by just breaking out the Object-creation into its own function instead of compulsively jamming it all inline)
not that it matters since OP asked this ten years ago, but for completeness' sake and to demonstrate how it is exactly the answer to the question as stated, I'll show this in the original context:
var thetop = 'top';
<something>.stop().animate(
((k,v)=>{o={};o[k]=v;return o;})(thetop,10), 10
);
Given code:
var thetop = 'top';
<something>.stop().animate(
{ thetop : 10 }, 10
);
Translation:
var thetop = 'top';
var config = { thetop : 10 }; // config.thetop = 10
<something>.stop().animate(config, 10);
As you can see, the { thetop : 10 } declaration doesn't make use of the variable thetop. Instead it creates an object with a key named thetop. If you want the key to be the value of the variable thetop, then you will have to use square brackets around thetop:
var thetop = 'top';
var config = { [thetop] : 10 }; // config.top = 10
<something>.stop().animate(config, 10);
The square bracket syntax has been introduced with ES6. In earlier versions of JavaScript, you would have to do the following:
var thetop = 'top';
var config = (
obj = {},
obj['' + thetop] = 10,
obj
); // config.top = 10
<something>.stop().animate(config, 10);
2020 update/example...
A more complex example, using brackets and literals...something you may have to do for example with vue/axios. Wrap the literal in the brackets, so
[ ` ... ` ]
{
[`filter[${query.key}]`]: query.value, // 'filter[foo]' : 'bar'
}
ES5 implementation to assign keys is below:
var obj = Object.create(null),
objArgs = (
(objArgs = {}),
(objArgs.someKey = {
value: 'someValue'
}), objArgs);
Object.defineProperties(obj, objArgs);
I've attached a snippet I used to convert to bare object.
var obj = {
'key1': 'value1',
'key2': 'value2',
'key3': [
'value3',
'value4',
],
'key4': {
'key5': 'value5'
}
}
var bareObj = function(obj) {
var objArgs,
bareObj = Object.create(null);
Object.entries(obj).forEach(function([key, value]) {
var objArgs = (
(objArgs = {}),
(objArgs[key] = {
value: value
}), objArgs);
Object.defineProperties(bareObj, objArgs);
});
return {
input: obj,
output: bareObj
};
}(obj);
if (!Object.entries) {
Object.entries = function(obj){
var arr = [];
Object.keys(obj).forEach(function(key){
arr.push([key, obj[key]]);
});
return arr;
}
}
console(bareObj);
If you want object key to be same as variable name, there's a short hand in ES 2015.
New notations in ECMAScript 2015
var thetop = 10;
var obj = { thetop };
console.log(obj.thetop); // print 10
You can do it this way:
var thetop = 'top';
<something>.stop().animate(
new function() {this[thetop] = 10;}, 10
);
This way also you can achieve desired output
var jsonobj={};
var count=0;
$(document).on('click','#btnadd', function() {
jsonobj[count]=new Array({ "1" : $("#txtone").val()},{ "2" : $("#txttwo").val()});
count++;
console.clear();
console.log(jsonobj);
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<span>value 1</span><input id="txtone" type="text"/>
<span>value 2</span><input id="txttwo" type="text"/>
<button id="btnadd">Add</button>
You could do the following for ES5:
var theTop = 'top'
<something>.stop().animate(
JSON.parse('{"' + theTop + '":' + JSON.stringify(10) + '}'), 10
)
Or extract to a function:
function newObj (key, value) {
return JSON.parse('{"' + key + '":' + JSON.stringify(value) + '}')
}
var theTop = 'top'
<something>.stop().animate(
newObj(theTop, 10), 10
)
If I want a module that is instantiable, let say, a module that handles storing preferences in a subcookies, and i want the main cookie to be configurable, but i don't want it to be a widget... what patterns should i use with YUI?
the end code should be something:
Y.use('my-pref-manager', function(Y){
var A = Y.my-pref-manager.prefStore('A"),
B = Y.my-pref-manager.prefStore('B");
// A and B are now loaded with the contents of cookies A and B, if they exist
A.set('xy', 123 );
});
So far i either found patterns that create widgets within my-module or i have to use methods directly in my-method which will be globals and lack initializers, etc.
There is a bunch of ways of doing this. You could do it using Y.Base.create, like below. The code might not be production ready, or even working properly, but hopefully it answers how you can create a module without it being a Widget.
The code below creates a module that extends Y.Base. This let us use Attributes and other cool things. Check the doc for Y.Base.
YUI.add('my-pref-manager', function (Y) {
var PrefManager = Y.Base.create('myPrefManager', Y.Base, [], {
initializer: function () {
this.after('prefsChange', this.changePref);
},
changePref: function (e) {
Y.Cookie.setSub(this.get('prefStore'), e.subAttrName, this.get(e.subAttrName));
},
setPref: function (name, val) {
this.set('prefs.'+name, val);
},
getPref: function (name) {
return this.get('prefs.'+name);
}
}, {
ATTRS: {
prefStore: {
value: null,
setter: function (val) {
return Y.Cookie.set(val, val);
}
},
prefs: {
value: {}
}
}
});
Y.namespace('My').PrefManager = PrefManager;
}, '0.0.1', {
requires: ['base', 'cookie']
});
YUI().use('my-pref-manager', function (Y) {
var A = new Y.My.PrefManager({prefStore: 'userPrefs'}),
B = new Y.My.PrefManager({prefStore: 'displayPrefs'});
A.setPref('x', 3);
A.setPref('y', 54);
B.setPref('tty', 7);
console.log(A.getPref('x')); // 3
});
Try it out: http://jsfiddle.net/B62nu/