AngularJs why is object undefined on ng-disabled function? - javascript

VIEW:
I have a rows repeating , with a save button on each row to save each object individually. I want this button to be disabled if no changes have been made.
<tr ng-repeat="option in options | filter:search">
<a ng-click="save(option)" ng-disabled="isUnchanged(option)">Save</a>
</tr>
CONTOLLER:
So I pass the option object to the function, I get its index position in the array. Then compare this 'option' object to its original self in apiKeyOptions[index] which is injected as a service.
angular.module('PartOfApp')
.controller('PartOfAppCtrl', function( $scope, ... apiKeyOptions) {
$scope.options = apiKeyOptions;
$scope.isUnchanged = function(option) {
var index = $scope.options.indexOf(option);
//compare object to the original
if(option.value == apiKeyOptions[index].value && apiKeyOptions[index].setting == option.setting){
//then no changes have been made to this
return true;
}else{
return false;
}
For some reason I get a console of 100's of errors when any data is changed, saying that the apiKeyOptions[index].value and apiKeyOptions[index].setting are undefind.
The app works perfectly as it should returning true if they are the same but still throws a
TypeError: Cannot read property 'value' of undefined
on apiKeyOptions[index]
if I console.log(apiKeyOptions[index].value) I get no undefined values and all log correctly.
Im guessing Im breaking some angular rules, if anyone could help that would be great.
apiKeyOptions overview:
apiKeyOptions is an array of up to 50 objects
each object is in the form
{
defaultValue: boolean,
description: null,
name: String,
setting: "Default" or Boolean,
value: Boolean
}
Added after comment below:
If I add-
console.log(index);
console.log(apiKeyOptions[index]);
to the function $scope.isUnchanged, I get the expected results
example :
13
Object {name: "LOREM IPSUM", description: null, defaultValue: false, setting: "default", value: falseā€¦}
So index is not always -1. The reason I pass the object to the function and not $index is because of the filter | search so the index will change depending on the search.
FIXED
As shown in the answer below . I was getting a index = -1 error but its was buried in 100's of CORRECT log outputs.
Oddly this did not stop the app from working and I will need to have a deeper look into how ng-disabled is bound to a value. To fix I simply replaced the indexOf with
for (var i = 0; i< $scope.options.length; i++ ){
if($scope.options[i].name == option.name){
var index = i;
}
}

The problem seems to be with the parameter passed to $scope.isUnchanged = function(option) {
Since ng-repeat creates a new scope for each loop, i suspect that the 'option' available to each loop would be a new object and will not have a reference to 'options' array.
<tr ng-repeat="option in options | filter:search">
Therefore your isUnchanged function will receive parameter as a new object and hence below code always returns -1. Because indexOf matches the given argument in the array and since the argument 'option' is an object and doesn't refer(reference comparison) the same element of array hence no match will found. i.e var a = {id:1};var b = [a]; b.indexOf({id:1}) === -1; b.indexOf(a) === 0;
var index = $scope.options.indexOf(option);//always be -1 in your case
// therefore apiKeyOptions[index] will always be undefined
As a workaround you should pass $index to isUnchanged from the view.

Related

removing objects in an object in an array javascript

I've done some research on this issue. I am trying to manipulate an array of calculated values that looks like this in the console:
{nodeVoltages: Array(11), totalPower: Array(1), xlength: Array(11)}
nodeVoltages: Array(11)
0:48
1:47.71306060387108
2:47.250273223993105
3:46.59686907269243
4:45.71876416434013
5:44.53304242029258
6:42.745236969423615
7:Complex {re: 40.38334500994142, im:1.919295696316476, __ember1513267958317: "ember368"}
8:Complex { re:39.55961661806138, im:3.8933604519196416, __ember1513267958317: "ember369"}
This array is created dynamically through some math that I've come up with so there is no input data that I can give you. I'm trying to make the above array look like this:
{nodeVoltages: Array(11), totalPower: Array(1), xlength: Array(11)}
nodeVoltages: Array(11)
0:48
1:47.71306060387108
2:47.250273223993105
3:46.59686907269243
4:45.71876416434013
5:44.53304242029258
6:42.745236969423615
7:40.38334500994142
8:39.55961661806138
Using mathjs, I was able to evaluate my expressions and dynamically add the values into an array with the array.push command and display them. However, my code breaks once the imaginary values pop up in the results of my array.
How can I remove these imaginary numbers from my array? In other words, I need to remove the "im:" parts of the values when they begin to appear before I push them to the displayed array.
I tried to do this with some code I found from a previous answer to someone else's question (How do I remove a particular element from an array in JavaScript?) splice command like this:
var nodeVoltage2 = parser.eval(expression2);
//checks if there are imaginary values and removes them
if ("im" in nodeVoltage2) {
nodeVoltage2.splice(2,1)
}
//adds value to result array for analysis
nodeVoltages.push(nodeVoltage2);
but it returns in the console that "im is not defined".
Any help is greatly appreciated!
You can use the array map function.
Basically, we loop through the array. If the item has a .re property, we take that value only. If there is no .re property, we keep the value as is.
We can either write that in shorthand, as with result using the ternary operator and arrow function, or we can write it in a slightly more verbose but traditional way, as with resultTwo
let data = [
48
,47.71306060387108
,47.250273223993105
,46.59686907269243
,45.71876416434013
,44.53304242029258
,42.745236969423615
,{re: 40.38334500994142, im:1.919295696316476, __ember1513267958317: "ember368"}
,{ re:39.55961661806138, im:3.8933604519196416, __ember1513267958317: "ember369"}
]
let result = data.map((x) => x && x.re ? x.re : x);
let resultTwo = data.map(function(elem) {
// First, we need to check that the array element is not null / undefined
// We then need to check that it has a property called re that is also not null / undefined
if (elem != null && elem.re != null) {
// Just return the property we're interested in
return elem.re;
} else {
// Return the element as is
return elem;
}
});
console.log(result);
console.log(resultTwo);

angular infinite digest loop from ng-model using getterSetter

Here is the html:
<select style="width: 100%;" ng-model="vm.orgType" ng-model-options="{getterSetter: true}" ng-options="orgType as orgType.ORGANIZATION_TYPE for orgType in vm.orgTypes">
</select>
and here is the getter/setter function:
function orgType(selectedType) {
if (arguments.length == 0)
return orgType.selectedOrgType || { ORGANIZATION_TYPE: 'Organization Type', ORGANIZATION_TYPE_ID: null };
orgType.selectedOrgType = selectedType;
if (selectedType.ORGANIZATION_TYPE_ID) {
if (vm.registrant.StakeholderOrgs[0])
vm.registrant.StakeholderOrgs[0] = selectedType.ORGANIZATION_TYPE_ID;
else
vm.registrant.StakeholderOrgs.push(selectedType.ORGANIZATION_TYPE_ID);
}
else
vm.registrant.StakeholderOrgs.splice(0);
}
the following line:
return orgType.selectedOrgType || { ORGANIZATION_TYPE: 'Organization Type', ORGANIZATION_TYPE_ID: null };
throws the infinite digest loop error.
Let me explain what I am trying to do here. I need to push the id onto a list if there is a selection made. I realize that I could just do an ng-model on some variable selectedOrgType and then just put my logic in an ng-change. However, I am trying to make a dropdown that does not create any unnecessary model variables. Instead, I was hoping to just put the logic in a getter/setter, that seems more appropriate to me. One of vm.orgTypes is { ORGANIZATION_TYPE: 'Organization Type', ORGANIZATION_TYPE_ID: null }, I was hoping that would be my default value instead I get this digest error, don't understand where it is coming from.
When you add ng-model attribute, angular add internal watch, that check value on every digest loop, and if value changed - run digest again.
In you case you return object literal. In javascript when you compare two literals, even with same structure - you get false
({a:1} == {a:1}) // false
because this really two different object.
So, when you return object literal in your getter, watch check it with previous value, and, as i say above, if you return literal - get false
So you get your error with infinite digest.
For solving you just need return same object.
If you have this object inside array, like
vm.orgTypes=[
{ ORGANIZATION_TYPE: 'Organization Type', ORGANIZATION_TYPE_ID: null }
];
So you just need use it directly:
return orgType.selectedOrgType || orgTypes[0];
Yer another way: just save default falue to varible and use it
var defaultSelect = { ORGANIZATION_TYPE: 'Organization Type', ORGANIZATION_TYPE_ID: null };
....
function orgType(selectedType) {
if (arguments.length == 0)
return orgType.selectedOrgType || defaultSelect;
In this case you would return same element in default case, so avoid infinite digest loot.

angularjs function failing because of extra $$hashKey

I have the below HTML:
<li ng-click="toggleBeep(beep)" ng-class-odd="'gradient-two'"
ng-class-even="'gradient-three'" ng-repeat="beep in beeps">
<span>{{beep.name}}</span>
<label class="bold" ng-show="isSelected(beep)">selected</label>
</li>
JavaScript (AngularJS):
$scope.beeps = $sounds.getAll();
// get stored beep from localStorage
var notification_beep =
angular.fromJson(localStorage.getItem('notification_beep'));
console.log($scope.beeps[0]);
console.log(notification_beep);
// handle change sound on click event
$scope.toggleBeep = function (beep) {
$cbSounds.play(beep.file);
$scope.selected = beep;
localStorage.setItem('notification_beep', angular.toJson(beep));
};
$scope.isSelected = function (beep) {
return $scope.selected === beep;
};
Now, when I click on any li I get the selected label is shown because of the $scope.isSelected function. However, when I try to add this line $scope.selected = notification_beep which is the beep object stored in the localStorage the label is not shown and I get the below return values.
The only difference I could spot is that $$hashkey is present on $scope.beeps[0] while it's not on notification_beep. Could this be the cause? Thanks.
The following comparison:
$scope.selected === beep
Will only return true if the two variables reference the same object.
The following line will create a new object:
var notification_beep = angular.fromJson(localStorage.getItem('notification_beep'));
So it will not reference the same object as $scope.selected.
To clarify, this will return false: { name: 'Beep 1' } === { name: 'Beep 1' }
The simplest solution is to instead compare against a unique primtive of the objects.
For example:
return $scope.selected.name === beep.name;
The $$hashkey property is inserted into the object by ng-repeat and is used to track which object corresponds to which DOM template. The reason it doesn't exist in notification_beep is because angular.toJson removes the property from the object.

Angularjs filtering over array of objects in ngRepeat doesn't restore items with empty search property

Please, consider the following example:
Template:
<body ng-controller="MainCtrl">
Search: <input ng-model="search.$" ><br>
Search by tag: <input ng-model="search.tag" >
<p ng-repeat="item in items | filter:search">
<span>{{item.content}}</span> <span>{{item.tag}}</span>
</p>
</body>
Script:
app.controller('MainCtrl', function ($scope, $filter, filterFilter) {
$scope.items = [
{content:'3333113', tag:['a','b','c']},
{content:'111111g', tag:['b','c','d']},
{content:'345345', tag:[]},
{content:'2221122', tag:['c','d','e']},
{content:'2221122', tag:[]},
{content:'333', tag:[]}
];
});
When searching via the first input ng-model="search.$" with any data everything is Ok.
When searching via the seond input ng-model="search.tag" search does work by tags like a, b, but when it is cleared the restored array lacks the items which had empty search value, e.g. {content:'2221122', tag:[]} in this example.
jsBin example
Why does it happen ? Is there an easy way to avoid it ?
Short answer:
here is a working code: http://jsbin.com/AwunOyAt/2
You need a directive to make search.tag undefined when it's empty:
Directive:
app.directive('modelUndefined', function(){
return {
require: 'ngModel',
link: function(scope,elm,attrs,ngModel){
ngModel.$parsers.push(function(val){
return val === "" ? undefined : val;
});
}
}
});
html:
<input ng-model="search.tag" model-undefined>
Long answer:
From the docs of filter:filter:
In HTML Template Binding
{{ filter_expression | filter:expression:comparator }}
Parameters#expression
Object: A pattern object can be used to filter specific properties on objects contained by array. For example {name:"M", phone:"1"} predicate will return an array of items which have property name containing "M" and property phone containing "1". A special property name $ can be used (as in {$:"text"}) to accept a match against any property of the object. That's equivalent to the simple substring match with a string as described above.
As you can see, the filter expression can be an object with more then one predicates.
how to trace it?
Initially ngModel won't set search.tag until there is an input so it's still undefined.
First I pass an input into search.$, the search object looks like so:
$scope.search = {
'$' : 'something'
}
Then I'll pass something into search.tag, the search object:
$scope.search = {
'$' : 'something',
'tag': 'anything'
}
But when I clear it then the search object still have the tag property
$scope.search = {
'$' : 'something',
'tag': ''
}
filter:filter filters based on both predicates, this is the source code:
case "object":
// jshint +W086
for (var key in expression) {
(function(path) {
if (typeof expression[path] == 'undefined') return;
predicates.push(function(value) {
return search(path == '$' ? value : (value && value[path]), expression[path]);
});
})(key);
In our case the expression is the search object , and the paths are $ and tag.
See this line: if (typeof expression[path] == 'undefined') return;
If we set search.tag = undefined , the filter ignores it.
But If we set search.tag = '' this tag path is added to the predicates check array.
How to enforce ngModel to make search.tag undefined when it's empty?
See the directive above, you need to use ngModelController#$parsers to change the way the view value is converted when it updates the model.
I do not know if it helps but I put in the following:
<p>{{search.tag == undefined}}</p>
It then showed that initially it is undefined und later on it is an empty string (if you empty the input). The search results then kind of make sense.
Looks like there is a change in AngularJS version 1.2.10. Using https://ajax.googleapis.com/ajax/libs/angularjs/1.0.2/angular.min.js does not eliminate empty entries.

javascript compare objects in array

I have a grid of pictures on a page. And, periodically, I want to randomly swap one out for one of 50 I have in an array of Objects- but only if they're not already in the grid. This last part is what my code is failing to do.
I first get all 50 items, and put them into an allmedia array:
// initialize
var allmedia = getAllMedia();
var imagesInGrid = [];
When I place the items in the grid, I add to an array of grid items:
imagesInGrid.push(allmedia [i]); // while looping to fill DOM grid
Then, every 8 seconds I run a getRandomImage() routine that randomly gets an image from the allmedia array and then tests it to see if it's not already in the DOM.
function getRandomImageNotInGrid(){
var randomNumber = Math.floor(Math.random() * allmedia.length);
if (!isInArray(allmedia[randomNumber], imagesInGrid)) {
return allmedia[randomNumber];
} else {
return getRandomImageNotInGrid();
}
}
function isInArray(item, arr) {
if(arr[0]===undefined) return false;
for (var i=arr.length;i--;) {
if (arr[i]===item) {
return true;
}
}
return false;
}
But when I step through the code the (arr[i]===item) test is failing. I can see that the two objects are exactly the same, but the === isn't seeing this as true.
Is this a ByReference / ByValue issue? What am I doing wrong?
console.log:
arr[i]===item
false
arr[i]==item
false
typeof item
"object"
typeof arr[i]
"object"
Edit::
In the output below, I don't understand why arr[0] is not the same as 'item'. I use the exact same object that I put into allmedia as I do when I place the item into the page and, accordingly update imagesInGrid.
console.dir(arr[0]);
Object
caption: Object
comments: Object
created_time: "1305132396"
filter: "Poprocket"
id: "69204668"
images: Object
likes: Object
link: "http://instagr.am/p/EH_q8/"
location: Object
tags: Array[2]
type: "image"
user: Object
__proto__: Object
console.dir(item);
Object
caption: Object
comments: Object
created_time: "1305132396"
filter: "Poprocket"
id: "69204668"
images: Object
likes: Object
link: "http://instagr.am/p/EH_q8/"
location: Object
tags: Array[2]
type: "image"
user: Object
__proto__: Object
Instead of randomly selecting one from allmedia, can you instead remove one from allmedia?
var randomNumber = Math.floor(Math.random() * allmedia.length);
imagesInGrid.push(allmedia.splice(randomNumber,1));
When you use ===, you are comparing the objects by reference. What type of objects are you using to compare? Are you sure they are the same object reference? For example, if you are using strings, you may want to use == instead of ===. If you are using DOM objects, you will want to compare the source, as Alxandr suggested.
Also, your for loop syntax appears to be wrong:
for (var i=arr.length;i--;)
Should be:
for (var i=arr.length - 1; i >= 0; i--)
...if I'm not mistaken.
You don't show any code for how the image "objects" are created or how they are added and removed from the DOM. If you are creating image elements and storing references in an array, then replacing the DOM element with the one from the array, then the comparision should work.
However, if your image object is a bundle of data that is used to create an image element for display, then they will never be equal to each other. Every javascript object is unique, it will only ever be equal to itself.
But I suspect the simplest solution is that suggested by ic3b3rg - remove the object from allMedia when you select it, that way you don't have to test if it's already in imagesInGrid because you can only select each image once. If you want the display to go on forever, then when allmedia is empty, put all the images from imagesInGrid back into it and start again.
Edit
Your problem is the for loop. When you set :
for (var i=arr.length;i--;) {
// On first iteration, i=arr.length
// so arr[i] is undefined
}
i is not decremented until after the first loop, so set i=arr.length-1. It is more common to use while with a decrementing counter:
var i = arr.length;
while (i--) {
// i is decremented after the test
}

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