<q-checkbox
v-model=“formData.checks.options[].id
/>
Return data:
formData: {
checks:
[{
options:
[{
id: 1
},
{
id: 2
}]
},
{
options:
[{
id: 1
},
{
id: 2
}]
}]
}
Question -1: In the above scenario, I need to loop through multiple checks with their respective options. Is it a good practice to do two for loops. Say for example, one to loop all checks and second to loop all options with loop 1 index?
Question -2: if I want to check default values for a specific checks list with respective it’s respective option. How can I do it?
Related
I'm trying to understand why Javascript array sort doesn't work with the following logic. I have no problems making my own algorithm to sort this array, but I'm trying to make it with the Javascript sort built-in method to understand it better.
In this code, I want to push entities that "belongs to" another entity to the bottom, so entities that "has" other entities appear on the top. But apparently, the sort method doesn't compare all elements with each other, so the logic doesn't work properly.
Am I doing something wrong, or it is the correct behavior for the Javascript sort method?
The code I'm trying to execute:
let entities = [
{
name: 'Permission2',
belongsTo: ['Role']
},
{
name: 'Another',
belongsTo: ['User']
},
{
name: 'User',
belongsTo: ['Role', 'Permission2']
},
{
name: 'Teste',
belongsTo: ['User']
},
{
name: 'Role',
belongsTo: ['Other']
},
{
name: 'Other',
belongsTo: []
},
{
name: 'Permission',
belongsTo: ['Role']
},
{
name: 'Test',
belongsTo: []
},
]
// Order needs to be Permission,
let sorted = entities.sort((first, second) => {
let firstBelongsToSecond = first.belongsTo.includes(second.name),
secondBelongsToFirst = second.belongsTo.includes(first.name)
if(firstBelongsToSecond) return 1
if(secondBelongsToFirst) return -1
return 0
})
console.log(sorted.map(item => item.name))
As you can see, "Role" needs to appear before "User", "Other" before "Role", etc, but it doesn't work.
Thanks for your help! Cheers
You're running into literally how sorting is supposed to work: sort compares two elements at a time, so let's just take some (virtual) pen and paper and write out what your code is supposed to do.
If we use the simplest array with just User and Role, things work fine, so let's reduce your entities to a three element array that doesn't do what you thought it was supposed to do:
let entities = [
{
name: 'User',
belongsTo: ['Role', 'Permission2']
},
{
name: 'Test',
belongsTo: []
},
{
name: 'Role',
belongsTo: ['Other']
}
]
This will yield {User, Test, Role} when sorted, because it should... so let's see why it should:
pick elements [0] and [1] from [user, test, role] for comparison
compare(user, test)
user does not belong to test
test does not belong to user
per your code: return 0, i.e. don't change the ordering
we slide the compare window over to [1] and [2]
compare(test, role)
test does not belong to role
role does not belong to test
per your code: return 0, i.e. don't change the ordering
we slide the compare window over to [2] and [3]
there is no [3], we're done
The sorted result is {user, test, role}, because nothing got reordered
So the "bug" is thinking that sort compares everything-to-everything: as User and Role are not adjacent elements, they will never get compared to each other. Only adjacent elements get compared.
Lets say I have the following list in data:
data: {
todos: [
{ id: 1, title: "Learn Python" },
{ id: 2, title: "Learn JS" },
{ id: 3, title: "Create WebApp" }
]
}
Now I want to pass only the entry with id of 2 to the prop:
<dynamic-prop :id=todos[2] :title="todos.title"> </dynamic-prop>
Is something like that possible in Vue?
Sure, you can pass any data on. Just don't forget to add quotation marks and mind the off-by-one problem. So if you want to pass the second element in a (zero-indexed) array, you'd write something like:
<dynamic-prop :id="todos[1].id" :title="todos[1].title"> </dynamic-prop>
I am generating comboboxes dynamically and I need to pass a different collection to the ng-repeat every time.How can I do that?
<div ng-repeat="choice in $ctrl.inputFilterRows">
<md-select ng-model="choice.name">
<md-option ng-repeat="filter in $ctrl.filters" value="{{filter.value}}" >
{{filter.value}}
</md-option>
</md-select>
</div>
Tried to set from the controller, but didnt work:
self.inputFilterRows[0].filters = [{ value: 'June' }, { value: 'July' }, { value: 'August' }];
An idea would be to use ng-if on several md-select elements and decide which one to enable based on a condition that suits you.
Another is to have a $scope variable that is linked to a single ng-repeat select, but you keep assigning new values to that $scope variable collection whenever you want. That would force a scope redraw and the ng-repeat would now use the new collection values.
Second one is probably cleaner.
EDIT:
Based on a better explanation provided in the comments below I now realise that you want a set of selects, each with their own set of options.
To achieve something like that I would suggest having an array of arrays, in which each object would represent a select, and then it's contents would be the options for that select.
$scope.selectArray = [
{ name: 'colours', filters: [{ value: 'black' }, { value: 'red' }, { value: 'blue' }] },
{ name: 'months', filters: [{ value: 'January' }, { value: 'February' }, { value: 'March' }] }
];
Now, you can have an ng-repeat iterating over selectArray (select in selectArrays) to create the selects, and then each one would contain another ng-repeat to iterate over the select.filters (filter in select.filters)
I am not going to write the exact code because you look like you know what you're doing and I'm sure you can put it together yourself very easily.
If you want to change the dataset of a specific select you can do something like:
$scope.selectArray[1].filters[0].value = 'December';
or
$scope.selectArray[1].filters = [{ value: 'June' }, { value: 'July' }, { value: 'August' }];
Question
I'm interested in the properties of $$hashkey on angular arrays/objects.
Would each generated hashkey be the same each time you reload a
page; a quick test tells me yes but I somewhat assumed it
wouldn't?
If you updated/added to the existing array, would the old hashkey's
stay consistent?
If the above is true, is there a way to fetch from an array using
the hashkey? - of cause I could roll my own but before I recreate the wheel I thought I'd ask.
Example:
Views would include:
form data (example has 1 form)
element data (example has 2 elements)
element options data (example has 2 options per element)
Fetch method:
angular.get($$hashkey);
You would then pass the hashkey of the element and it would return a reference to that array inside the full array.
Lastly the data would be:
{
form_id: 1
form_desc: 'xxx',
form_name: 'name 1',
Elements: [
{
element_id: 1,
element_name: 'element1',
default_value: null,
disabled: "0",
element_type: "image",
ElementOptions: [
{
show: false,
sort_order: 0,
value: "ar",
},
{
show: true,
sort_order: 1,
value: "rw",
}
],
},
{
element_id: 2,
element_name: 'element2',
default_value: null,
disabled: "0",
element_type: "image",
ElementOptions: [
{
show: false,
sort_order: 0,
value: "ar",
},
{
show: true,
sort_order: 1,
value: "rw",
}
],
}
]
}
$$hashkeys will only be computed for functions and objects so if you wish to track anything that isn't one of those types then you have that limitation.
$$Hashkeys look like ...
(function||object): N
...
Where N is just an incremental value being adjusted + 1 for each $$HashKey computed.
So, in many cases this could be the same value across page loads. But loading data that is asynch, will cause differences when multiple data sources are being queried as part of page initialization and order of return cannot be guranteed. In cases like that you would have to marshall all your asynch data and then assign that data to your scope in a specific order to ensure consistent $$hashkeys.
Moving items around in an array that is linked to our DOM (via ng-repeat) will not change that items $$hashkey. Deleting it and re-adding it will.
I would not use $$Hashkey for my own housekeeping as it is intended to be internal to AngularJS.
I've used this internal private property when I had no identifiers.
I think, it's pretty usable, but not recommended.
I'm working with AngularJS and have an object array like that in my controller :
$scope.folderList = [{
name: 'root',
path: 'uploads/',
subs: [{
name: 'pictures',
path: 'uploads/pictures',
subs: [{
...
}]
}, {
name: 'videos',
path: 'uploads/videos',
subs: [{
...
}]
}]
}];
For this nested array, I have 2 directives set them up in a nested UL LI list with ng-repeat.
Now I have my nested list of folders, and I want to trigger a function to delete the selected folder.
So I trigger my function to delete with "folder" in parameter, for example, if I trigger the "delete" function on the pictures folder, the folder parameter will be like that :
folder = {
name: 'pictures',
path: 'uploads/pictures',
subs: [{ ... }]
}
And I want to delete this object from the nested array.
With a 1 level object array, I use this :
var index = $scope.folderList.indexOf(folder);
delete $scope.folderList.splice(index, 1);
But it (obviously) doesn't work on a nested array !
How can I easily delete an entry from a nested array on JavaScript (or AngularJS ?)
I've heard that underscore.js was made for this, but I never used it, and after seeing their documentation I wasn't able to find the proper function to do this !
Thanks for your help !