I wanted to ask if there is any way to make a dropdown menu in react using .map() and .filter(),
like for instance let's say that i have this file :
Data.js
export const NavigationMenu = [
{
id: 1,
title: "header item 1",
},
{
id: 2,
title: "header item 2",
}
];
export const NavigationDropMenu = [
{
id: 1,
title: "drop item 1",
parent: "header item 1",
},
{
id: 2,
title: "drop item 1",
parent: "header item 2",
}
];
what i want to do is to first map the items from the first list like this
<li className="header__menu__item">
{item.title}
</li>
))}
and inside of that i want to make another map for the dropmenu, which will fetch items from the second list but to use filter to show only elements that contain that element as a trait.
so to make it simpler, I want to know if it is possible to make a dropdown menu using .map() and .filter().
thank you.
I am working on an SPA application where I have a list of data variables that are used as the <option> tags in the dropdown. I want to navigate to another page on the #change event of the dropdown therefore I want to use either the id or name of the select command as the name of the data property. Here is what I mean:
Here is what I have in the data function:
data(){
return {
participants: [
{ value: 0, linkText: '', linkTerm: 'Select' },
{ value: 1, linkText: '/meetings/participants/create', linkTerm: 'Add New' },
{ value: 2, linkText: '/meetings/participants', linkTerm: 'All Participants' },
],
positions: [
{ value: 0, linkText: '', linkTerm: 'Select' },
{ value: 1, linkText: '/meetings/positions/create', linkTerm: 'Add New' },
{ value: 2, linkText: '/meetings/positions', linkTerm: 'All Positions' },
],
}
}
Here is the select tag where I use the above data variables as the <option> tag:
<select name="participants" id="participants" class="select-field" #change="changeRoute($event)">
<option v-for="p in participants" :value="p.value">{{ p.linkTerm }}</option>
</select>
Now I want to have one function changeRoute($event) from which I will navigate to different pages, therefore I want to use the id or name value as the data property, here is the function:
methods:{
changeRoute($event){
var name = $event.target.name;
var value = document.getElementById($event.target.id).value;
}
}
Here in the above function I want to use the name as the data property as below:
I want to write this:
this.name[value].linkText;
And because name here is the name of the tag which is actually participants so the above line of code should mean something like this:
this.participants[value].linkText
And that should return the linkText of the participants object of the data function.
Any help is appreciated in advance.
Change the below line
this.name[value].linkText;
to
this[name][value].linkText;
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 have this array:
myArray: [{
name: "Name1",
subArray: [{
name: "Subname1",
value: 1
}]
}, {
name: "Name2",
subArray: [{
name: "Subname2",
value: 2
}]
}, {
name: "Name3",
subArray: [{
name: "Subname3",
value: 3
}, {
name: "Subname4",
value: 4
}]
}, ]
I am using this array in a Vue app, but this should not be vue-specific.
In a dropdown I am showing all the values from the parent array (Name1, Name2, Name3). So far, so good. In Vue I do it like so:
<option v-for="array in myArray">
But, when the user has selected the parent array, I have another dropdown below, which should show the children of the selected object. So if the user selects Name3, there should be two options in my other dropdown with the two subArray's values.
How can I achive this?
Try using
<option v-for="option in myArray[index].subArray">
where index is index of your first option.
Description
I have a small product order system, where a user can add order lines, and on each order line add one or more products. (I realise it's quite unusual for more than one product to be on the same order line, but that's another issue).
The products that can be selected on each line is based on a hierarchy of products. For example:
Example product display
T-Shirts
V-neck
Round-neck
String vest
JSON data
$scope.products = [
{
id: 1,
name: 'T Shirts',
children: [
{ id: 4, name: 'Round-neck', children: [] },
{ id: 5, name: 'V-neck', children: [] },
{ id: 6, name: 'String vest (exclude)', children: [] }
]
},
{
id: 2,
name: 'Jackets',
children: [
{ id: 7, name: 'Denim jacket', children: [] },
{ id: 8, name: 'Glitter jacket', children: [] }
]
},
{
id: 3,
name: 'Shoes',
children: [
{ id: 9, name: 'Oxfords', children: [] },
{ id: 10, name: 'Brogues', children: [] },
{ id: 11, name: 'Trainers (exclude)', children: []}
]
}
];
T-Shirts isn't selectable, but the 3 child products are.
What I'm trying to achieve
What I'd like to be able to do, is have a 'select all' button which automatically adds the three products to the order line.
A secondary requirement, is that when the 'select all' button is pressed, it excludes certain products based on the ID of the product. I've created an 'exclusion' array for this.
I've set up a Plunker to illustrate the shopping cart, and what I'm trying to do.
So far it can:
Add / remove order lines
Add / remove products
Add a 'check' for all products in a section, excluding any that are in the 'exclusions' array
The problem
However, although it adds the check in the input, it doesn't trigger the ng-change on the input:
<table class="striped table">
<thead>
<tr>
<td class="col-md-3"></td>
<td class="col-md-6"></td>
<td class="col-md-3"><a ng-click="addLine()" class="btn btn-success">+ Add order line</a></td>
</tr>
</thead>
<tbody>
<tr ng-repeat="line in orderHeader.lines">
<td class="col-md-3">
<ul>
<li ng-repeat="product in products" id="line_{{ line.no }}_product_{{ product.id }}">
{{ product.name }} <a ng-click="selectAll(product.id, line.no)" class="btn btn-primary">Select all</a>
<ul>
<li ng-repeat="child in product.children">
<input type="checkbox"
ng-change="sync(bool, child, line)"
ng-model="bool"
data-category="{{child.id}}"
id="check_{{ line.no }}_product_{{ child.id }}"
ng-checked="isChecked(child.id, line)">
{{ child.name }}
</li>
</ul>
</li>
</ul>
</td>
<td class="col-md-6">
<pre style="max-width: 400px">{{ line }}</pre>
</td>
<td class="col-md-3">
<a ng-click="removeLine(line)" class="btn btn-warning">Remove line</a>
</td>
</tr>
</tbody>
</table>
Javascript
$scope.selectAll = function(product_id, line){
target = document.getElementById('line_'+line+'_product_'+product_id);
checkboxes = target.getElementsByTagName('input');
for (var i = 0; i < checkboxes.length; i++) {
if (checkboxes[i].type == 'checkbox') {
category = checkboxes[i].dataset.category;
if($scope.excluded.indexOf(parseInt(category)) == -1)
{
checkboxes[i].checked = true;
// TODO: Check the checkbox, and set its bool parameter to TRUE
}
}
}
}
Update with full solution
There were a couple of issues with the above code. Firstly, I was trying to solve the problem by manipulating the DOM which is very much against what Angular tries to achieve.
So the solution was to add a 'checked' property on the products so that I can track if they are contained on the order line, and then the view is updated automatically.
One drawback of this method is that the payload would be significantly larger (unless it is filtered before being sent to the back-end API) as each order line now has data for ALL products, even if they aren't selected.
Also, one point that tripped me up was forgetting that Javascript passes references of objects / arrays, not a new copy.
The solution
Javascript
var myApp = angular.module('myApp', []);
myApp.controller('CartForm', ['$scope', function($scope) {
var inventory = [
{
id: 1,
name: 'T Shirts',
checked: false,
children: [
{ id: 4, name: 'Round-neck', checked: false, children: [] },
{ id: 5, name: 'V-neck', checked: false, children: [] },
{ id: 6, name: 'String vest (exclude)', checked: false, children: [] }
]
},
{
id: 2,
name: 'Jackets',
checked: false,
children: [
{ id: 7, name: 'Denim jacket', checked: false, children: [] },
{ id: 8, name: 'Glitter jacket', checked: false, children: [] }
]
},
{
id: 3,
name: 'Shoes',
checked: false,
children: [
{ id: 9, name: 'Oxfords', checked: false, children: [] },
{ id: 10, name: 'Brogues', checked: false, children: [] },
{ id: 11, name: 'Trainers (exclude)', checked: false, children: []}
]
}
];
$scope.debug_mode = false;
var products = angular.copy(inventory);
$scope.orderHeader = {
order_no: 1,
total: 0,
lines: [
{
no: 1,
products: products,
total: 0,
quantity: 0
}
]
};
$scope.excluded = [6, 11];
$scope.addLine = function() {
var products = angular.copy(inventory);
$scope.orderHeader.lines.push({
no: $scope.orderHeader.lines.length + 1,
products: products,
quantity: 1,
total: 0
});
$scope.loading = false;
}
$scope.removeLine = function(index) {
$scope.orderHeader.lines.splice(index, 1);
}
$scope.selectAll = function(product){
angular.forEach(product.children, function(item){
if($scope.excluded.indexOf(parseInt(item.id)) == -1) {
item.checked=true;
}
});
}
$scope.removeAll = function(product){
angular.forEach(product.children, function(item){
item.checked=false;
});
}
$scope.toggleDebugMode = function(){
$scope.debug_mode = ($scope.debug_mode ? false : true);
}
}]);
Click here to see the Plunker
You are really over complicating things first by not taking advantage of passing objects and arrays into your controller functions and also by using the DOM and not your data models to try to update states
Consider this simplification that adds a checked property to each product via ng-model
<!-- checkboxes -->
<li ng-repeat="child in product.children">
<input ng-model="child.checked" >
</li>
If it's not practical to add properties to the items themselves, you can always keep another array for the checked properties that would have matching indexes with the child arrays. Use $index in ng-repeat for that
And passing whole objects into selectAll()
<a ng-click="selectAll(product,line)">
Which allows in controller to do:
$scope.selectAll = function(product, line){
angular.forEach(product.children, function(item){
item.checked=true;
});
line.products=product.children;
}
With angular you need to always think of manipulating your data models first, and let angular manage the DOM
Strongly suggest reading : "Thinking in AngularJS" if I have a jQuery background?
DEMO
Why ng-change isn't fired when the checkbox is checked programatically?
It happens because
if($scope.excluded.indexOf(parseInt(category)) == -1)
{
checkboxes[i].checked = true;
// TODO: Check the checkbox, and set its bool parameter to TRUE
}
only affects the view (DOM). ng-change works alongside ngModel, which can't be aware that the checkbox really changed visually.
I suggest you to refer to the solution I provided at How can I get angular.js checkboxes with select/unselect all functionality and indeterminate values?, works with any model structure you have (some may call this the Angular way).