Vue.js Retrieving Remote Data for Options in Select2 - ajax

Question

I'm working on a project that is using Vue.js and Vue Router as the frontend javascript framework that will need to use a select box of users many places throughout the app. I would like to use select2 for the select box. To try to make my code the cleanest I can, I've implemented a custom filter to format the data the way select2 will accept it, and then I've implemented a custom directive similar to the one found on the Vue.js website.
When the app starts up, it queries the api for the list of users and then stores the list for later use. I can then reference the users list throughout the rest of the application and from any route without querying the backend again. I can successfully retrieve the list of users, pass it through the user list filter to format it the way that select2 wants, and then create a select2 with the list of users set as the options.
But this works only if the route that has the select2 is not the first page to load with the app. For example, if I got to the Home page (without any select2 list of users) and then go to the Users page (with a select2), it works great. But if I go directly to the Users page, the select2 will not have any options. I imagine this is because as Vue is loading up, it sends a GET request back to the server for the list of users and before it gets a response back, it will continues with its async execution and creates the select2 without any options, but then once the list of users comes back from the server, Vue doesn't know how to update the select2 with the list of options.
Here is my question: How can I retrieve the options from an AJAX call (which should be made only once for the entire app, no matter how many times a user select box is shown) and then load them into the select2 even if the one goes directly to the page with the select2 on it?
Thank you in advance! If you notice anything else I should be doing, please tell me as I would like this code to use best practices.
Here is what I have so far:
Simplified app.js
var App = Vue.extend({
ready: function() {
this.fetchUsers();
},
data: function() {
return {
globals: {
users: {
data: []
},
}
};
},
methods: {
fetchUsers: function() {
this.$http.get('./api/v1/users/list', function(data, status, response) {
this.globals.users = data;
});
},
}
});
Sample response from API
{
"data": [
{
"id": 1,
"first_name": "John",
"last_name": "Smith",
"active": 1
},
{
"id": 2,
"first_name": "Emily",
"last_name": "Johnson",
"active": 1
}
]
}
User List Filter
Vue.filter('userList', function (users) {
if (users.length == 0) {
return [];
}
var userList = [
{
text : "Active Users",
children : [
// { id : 0, text : "Item One" }, // example
]
},
{
text : "Inactive Users",
children : []
}
];
$.each( users, function( key, user ) {
var option = { id : user.id, text : user.first_name + ' ' + user.last_name };
if (user.active == 1) {
userList[0].children.push(option);
}
else {
userList[1].children.push(option);
}
});
return userList;
});
Custom Select2 Directive (Similar to this)
Vue.directive('select', {
twoWay: true,
bind: function () {
},
update: function (value) {
var optionsData
// retrive the value of the options attribute
var optionsExpression = this.el.getAttribute('options')
if (optionsExpression) {
// if the value is present, evaluate the dynamic data
// using vm.$eval here so that it supports filters too
optionsData = this.vm.$eval(optionsExpression)
}
var self = this
var select2 = $(this.el)
.select2({
data: optionsData
})
.on('change', function () {
// sync the data to the vm on change.
// `self` is the directive instance
// `this` points to the <select> element
self.set(select2.val());
console.log('emitting "select2-change"');
self.vm.$emit('select2-change');
})
// sync vm data change to select2
$(this.el).val(value).trigger('change')
},
unbind: function () {
// don't forget to teardown listeners and stuff.
$(this.el).off().select2('destroy')
}
})
Sample Implementation of Select2 From Template
<select
multiple="multiple"
style="width: 100%"
v-select="criteria.user_ids"
options="globals.users.data | userList"
>
</select>

Answer 1

I may have found something that works alright, although I'm not sure it's the best way to go about it. Here is my updated code:
Implementation of Select2 From Template
<select
multiple="multiple"
style="width: 100%"
v-select="criteria.reporting_type_ids"
options="globals.types.data | typeList 'reporttoauthorities'"
class="select2-users"
>
</select>
Excerpt from app.js
fetchUsers: function() {
this.$http.get('./api/v1/users/list', function(data, status, response) {
this.globals.users = data;
this.$nextTick(function () {
var optionsData = this.$eval('globals.users.data | userList');
console.log('optionsData', optionsData);
$('.select2-users').select2({
data: optionsData
});
});
});
},
This way works for me, but it still kinda feels hackish. If anybody has any other advice on how to do this, I would greatly appreciate it!

Answer 2

Thanks but I'm working on company legacy project, due to low version of select2, I encountered this issue. And I am not sure about the v-select syntax is from vue standard or not(maybe from the vue-select libaray?). So here's my implementation based on yours. Using input tag instead of select tag, and v-model for v-select. It works like a charm, thanks again #bakerstreetsystems
<input type="text"
multiple="multiple"
style="width: 300px"
v-model="supplier_id"
options="suppliers"
id="select2-suppliers"
>
</input>
<script>
$('#app').ready(function() {
var app = new Vue({
el: "#app",
data: {
supplier_id: '<%= #supplier_id %>', // We are using server rendering(ruby on rails)
suppliers: [],
},
ready: function() {
this.fetchSuppliers();
},
methods: {
fetchSuppliers: function() {
var self = this;
$.ajax({
url: '/admin_sales/suppliers',
method: 'GET',
success: function(res) {
self.suppliers = res.data;
self.$nextTick(function () {
var optionsData = self.suppliers;
$('#select2-suppliers').select2({
placeholder: "Select a supplier",
allowClear: true,
data: optionsData,
});
});
}
});
},
},
});
})
</script>