Develop Reference

Bootstrap-vue - Setting table variant dynamically

So I'm using Bootstrap Vue with this test app. I'm trying to change the variant of a table cell depending on the value of it. Unfortunately, the variant parameter will not take a function, so I'm out of ideas on how to achieve this.
This is my code:
var app = new Vue({
el: '#app',
data: {
items: [], //Will be populated through AJAX
fields: [
{
key: 'Vendedor',
label: 'Vendedor'
},
{
key: 'OBJETIVO',
label: 'Objetivo',
formatter: (value) => { return parseFloat(value).toFixed(2)},
variant: estiloObjetivo //THIS IS NOT WORKING
}
]
},
methods: {
Cargar: function () {
var salesperson = getCookie('salespersonCode');
var url_servicio = 'http://MywebService/';
var self = this;
$.ajax({
type: 'GET',
url: url_servicio + 'ventas/' + salesperson,
dataType: "json", // data type of response
success: function(data){
self.items = data
}
});
},
estiloObjetivo (value) {
if value > 0 //I need my cell variant to change depeding on this value
return 'danger'
else
return 'success'
}
}
})
This is my HTML part:
<div id="app">
<button v-on:click="Cargar">Cargar</button>
<b-table striped hover :fields="fields" :items="items"></b-table>
</div>
Any ideas on how to style a Bootstrap-vue cell dynamically?
This is the way it's done in the docs, it's actually set in the "items" array, but how is this useful in cases like mine where I get the data from a web service?:
{
salesperson: 'John',
Objetivo: 2000,
_cellVariants: { salesperson: 'success', Objetivo: 'danger'}
},
So I guess what I need is a way to set the I need is to set the _cellVariants parameter of each element in the 'items' array.

You likely need a computed property. Computed properties automatically update on changes to the reactive variables that they depend on.
The following example implements a computed property, styledItems, which you must use in place of items in the template. It returns a 1-deep copy of items, i.e. a new array containing a copy of each item, with the extra _cellVariants property added.
new Vue({
data: {
items: [ /* your data here */ ]
},
methods: {
estiloObjetivo: value => (value > 0) ? 'danger' : 'success'
},
computed: {
styledItems() {
return this.data.map(datum =>
Object.assign({}, datum, {
_cellVariants: {
Objetivo: this.estiloObjetivo(datum.Objetivo)
}
})
}
})

If you want to add variant to items you could use a computed property called cptItems and define it as follows:
computed:{
cptItems(){
return this.items.map((item)=>{
let tmp=item;
item.OBJETIVO>0?tmp.variant='danger':tmp.variant='success';
return tmp;
})
}
and use that property inside your template like :
<b-table .... :items="cptItems"></b-table>

I was sure the answers above would solve my own issue but they did not. I found a different way to color table cells: https://github.com/bootstrap-vue/bootstrap-vue/issues/1793
This is aside from using variants to color a table cell. Instead, we utilize tdclass and a function.
<script>
new Vue({
el: '#itemView',
data() {
return {
fields: [
{
key: 'Objetive',
sortable: true,
thClass: 'text-nowrap',
tdClass: (value, key, item) => {
return 'table-' + this.getColor(item);
}
}
],
};
},
methods: {
getColor(item) {
return item.Objetive > 0 ? 'danger' : 'success';
},
},
});
</script>
For my own use-case, I needed to compare two cells of the same row, then apply a class to one.
...
{
key: 'DEMAND_QTY',
sortable: true,
thClass: 'text-nowrap',
tdClass: (value, key, item) => {
return 'table-' + this.demandStatusColor(item);
},
},
{ key: 'TOTAL_DEMAND', sortable: true, thClass: 'text-nowrap' },
],
};
},
methods: {
demandStatusColor(item) {
return item.DEMAND_QTY < item.TOTAL_DEMAND ? 'danger' : 'success';
},
}
...
Perhaps this will help someone, if not OP.

#John answer worked for me. I don't have enough reputation to make comment or useful
tdClass: (type, key, item) => {
switch (type) {
case "value":
return "bg-warning text-white";
break;
case "value":
return "bg-danger text-white";
break;
case "value":
return "bg-info text-white";
break;
default:
break;
}
},

Array of functions - Javascript

I'm developing a vue-based system, and for my tables, I'm using this: https://github.com/matfish2/vue-tables-2
The component has lots of options. There's the possibility to define custom cell templates to manipulate data before showing them, like this one for the "created_at" column:
templates: {
created_at(h, row) {
return this.formatDate(row.created_at);
},
//(...)
}
I can add other templates as well:
var user_id = function(h,row){return row.id};
...
templates: {
created_at(h, row) {
return this.formatDate(row.created_at);
},
user_id,
(...) // etc
}
But I'd like to group the functions into a variable, so I could reuse the code, like:
var custom_template = [
{ user_id(h,row){return row.id} },
{ user_name(h,row){return row.name} },
{ created_at(h, row){return this.formatDate(row.created_at)} }
];
templates: {
custom_templates
}
EDIT 1:
So i could have something like:
templates: {
user_id(h,row){return row.id} ,
user_name(h,row){return row.name} ,
created_at(h, row){return this.formatDate(row.created_at)}
}
It's not working, but is it possible? Do I need extra code to achieve this?
Thanks! =)

var custom_template = [
function user_id(h, row) {
return row.id;
},
function user_name(h, row) {
return row.name;
},
function created_at(h, row) {
return row.created_at;
}
];
custom_template.forEach(
item => console.log(item(1, {
id: 1,
name: "test",
created_at: new Date()
})));

You need to combine Igor's solution to create array of functions with some form of expanding the array, such as the spread syntax

Knockout.js Adding a Property to Child Elements

My code doesn't create a new property under the child element of knockout viewmodel that is mapped by knockout.mapping.fromJS.
I have:
//model from Entity Framework
console.log(ko.mapping.toJSON(model));
var viewModel = ko.mapping.fromJS(model, mappingOption);
ko.applyBindings(viewModel);
console.log(ko.mapping.toJSON(viewModel));
The first console.log outputs:
{
"Id": 0,
"CurrentUser": {
"BoardIds": [
{
"Id": 0
}
],
"Id": 1,
"UserName": "foo",
"IsOnline": true
},
"Boards": []
}
And then the mappingOption is:
var mappingOption = {
create: function (options) {
var modelBase = ko.mapping.fromJS(options.data);
modelBase.CurrentUser.UserName = ko.observable(model.CurrentUser.UserName).extend({ rateLimit: 1000 });
//some function definitions
return modelBase;
},
'CurrentUser': {
create: function (options) {
options.data.MessageToPost = ko.observable("test");
return ko.mapping.fromJS(options.data);
}
}
};
I referred to this post to create the custom mapping, but it seemed not working as the second console.log outputs the same JSON to the first one.
Also, I tried to create nested mapping option based on this thread and another one but it didn't work too.
var mappingOption = {
create: function (options) {
//modelBase, modifing UserName and add the functions
var mappingOption2 = {
'CurrentUser': {
create: function (options) {
return (new(function () {
this.MessageToPost = ko.observable("test");
ko.mapping.fromJS(options.data, mappingOption2, this);
})());
}
}
}
return ko.mapping.fromJS(modelBase, mappingOption2);
}
};
How can I correctly add a new property to the original viewmodel?

From the mapping documentation for ko.toJS (toJS and toJSON work the same way as stated in the document)
Unmapping
If you want to convert your mapped object back to a regular JS object, use:
var unmapped = ko.mapping.toJS(viewModel);
This will create an unmapped object containing only the properties of the mapped object that were part of your original JS object
If you want the json to include properties you've added manually either use ko.toJSON instead of ko.mapping.toJSON to include everything, or use the include option when first creating your object to specify which properties to add.
var mapping = {
'include': ["propertyToInclude", "alsoIncludeThis"]
}
var viewModel = ko.mapping.fromJS(data, mapping);
EDIT: In your specific case your mapping options are conflicting with each other. You've set special instructions for the CurrentUser field but then overridden them in the create function. Here's what I think your mapping options should look like:
var mappingOption = {
'CurrentUser': {
create: function (options) {
var currentUser = ko.mapping.fromJS(options.data, {
'UserName': {
create: function(options){
return ko.observable(options.data);
}
},
'include': ["MessageToPost"]
});
currentUser.MessageToPost = ko.observable("test");
return ko.observable(currentUser).extend({ rateLimit: 1000 });
}
}
};
and here's a fiddle for a working example

Mithril - how to populate drop down list of view from API

I'm trying to populate a drop down box rendered by Mithril's view from methods being called outside of its module (not sure if this terminology is correct, but outside of the property which contains the view, model and controller).
This Chrome extension adds a new field to an existing page and depending on what the user select, the drop down box should refresh to items pertaining to the selected item. I can get up to the stage of getting the new list of items, but i cannot get the drop down list to redraw with the new objects.
The following shows the module which gets inserted inside an existing page:
var ItemsList = {
model: function () {
this.list = function (id) {
var d = m.deferred()
// Calls Chrome extension bg page for retrieval of items.
chromeExt.getItems(pId, function (items) {
// Set default values initially when the controller is called.
if (items.length === 0) {
items = [
{name: 'None', value: 'none'}
]
}
d.resolve(items || [])
})
return d.promise
}
},
controller: function () {
this.model = new ItemsList.model()
this.index = m.prop(0)
this.onchange = function (e) {
console.info('ctrl:onchange', e.target)
}
// Initialise the drop down list array list.
this.dropDownItemsList = m.prop([]);
// This sets the default value of the drop down list to nothing by calling the function in the model,
// until the user selects an item which should populate the drop down list with some values.
this.getItems = function(pId) {
this.model.list(pId).then(function (data) {
this.dropDownItemsList(data)
m.redraw()
}.bind(this))
}
this.getItems(0);
},
view: function (ctrl) {
var SELECT_ID = 'record_select'
return vm.Type() ? m('div', [
m('.form__item', [
m('.label', [
m('label', {
htmlFor: SELECT_ID
}, 'ID')
]),
m('.field', [
m('select#' + SELECT_ID, {
onchange: ctrl.onchange.bind(ctrl)
},
ctrl.dropDownItemsList().map(function (it, i) {
return m('option', {
value: it.value,
checked: ctrl.model.index === i
}, it.name)
})
),
])
]),
]) : null
}
}
And it is mounted using
m.mount("element name here", ItemsList);
The code which checks to see if the item has changed is using a mutation observer, and whenever it detects changes to a certain field, it will call a method to get the new values. I can see that the return value has my new items.
I have tried various different methods on trying to update the drop down list, first by trying to set the "this.list" with the new items list i've got, or trying to create a returnable method on the controller which i can call when the mutation observer fires.
After getting the new items, how can i make the drop down list show the new items which has been retrieved?
I have read guides which shows functions in the controller or model being run - but only if they've been defined to use them already in the view (i.e. have an onclick method on the view which calls the method) but so far i cannot figure out how to update or call methods from outside of the module.
Is there a way to achieve the above or a different method i should approach this?

After some more research into how Mithril works, seems like that it's not possible to call any functions defined within the component.
Due to this, i have moved the model outside of the component (so now it only has the controller and the view defined) and bound the view to use the model outside of the component.
Now calling a function which updates the model (which is now accessible from elsewhere in the code) and redrawing shows the correct values that i need.

If I understand correctly, you need to have two variables to store your lists, one to store the old list and one to store the updated list so you can always map the updated one and go to your old one if you need.
Here is a simple implementation of a drop down list with some methods to update and search. You can update the list on the fly using the methods.
mithDropDown
jsFiddle
var MythDropDown = function(list) {
if (Array.isArray(list))
this.list = list;
else
list = [];
if (!(this instanceof MythDropDown))
return new MythDropDown(list);
var self = this;
this.selected = {
name: list[0],
index: 0
};
this.list = list;
};
MythDropDown.prototype.view = function(ctrl) {
var self = this;
return m('select', {
config: function(selectElement, isinit) {
if (isinit)
return;
self.selectElement = selectElement;
self.update(self.list);
},
onchange: function(e) {
self.selected.name = e.target.value;
self.selected.index = e.target.selectedIndex;
}
},
this.list.map(function(name, i) {
return m('option', name);
}));
};
MythDropDown.prototype.getSelected = function() {
return (this.selected);
};
MythDropDown.prototype.update = function(newList) {
this.list = newList;
this.selectElement.selectedIndex = 0;
this.selected.name = newList[0];
this.selected.index = 0;
};
MythDropDown.prototype.sort = function() {
this.list.sort();
this.update(this.list);
};
MythDropDown.prototype.delete = function() {
this.list.splice(this.selected.index, 1);
this.update(this.list);
};
var list = ['test option 1', 'test option 2'];
var myList = new MythDropDown(list);
var main = {
view: function() {
return m('.content',
m('button', {
onclick: function() {
var L1 = ['Banana', 'Apple', 'Orange', 'Kiwi'];
myList.update(L1);
}
},
'Fruits'),
m('button', {
onclick: function() {
var L1 = ['Yellow', 'Black', 'Orange', 'Brown', 'Red'];
myList.update(L1);
}
},
'Colors'),
m('button', {
onclick: function() {
myList.sort();
}
},
'Sort'),
m('button', {
onclick: function() {
myList.delete();
}
},
'Remove Selected'),
m('', m.component(myList),
m('', 'Selected Item: ' + myList.selected.name, 'Selected Index: ' + myList.selected.index)
)
);
}
};
m.mount(document.body, main);
<script src="https://cdnjs.cloudflare.com/ajax/libs/mithril/0.2.3/mithril.min.js"></script>

Knockout mapping for objects in an array whose property name is dynamic

I have a service that returns data of the following form (I can add fields to this, but I can't change the hierarchical structure):
{
Sections: {
3a: [
{
/* Item definition */
ID: 1,
Text: "Completed Form INNSAMEM002",
...
},
...
],
3b: [
...
],
...
}
}
I would like to use the mapping plugin to call a custom constructor for each of the item definitions, but am having trouble because it is split into sections; so, a mapping would work like this:
var _mapping = {
'3a': {
create: function(o) { return new ItemModel(o.data); }
}
});
However, the section names cannot be known ahead of time.
I can go through the AJAX data, find all the sections, and generate the mapping config from that before I run it, but just wanted to know if there is a better way?
SOLUTION: The answer from CrimsonChris gave me the way to do it; final mapping is this:
var _mapping = {
'Sections': {
create:
function(o)
{
var res = {};
$.each(o.data,
function(sectionkey, section)
{
var secres = [];
$.each(section,
function(itemindex, item)
{
secres.push(new ItemModel(item));
}
);
res[sectionkey] = secres;
}
);
return res;
}
}
};

You can loop over the properties of Sections in the response to get each section. Then map each section's items to an ItemModel.
var _mapping = {
'Sections': {
create: function (options) {
var sections = [];
for (var sectionName in options.data) {
sections.push(new SectionModel(options.data[sectionName], sectionName);
}
return sections;
}
}
}
function SectionModel(items, sectionName) {
this.items = items.map((item) => new ItemModel(item));
this.sectionName = sectionName;
}