Develop Reference

How to create grid with 2 columns of cards [Nativescript and Angular]

Need grid to be something like this:
card1 card2
card3 card4
...
And to be dynamic
Here is my try:
component:
export class MenusComponent implements OnInit {
public menus: any;
constructor() {
this.menus = [
{
image: 'https://www.ducksdailyblog.com/wp-content/uploads/2018/12/Wooden-Post-Country-Fences-Direction.jpg',
title: 'Jelovnik'
},
{
image: 'https://www.ducksdailyblog.com/wp-content/uploads/2018/12/Wooden-Post-Country-Fences-Direction.jpg',
title: 'Pica'
},
{
image: 'https://www.ducksdailyblog.com/wp-content/uploads/2018/12/Wooden-Post-Country-Fences-Direction.jpg',
title: 'Dorucak'
}
]
}
Here is my try:
<GridLayout columns="*,*" rows="*">
<ListView class="list-group" [items]="menus">
<ng-template let-menu="item" let-i="index" let-odd="odd" let-even="even">
<StackLayout [col]="even ? 0 : 1">
<Label [text]="menu.title"></Label>
<Image height="108" width="100%" [src]="menu.image"></Image>
</StackLayout>
</ng-template>
</ListView>
I need to be able to add mre things inside list view so I assume there should be anoter grid as well. What is the right way to do this? Cards need to be equal and to take whole screen.

Using ListViewStaggeredLayout works for me here is the ref: https://docs.nativescript.org/angular/ui/ng-components/ng-radlistview/item-layouts

Horizontal WrapLayout shows elements vertically instead of horizontally

I'm completely new to NativeScript but it looks like a sweet platform. I'm writing a toy app and below is my setup:
//code behind
import {AddExpenseModel} from "./add-expense-view-model";
import {EventData} from "tns-core-modules/data/observable";
import {Page} from "tns-core-modules/ui/page";
let expenseModel = new AddExpenseModel();
export function navigatingTo(args: EventData) {
let page = <Page>args.object;
let textField = page.getViewById("tags");
textField.on("textChange", (ev)=>{expenseModel.onTagsTextFieldChange(ev)});
page.bindingContext = expenseModel;
}
export function submit() {
expenseModel.createNewExpense()
}
//view-model
import {Observable, PropertyChangeData} from "tns-core-modules/data/observable";
import {ObservableArray} from "tns-core-modules/data/observable-array";
let u = require('underscore');
export class AddExpenseModel extends Observable {
...
public parsed_tags;
constructor() {
super();
this.parsed_tags = new ObservableArray([]);
...
}
public onTagsTextFieldChange(ev) {
let that = this;
// empty
u.forEach(u.range(this.parsed_tags.length), function (_) {
that.parsed_tags.pop()
});
let parsed = this.parseTags(ev.value);
u.forEach(parsed, function (el) {
that.parsed_tags.push(el);
});
}
private getParsedTags() {
//unbox
return u.map(this.parsed_tags, (el: string) => el)
}
private parseTags(tag_string) {
let arr = u.map(tag_string.split(','), (tag: string) => tag.trim().toLocaleLowerCase());
arr = u.uniq(arr);
arr = u.filter(arr, u.negate(u.isEmpty))
return arr;
}
}
//view
<Page xmlns="http://schemas.nativescript.org/tns.xsd" navigatingTo="navigatingTo" class="page">
<StackLayout class="p-20">
<Label text="Add new expense"/>
<text-field
id="name" text="{{ name }}"
row="0"/>
<text-field id="amount" stext="{{ amount, amount | numberConverter }}" />
<text-field id="tags" secure="false" text="{{ tags }}"
/>
<WrapLayout orientation="horizontal" height="300" width="300">
<ListView items="{{ parsed_tags }}">
<ListView.itemsLayout>
<Label text="{{ $value }}" width="70" backgroundColor="red"/>
</ListView.itemsLayout>
</ListView>
</WrapLayout>
<button text="Add expense" id="submit-button" tap="submit"/>
</StackLayout>
</Page>
What I want to achieve is that when a user writes in the tags textfield, stylised Labels appear in the WrapLayout. This works, however, the Labels appear always stacked vertically. Here's a screenshot
I tried to move the whole WrapLayout section out of the StackedLayout section, but I get a cannot read property 'on' of undefined, undefined.
Putting Labels inside of WrapLayout not within a ListView (i.e. static) works as expected, which makes me thing I probably misuse either the ListView or the WrapLayout. Any directions will be appreciated :)
Cheers
Update
Following Eddy's advice I used a Repeater. Using the following xml
<Repeater items="{{ parsed_tags }}">
<Repeater.itemsLayout>
<WrapLayout orientation="horizontal" backgroundColor="#d3d3d3"/>
</Repeater.itemsLayout>
<Repeater.itemTemplate>
<Label text="{{ $value }}" backgroundColor="#84ddff" marginRight="5" marginLeft="5"/>
</Repeater.itemTemplate>
</Repeater>
correctly produces this:
I still don't see why using a ListView wouldn't work. I used the debugger from Sidekick and this is what I see.
<ListView items="{{ parsed_tags }}">
<ListView.itemsLayout>
<WrapLayout orientation="horizontal" backgroundColor="#d3d3d3" marginRight="5" marginLeft="5"/>
</ListView.itemsLayout>
<ListView.itemTemplate>
<Label text="{{ $value }}" backgroundColor="#84ddff" marginRight="5" marginLeft="5"/>
</ListView.itemTemplate>
</ListView>

toggle listview content in nativescript with angular

hi i need to toggle individual content in listview when the respective button is clicked in nativescript angular,
i added bellow my code. if anyone know please answer me. thanks in advance
import { Component, OnInit } from "#angular/core";
import { Item } from "./item";
import { ItemService } from "./item.service";
#Component({
selector: "ns-items",
moduleId: module.id,
templateUrl: "./items.component.html",
})
export class ItemsComponent implements OnInit {
items: Item[];
isList = true;
toggle(){
this.isList = !this.isList;
}
constructor(private itemService: ItemService) { }
ngOnInit(): void {
this.items = this.itemService.getItems();
}
}
and here my items.component.html
<ActionBar title="My App" class="action-bar">
</ActionBar>
<StackLayout class="page">
<ListView [items]="items" class="list-group">
<template let-item="item">
<GridLayout columns="auto,auto" width="210" height="210" >
<Label [text]="item.name" col="0"
class="list-group-item" visibility="{{isList ? 'visible' : 'collapse'}}"></Label>
<Button [text]="isList ? 'hide' : 'Show'" col="1" (tap)="toggle()"></Button>
</GridLayout>
</template>
</ListView>
</StackLayout>
here problem is when i click the button all the labels are toggle. so i need to generate the variable dynamically. i m very beginner so anyone can help me?
thank in advance.

Guess you have modified the starter template. So if you want hide label on particular list item, try this.
Add visible property to item.ts
export class Item {
id: number;
name: string;
role: string;
visible: boolean;
}
Set value to visible in your item.service.ts. It will be like below.
{ id: 1, name: "Ter Stegen", role: "Goalkeeper", visible: true },
{ id: 3, name: "Piqué", role: "Defender", visible: true },
Your list template should be
<template let-item="item">
<GridLayout class="list-group-item" columns="*,auto">
<Label col="0" [text]="item.name" [visibility]="item.visible ? 'visible' : 'collapse'"></Label>
<Button class="btn" col="1" [text]="item.visible ? 'Hide' : 'Show'" (tap)="toggle(item)"></Button>
</GridLayout>
</template>
And finally the toggle method will be,
ngOnInit(): void {
this.items = this.itemService.getItems();
}
toggle(item: Item) {
item.visible = !item.visible;
}

Nativescript Angular 2 disable background tap events

I have a login button which when clicked will log the user in by making http calls to the server.
While this is happening I want the activity indicator to show up and disable the button and every other thing on the page and just show the activity indicator over it.
Note that I will place time outs and other measures to make sure that the Activity indicator doesn't end up trapping the user.
Also, I do not want the content in the background to disappear. I just want the activity indicator to overlap it.
Here is my ui code which was taken for this SO answer https://stackoverflow.com/a/39124735/4412482
<GridLayout>
<StackLayout>
//page content goes here
</StackLayout>
</StackLayout>
<StackLayout class="dimmer" visibility="{{showLoading ? 'visible' : 'collapsed'}}"></StackLayout>
<GridLayout rows="*" visibility="{{showLoading ? 'visible' : 'collapsed'}}">
<ActivityIndicator busy="true" width="50" height="50" color="#0c60ee"></ActivityIndicator>
</GridLayout>
</GridLayout>

To disable the events to the components you could use isUserInteractionEnabled property, which will disable the whole interaction to the component and then you could show the ActivityIndicator. I am providing sample code below.
app.component.html
<GridLayout rows="*">
<StackLayout row="0" class="p-20">
<Label text="Tap the button" class="h1 text-center"></Label>
<Button text="TAP" (tap)="onTap()" class="btn btn-primary btn-active" [isUserInteractionEnabled]="buttoninteraction" ></Button>
<Label [text]="message" class="h2 text-center" textWrap="true"></Label>
</StackLayout>
<ActivityIndicator row="0" [busy]="acstate" row="1" class="activity-indicator"></ActivityIndicator>
</GridLayout>
app.component.ts
import { Component } from "#angular/core";
#Component({
selector: "my-app",
templateUrl: "app.component.html",
})
export class AppComponent {
public counter: number = 16;
public buttoninteraction = true;
public acstate = false;
public get message(): string {
if (this.counter > 0) {
return this.counter + " taps left";
} else {
return "Hoorraaay! \nYou are ready to start building!";
}
}
public onTap() {
this.counter--;
this.buttoninteraction=false;
this.acstate=true;
}
}
Hope this helps.

Nativescript Custom Components

I was following this guide to create a a nativescript custom component http://moduscreate.com/custom-components-in-nativescript/ but it's not working for me
I have a folder pages with a folder inside it called main.
main has a couple of files
main.html
<StackLayout
xmlns="http://schemas.nativescript.org/tns.xsd"
xmlns:hello="pages/helllo"
loaded="pageLoaded" >
<hello:hello/>
</StackLayout>
main.component.ts
import { Component, ElementRef, OnInit, ViewChild} from "#angular/core";
import { Page } from "ui/page";
import colorModule = require("color");
var Color = colorModule.Color;
#Component({
selector: "my-app",
templateUrl: "pages/main/main.html",
styleUrls: ["pages/main/main-common.css"]
})
export class MainComponent implements OnInit{
constructor(private page: Page) {
}
ngOnInit() {
this.page.actionBarHidden = true;
}
}
and I also have main-common.css but that's not important to show. I then have another folder inside pages called hello with just one file inside of it
hello.html
<StackLayout width="100%" height="100%" backgroundColorr="red">
<Label class ="h1" text="h1 hello world" color="black"></Label>
<Label class ="h1" text="h1 hello world" color="black"></Label>
<Label class ="h1" text="h1 hello world" color="black"></Label>
<Label class ="h1" text="h1 hello world" color="black"></Label>
<Label class ="h1" text="h1 hello world" color="black"></Label>
<Label class ="h1" text="h1 hello world" color="black"></Label>
<Label class ="h1" text="h1 hello world" color="black"></Label>
<Label class ="h1" text="h1 hello world" color="black"></Label>
<Label class ="h1" text="h1 hello world" color="black"></Label>
<Label class ="h1" text="h1 hello world" color="black"></Label>
<Label class ="h1" text="h1 hello world" color="black"></Label>
</StackLayout>
however the hello component is not showing no matter what i do i am only getting an empty screen. I also tried changing this line xmlns:hello="pages/helllo" in hello.html file to this xmlns:hello="../helllo" but i didn't get anything not even an error. can someone point out what i am doing wrong?

What you are referring as valid in NativeScript Core but won't work in NativeScript + Angular-2.
What you need instead is to create custom component the Angular-2 way.
For demonstration, we can refer to this sample where a custom item component is created. The example is also described in the documentation and it will also show you how to bind data with #Input directive for this component.
Let me guide you through the process.
1.) Create your custom component
using-item-template.component.ts
import { Component, ChangeDetectionStrategy, Input } from "#angular/core";
#Component({
selector: 'item-component',
styleUrls: ["listview/using-item-template/using-item-template.component.css"],
template: `
<StackLayout *ngFor="let element of data.list" class="model">
<Label [text]="element.model" class="name"></Label>
<Label [text]="element.speed +'mph'" class="speed"></Label>
</StackLayout>
`
})
export class ItemComponent {
#Input() data: any; // this way we "pass data" to our item-component
}
#Component({
selector: 'using-item-template',
styleUrls: ["listview/using-item-template/using-item-template.component.css"],
templateUrl: "listview/using-item-template/using-item-template.component.html",
changeDetection: ChangeDetectionStrategy.OnPush
})
export class UsingItemTemplateComponent {
public manufacturers: Array<any>;
constructor() {
var bugatti = [{ "model": "Bugatti Chiron", "speed": "261" }, { "model": "Bugatti Veyron Super Sport", "speed": "268" }];
var mclaren = [{ "model": "McLaren P1", "speed": "211" }, { "model": "McLaren F1", "speed": "242" }];
var jaguar = [{ "model": "Jaguar XJ220", "speed": 217 }];
this.manufacturers = [{ "list": bugatti }, { "list": mclaren }, { "list": jaguar }];
}
}
using-item-template.component.html
<StackLayout exampleTitle toggleNavButton>
<GridLayout rows="50, *" class="example-container">
<Label text="Top Cars" row="0" class="title" textWrap="true" horizontalAlignment="center"></Label>
<ListView [items]="manufacturers" row="1">
<template let-item="item">
<item-component [data]="item" ></item-component>
</template>
</ListView>
</GridLayout>
</StackLayout>
The last but also crucial part is not to forget to declare your ItemComponent in the NgModule!
main.ts
import { ItemComponent } from "./listview/using-item-template/using-item-template.component";
#NgModule({
declarations: [
ItemComponent, // declare the item component
// the other components in your app
],
bootstrap: [AppComponent],
imports: [
.....
],
})
class AppComponentModule { }