I am trying to make a table component, which I have completed, I want to add a feature to the component where I can customize individual cells in the component. I am not exactly sure how to do this.
So I have seen this implemented like the following:
model is the data related to the table (headers, rows, pagination, etc.)
matches is the column name to match (in the headers id what is match, in rows it is the property key).
let-content is the data associated with the cell for that row.
<ui-table [model]="tableModel">
<ng-template matches="columnA" let-content="content">
{{content | commaSeparate}}
</ng-template>
</ui-table>
public tableModel = {
headers: [
{ title: 'Column A', id: 'columnA' },
{ title: 'Column B', id: 'columnB' }
],
rows: [
{ columnA: ['A', 'B'], columnB: 'Column B' },
{ columnA: ['C', 'D'], columnB: 'Column B2' }
]
}
In my ui-table component I have the following table body:
<tbody #tBody class="uitk-c-table__body">
<tr *ngFor="let row of rowItems" class="uitk-c-table__row">
<!-- If "matches === model.headers[x].id" show the custom cell -->
<td *ngFor="let cell of model.headers; index as c">{{row[model.headers[c].id] || ''}}</td>
</tr>
</tbody>
What I am not sure of, is how do I show the custom cell ng-template if matches === model.headers[x].id?
Inside your ui-table component, let's define a input property:
#Input() passedTemplate: TemplateRef<any>;
#Input() displayContent: any // to display variable inside ng-template
And define a input property in order to pass your ng-template to
Like this:
<ui-table [model]="tableModel" [passedTemplate]='template' [displayContent]='content'>
</ui-table>
<ng-template #template matches="columnA" let-content="content">
{{content | commaSeparate}}
</ng-template>
Then try to use ng-container in your ui-table html file:
<ng-container *ngIf="matches === model.headers[x].id"
[ngTemplateOutlet]="passedTemplate"
[ngTemplateOutletContext]="{content: displayContent}">
</ng-container>
Hope this help...
I was able to figure it out. First I create a directive which contains a match property which is the column I want to match on, and a tableCell property which is the template within the directive.
#Directive({ selector: 'ui-table-cell' })
export class TableCellDirective {
#Input() public match: string = '';
#ContentChild('tableCell', { static: false }) public tableCell!: any;
}
Next when the table loads I load all of the templates into an object where the key is the cell id and the value is the template.
export class TableComponent implements AfterContentInit {
#ContentChildren(TableCellDirective)
public cellDirectives!: QueryList<TableCellDirective>;
public columnMeta: { [key: string]: object; } = {};
public ngAfterContentInit() {
this.cellDirectives.toArray().forEach(colData => this.assignColumnMetaInfo(colData));
}
private assignColumnMetaInfo(colData: TableCellDirective) {
const columnMetaInfo: { [key: string]: object; } = {};
columnMetaInfo['tableCell'] = colData.tableCell;
this.columnMeta[colData.match] = columnMetaInfo;
}
}
In the HTML, I then check if the current cell has a template saved if so, I display the template. If not I display the original data.
<tr *ngFor="let row of rowItems" class="uitk-c-table__row">
<td *ngFor="let cell of model.headers">
<ng-container *ngIf="columnMeta[cell.id] && columnMeta[cell.id].tableCell" [ngTemplateOutlet]="columnMeta[cell.id].tableCell" [ngTemplateOutletContext]="{content: row[cell.id]}"></ng-container>
<ng-container *ngIf="!columnMeta[cell.id]">{{row[cell.id] || ''}}</ng-container>
</td>
</tr>
Finally, to use it I just do the following:
<ui-table *ngIf="tableDataModel.rows?.length>0" [model]="tableDataModel" (onRequestEdit)="onOpenEdit($event)">
<ui-table-cell match="permissions">
<ng-template #tableCell let-content="content">
{{content|arrayToList}}
</ng-template>
</ui-table-cell>
</ui-table>
I have ag-grid when a lot of columns have specific templates. But some of data that I put into table are nothing more than just text until now.. I want to put something more for default case:
<ng-template #defaultRecord let-record>
ADDITIONAL THINGS HERE
<!-- CHOOSEN FIELD HERE -->
</ng-template>
So I have method for autogenerating columns:
private generateColumn(headerNameKey: string, colId: string, ngTemplate: TemplateRef<any>, filter = true, sortable = true, field?: string) {
const headerName = headerNameKey ? this.translateService.instant(headerNameKey) : '';
return {
headerName,
field,
sortable,
filter,
colId,
cellRendererFramework: CellRendererComponent,
cellRendererParams: {
ngTemplate
}
};
}
And I don't know how to use unspecified field in template. For example I get from api data when field is called "XYZ", how to make display it in my default template?
In this case:
<ng-template #defaultRecord let-record>
ADDITIONAL THINGS HERE
<span> Value of XYZ param</span>
</ng-template>
Can someone help me? Thanks!
EDIT 1:
Custom CellRenderer Component:
export class CellRendererComponent implements ICellRendererAngularComp {
template: TemplateRef<any>;
templateContext: { $implicit: any, params: ICellRendererParams };
agInit(params: ICellRendererParams) {
this.template = params['ngTemplate'];
this.refresh(params);
}
refresh(params: ICellRendererParams): boolean {
this.templateContext = {
$implicit: params.data,
params
};
return true;
}
}
And how params in agInit method looks:
And as You can see in the picture, in the template I want to display value of Fields.Date param that is defined field. How I suppose to use it in the template above?
if I understand correctly what you want to do.
Then here is one way.
You add context parameter to the template context.
<ng-template #defaultRecord let-record let-value="value">
ADDITIONAL THINGS HERE
<span> {{value}} </span>
</ng-template>
And you calculate this value in renderer component.
refresh(params: ICellRendererParams): boolean {
const valuePath = params.colDef.field;
const value = _.get(params.data, valuePath); // using lodash
this.templateContext = {
$implicit: params.data,
params,
value
};
return true;
}
I am using lodash function, but you can use other library or write simple method to get value from the object using its path.
I have a page with three components:
1. Products list component which gets some products as input and display them.
2. Filters component which displays some filters list i.e. (size, colour,...) and also display the added filters.
3. Main component which is the root component
Let say a user adds 1 filter which fires a http request to get new filtered products and while the request is pending he removes the added filter which fires another http request to fetch all the products
How to cancel the first request so we don't display the filtered products?
Here is my code:
class FiltersService {
private _filters: any[];
get filters() {
return this._filters;
}
addFilter(filter) {
this._filters.push(filter);
}
removeFilter(filter) {
// Remove filter logic ...
}
}
class DataService_ {
constructor(private http: HttpClient) {
}
getProducts(filters) {
return this.http.post<any[]>('api/get-products', filters)
}
}
#Component({
selector: 'app-main',
template: `
<div>
<app-filters [filtersChanged]="onFiltersChange()"></app-filters>
<app-products-list [products]="products"> </app-products-list>
</div>
`
})
class MainComponent {
products: any[];
constructor(private dataService: DataService_, private filtersService: FiltersService) {
}
ngOnInit() {
this.setProducts()
}
setProducts() {
let filters = this.filtersService.filters;
this.dataService.getProducts(filters)
.subscribe(products => this.products = products)
}
onFiltersChange() {
this.setProducts();
}
}
#Component({
selector: 'app-filters',
template: `
<div>
Filters :
<ul>
<li *ngFor="let filter of filters" (click)="addFilter(filter)"> {{ filter.name }}</li>
</ul>
<hr>
Added Filters:
<ul>
<li *ngFor="let filter of filtersService.filters"> {{ filter.name }} <button (click)="removeFilter(filter)"> Remove</button></li>
</ul>
</div>
`
})
class FiltersComponent {
filters = [{ name: 'L', tag: 'size' }, { name: 'M', tag: 'size' }, { name: 'White', tag: 'colour' }, { name: 'Black', tag: 'colour' }]
#Output() filtersChanged = new EventEmitter()
constructor(public filtersService: FiltersService) {
}
addFilter(filter) {
const isAdded = this.filtersService.filters.find(x => x.name === filter.name);
if (isAdded) return;
this.filtersService.addFilter(filter);
this.filtersChanged.emit()
}
removeFilter(filter) {
this.filtersService.remove(filter);
this.filtersChanged.emit()
}
}
#Component({
selector: 'app-products-list',
template: `
<div>
<h1>Products</h1>
<ul *ngIf="products.length">
<li *ngFor="let product of products">
{{product.name }}
</li>
</ul>
</div>
`
})
class ProductsListComponent {
#Input() products
constructor() {
}
}
Long story short:
Easiest way to handle such situations is by using the switchMap operator. What this does is cancel the internal subscription as soon as a new event comes along.
One implementation would be:
class MainComponent {
products: any[];
private _filters$ = new Subject();
constructor(private dataService: DataService_, private filtersService: FiltersService) {
}
ngOnInit() {
this.setProducts()
}
setProducts() {
this._filters$
.switchMap((filters)=> this.dataService.getProducts(filters)) // or .let(switchMap...) if you are using rxjs >5.5
.subscribe(products => this.products = products);
}
onFiltersChange() {
this._filters$.next(this.filtersService.filters);
}
}
Long story:
What happens here is:
When you change filter the onFilterChange is triggered. You then emit the latest filters (inside this.filtersService.filters) through the _filters$ Subject (a subject is almost identical to an EventEmitter).
Back in time during component initialization the ngOnInit method has called setProducts, which has subscribed to the _filters$ subject for future events (none has happened at this point). When an event arrives on _filters$ then we trigger the getProducts method of dataservice, passing it the filters that where contained in the event. We will be waiting on this line until the http call has completed. As soon as it completes the result of the http call will be assigned to the products of the component.
If while we are waiting for the http response to get back, onFiltersChange is fired again, then a new event will arive at the switchMap and it will cancel the previous http request so that it can handle the new event.
This is a very powerful approach as changing a single operator, you can easily change the behavior of your app. For instance, changing switchMap to concatMap will make the request wait for the previous one to complete (will happen serially). Changing it to flatMap will have the same behaviour as the original code you posted (http requests will happen as soon as filters change, without affecting previous ones, order of responses will not predictable) and so on.
Note : to cancel the request just use unsubscribe.
For exmple
const course$ = this.service$.getCourses(`/api/courses`).subscribe(courses => { console.log(courses) }
setTimeout(() => course$.unsubscribe(),1000) // cancel the request
I have a simple demo app which I'm simulating manually insert / fetch data from DB and injecting new components - according to the num entered.
Plunker
So if I click the "manual " button twice :
And if I set "3" in the text and click "fetch from db" - I get the expected delay(simulate db) and then :
This all works as expected.
The "parent" component is :
//src/MainPage.ts
#Component({
selector: 'my-app',
template: `
<button (click)="putInMyHtml()">Insert component manually</button>
<p> # Items to fetch : <input type="text" style='width:40px' [(ngModel)]="dbNumItems" name="dbNumItems"/> <input type='button' value='fetch from db' (click)='fetchItems($event)'/></p>
<div #myDiv>
<template #target></template>
</div>
`
})
export class MainPage {
#ViewChild('target', { read: ViewContainerRef }) target: ViewContainerRef;
dbNumItems: string;
constructor(private cfr: ComponentFactoryResolver) {}
fetchItems(){
var p= new Promise((resolve, reject) => { //simulate db
setTimeout(()=>resolve(this.dbNumItems),2000)
});
p.then(v=>{
for (let i =0;i<v;i++)
{
this.putInMyHtml() ;// inject "v" times
}
})
}
putInMyHtml() {
// this.target.clear();
let compFactory = this.cfr.resolveComponentFactory(TestPage);
this.target.createComponent(compFactory);
}
}
This is the Injected component :
//src/TestPage.ts
#Component({
selector: 'test-component',
template: '<b>Content : Name={{user.Name}} Age={{user.Age}}</b><br/>',
})
export class TestPage {
#Input
User:Person;
}
So where is the problem ?
As you can see , in the injected component I have :
#Input
User:Person;
which means that I want the parent component to pass a Person object to each injection.
In other words :
Question
Looking at the "after db stage" , How can I pass a customized person to each injection ?
p.then(v=>{
for (let i =0;i<v;i++)
{
let p = new Person();
p.Name = "name"+i;
p.Age = i;
this.putInMyHtml() ; //how to I pass `p` ???
}
})
}
Expected output :
NB
I don't want to use ngFor because I don't need to hold an Array at the back end. this is an app which injects new articles periodically.and I will be glad to know if there's a better way of doing it.
You can do it with the instance property of component ref like this:
putInMyHtml(p) {
// this.target.clear();
let compFactory = this.cfr.resolveComponentFactory(TestPage);
let ref = this.target.createComponent(compFactory);
ref.instance.user = p;
}
-Fixed the #Input() binding, syntax was wrong.
-Added a safe-navigation operator (?) for the template to do the null checks for the async input.
Fixed plunker: https://plnkr.co/edit/WgWFZQLxt9RFoZLR46HH?p=preview
use *ngFor and iterate through an array of Person, that way you can use the #Input. You probably want something like
<ul>
<li *ngFor="let person of people">
<test-component [User]=person></test-component>
</li>
</ul>
add people: Person[] to your main component and when you fetch items
p.then(v=>{
for (let i =0;i<v;i++)
{
let p = new Person();
p.Name = "name"+i;
p.Age = i;
people.push(p)
}
})
This question already has answers here:
access key and value of object using *ngFor
(21 answers)
Closed 1 year ago.
I am trying to do some things in Angular 2 Alpha 28, and am having an issue with dictionaries and ngFor.
I have an interface in TypeScript looking like this:
interface Dictionary {
[index: string]: string
}
In JavaScript this will translate to an object that with data might look like this:
myDict={'key1':'value1','key2':'value2'}
I want to iterate over this and tried this:
<div *ngFor="(#key, #value) of myDict">{{key}}:{{value}}</div>
But to no avail, none of the below worked either:
<div *ngFor="#value of myDict">{{value}}</div>
<div *ngFor="#value of myDict #key=index">{{key}}:{{value}}</div>
In all cases I get errors like Unexpected token or Cannot find 'iterableDiff' pipe supporting object
What am I missing here? Is this not possible anymore? (The first syntax works in Angular 1.x) or is the syntax different for iterating over an object?
Angular 6.1.0+ Answer
Use the built-in keyvalue-pipe like this:
<div *ngFor="let item of myObject | keyvalue">
Key: <b>{{item.key}}</b> and Value: <b>{{item.value}}</b>
</div>
or like this:
<div *ngFor="let item of myObject | keyvalue:mySortingFunction">
Key: <b>{{item.key}}</b> and Value: <b>{{item.value}}</b>
</div>
where mySortingFunction is in your .ts file, for example:
mySortingFunction = (a, b) => {
return a.key > b.key ? -1 : 1;
}
Stackblitz: https://stackblitz.com/edit/angular-iterate-key-value
You won't need to register this in any module, since Angular pipes work out of the box in any template.
It also works for Javascript-Maps.
It appears they do not want to support the syntax from ng1.
According to Miško Hevery (reference):
Maps have no orders in keys and hence they iteration is unpredictable.
This was supported in ng1, but we think it was a mistake and will not
be supported in NG2
The plan is to have a mapToIterable pipe
<div *ngFor"var item of map | mapToIterable">
So in order to iterate over your object you will need to use a "pipe".
Currently there is no pipe implemented that does that.
As a workaround, here is a small example that iterates over the keys:
Component:
import {Component} from 'angular2/core';
#Component({
selector: 'component',
templateUrl: `
<ul>
<li *ngFor="#key of keys();">{{key}}:{{myDict[key]}}</li>
</ul>
`
})
export class Home {
myDict : Dictionary;
constructor() {
this.myDict = {'key1':'value1','key2':'value2'};
}
keys() : Array<string> {
return Object.keys(this.myDict);
}
}
interface Dictionary {
[ index: string ]: string
}
try to use this pipe
import { Pipe, PipeTransform } from '#angular/core';
#Pipe({ name: 'values', pure: false })
export class ValuesPipe implements PipeTransform {
transform(value: any, args: any[] = null): any {
return Object.keys(value).map(key => value[key]);
}
}
<div *ngFor="#value of object | values"> </div>
Updated : Angular is now providing the pipe for looping through a json Object via keyvalue :
<div *ngFor="let item of myDict | keyvalue">
{{item.key}}:{{item.value}}
</div>
WORKING DEMO , and for more detail Read
Previously (For Older Version) : Till now the best / shortest answer I found is ( Without any Pipe Filter or Custom function from Component Side )
Component side :
objectKeys = Object.keys;
Template side :
<div *ngFor='let key of objectKeys(jsonObj)'>
Key: {{key}}
<div *ngFor='let obj of jsonObj[key]'>
{{ obj.title }}
{{ obj.desc }}
</div>
</div>
WORKING DEMO
In addition to #obscur's answer, here is an example of how you can access both the key and value from the #View.
Pipe:
#Pipe({
name: 'keyValueFilter'
})
export class keyValueFilterPipe {
transform(value: any, args: any[] = null): any {
return Object.keys(value).map(function(key) {
let pair = {};
let k = 'key';
let v = 'value'
pair[k] = key;
pair[v] = value[key];
return pair;
});
}
}
View:
<li *ngFor="let u of myObject |
keyValueFilter">First Name: {{u.key}} <br> Last Name: {{u.value}}</li>
So if the object were to look like:
myObject = {
Daario: Naharis,
Victarion: Greyjoy,
Quentyn: Ball
}
The generated outcome would be:
First name: Daario
Last Name: Naharis
First name: Victarion
Last Name: Greyjoy
First name: Quentyn
Last Name: Ball
Adding to SimonHawesome's excellent answer. I've made an succinct version which utilizes some of the new typescript features. I realize that SimonHawesome's version is intentionally verbose as to explain the underlying details. I've also added an early-out check so that the pipe works for falsy values. E.g., if the map is null.
Note that using a iterator transform (as done here) can be more efficient since we do not need to allocate memory for a temporary array (as done in some of the other answers).
import {Pipe, PipeTransform} from '#angular/core';
#Pipe({
name: 'mapToIterable'
})
export class MapToIterable implements PipeTransform {
transform(map: { [key: string]: any }, ...parameters: any[]) {
if (!map)
return undefined;
return Object.keys(map)
.map((key) => ({ 'key': key, 'value': map[key] }));
}
}
Here's a variation on some of the above answers that supports multiple transforms (keyval, key, value):
import { Pipe, PipeTransform } from '#angular/core';
type Args = 'keyval'|'key'|'value';
#Pipe({
name: 'mapToIterable',
pure: false
})
export class MapToIterablePipe implements PipeTransform {
transform(obj: {}, arg: Args = 'keyval') {
return arg === 'keyval' ?
Object.keys(obj).map(key => ({key: key, value: obj[key]})) :
arg === 'key' ?
Object.keys(obj) :
arg === 'value' ?
Object.keys(obj).map(key => obj[key]) :
null;
}
}
Usage
map = {
'a': 'aee',
'b': 'bee',
'c': 'see'
}
<div *ngFor="let o of map | mapToIterable">{{o.key}}: {{o.value}}</div>
<div>a: aee</div>
<div>b: bee</div>
<div>c: see</div>
<div *ngFor="let o of map | mapToIterable:'keyval'">{{o.key}}: {{o.value}}</div>
<div>a: aee</div>
<div>b: bee</div>
<div>c: see</div>
<div *ngFor="let k of map | mapToIterable:'key'">{{k}}</div>
<div>a</div>
<div>b</div>
<div>c</div>
<div *ngFor="let v of map | mapToIterable:'value'">{{v}}</div>
<div>aee</div>
<div>bee</div>
<div>see</div>
I had a similar issue, built something for objects and Maps.
import { Pipe } from 'angular2/core.js';
/**
* Map to Iteratble Pipe
*
* It accepts Objects and [Maps](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map)
*
* Example:
*
* <div *ngFor="#keyValuePair of someObject | mapToIterable">
* key {{keyValuePair.key}} and value {{keyValuePair.value}}
* </div>
*
*/
#Pipe({ name: 'mapToIterable' })
export class MapToIterable {
transform(value) {
let result = [];
if(value.entries) {
for (var [key, value] of value.entries()) {
result.push({ key, value });
}
} else {
for(let key in value) {
result.push({ key, value: value[key] });
}
}
return result;
}
}
Angular 2.x && Angular 4.x do not support this out of the box
You can use this two pipes to iterate either by key or by value.
Keys pipe:
import {Pipe, PipeTransform} from '#angular/core'
#Pipe({
name: 'keys',
pure: false
})
export class KeysPipe implements PipeTransform {
transform(value: any, args: any[] = null): any {
return Object.keys(value)
}
}
Values pipe:
import {Pipe, PipeTransform} from '#angular/core'
#Pipe({
name: 'values',
pure: false
})
export class ValuesPipe implements PipeTransform {
transform(value: any, args: any[] = null): any {
return Object.keys(value).map(key => value[key])
}
}
How to use:
let data = {key1: 'value1', key2: 'value2'}
<div *ngFor="let key of data | keys"></div>
<div *ngFor="let value of data | values"></div>
//Get solution for ng-repeat
//Add variable and assign with Object.key
export class TestComponent implements OnInit{
objectKeys = Object.keys;
obj: object = {
"test": "value"
"test1": "value1"
}
}
//HTML
<div *ngFor="let key of objectKeys(obj)">
<div>
<div class="content">{{key}}</div>
<div class="content">{{obj[key]}}</div>
</div>
If someone is wondering how to work with multidimensional object, here is the solution.
lets assume we have following object in service
getChallenges() {
var objects = {};
objects['0'] = {
title: 'Angular2',
description : "Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur."
};
objects['1'] = {
title: 'AngularJS',
description : "Lorem Ipsum is simply dummy text of the printing and typesetting industry."
};
objects['2'] = {
title: 'Bootstrap',
description : "Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.",
};
return objects;
}
in component add following function
challenges;
constructor(testService : TestService){
this.challenges = testService.getChallenges();
}
keys() : Array<string> {
return Object.keys(this.challenges);
}
finally in view do following
<div *ngFor="#key of keys();">
<h4 class="heading">{{challenges[key].title}}</h4>
<p class="description">{{challenges[key].description}}</p>
</div>
I have been tearing my hair out with trying to parse and use data returned form a JSON query/ api call. Im not sure exactly where i was going wrong, i feel like i have been circling the answer for days, chasing various error codes like:
"Cannot find 'iterableDiff' pipe supporting object"
"Generic TYpe Array requires one argument(s)"
JSON parsing Errors, and im sure others
Im assuming i just had the wrong combination of fixes.
So here's a bit of a summary of gotchas and things to look for.
Firstly check the result of your api calls, your results may be in the form of an object, an array, or an array of objects.
i wont go into it too much, suffice to say the OP's original Error of not being iterable is generally caused by you trying to iterate an object, not an Array.
Heres some of my debugging results showing variables of both arrays and objects
So as we generally would like to iterate over our JSON result we need to ensure it is in the form of an Array. I tried numerous examples, and perhaps knowing what i know now some of those would in fact work, but the approach i went with was indeed to implement a pipe and the code i used was that the posted by t.888
transform(obj: {[key: string]: any}, arg: string) {
if (!obj)
return undefined;
return arg === 'keyval' ?
Object.keys(obj).map((key) => ({ 'key': key, 'value': obj[key] })) :
arg === 'key' ?
Object.keys(obj) :
arg === 'value' ?
Object.keys(obj).map(key => obj[key]) :
null;
Honestly i think one of the things that was getting me was the lack of error handling, by adding the 'return undefined' call i believe we are now allowing for non expected data to be sent to the pipe, which obviously was occurring in my case.
if you don't want to deal with argument to the pipe (and look i don't think it's necessary in most cases) you can just return the following
if (!obj)
return undefined;
return Object.keys(obj);
Some Notes on creating your pipe and page or component that uses that pipe
is i was receiving errors about ‘name_of_my_pipe’ not being found
Use the ‘ionic generate pipe’ command from the CLI to ensure the pipe modules.ts are created and referenced correctly. ensure you add the following to the mypage.module.ts page.
import { PipesModule } from ‘…/…/pipes/pipes.module’;
(not sure if this changes if you also have your own custom_module, you may also need to add it to the custommodule.module.ts)
if you used the 'ionic generate page' command to make your page, but decide to use that page as your main page, remember to remove the page reference from app.module.ts (here's another answer i posted dealing with that https://forum.ionicframework.com/t/solved-pipe-not-found-in-custom-component/95179/13?u=dreaser
In my searching for answers there where a number of ways to display the data in the html file, and i don't understand enough to explain the differences. You may find it better to use one over another in certain scenarios.
<ion-item *ngFor="let myPost of posts">
<img src="https://somwhereOnTheInternet/{{myPost.ImageUrl}}"/>
<img src="https://somwhereOnTheInternet/{{posts[myPost].ImageUrl}}"/>
<img [src]="'https://somwhereOnTheInternet/' + myPost.ImageUrl" />
</ion-item>
However what worked that allowed me to display both the value and the key was the following:
<ion-list>
<ion-item *ngFor="let myPost of posts | name_of_pip:'optional_Str_Varible'">
<h2>Key Value = {{posts[myPost]}}
<h2>Key Name = {{myPost}} </h2>
</ion-item>
</ion-list>
to make the API call it looks like you need to import HttpModule into app.module.ts
import { HttpModule } from '#angular/http';
.
.
imports: [
BrowserModule,
HttpModule,
and you need Http in the page you make the call from
import {Http} from '#angular/http';
When making the API call you seem to be able to get to the children data (the objects or arrays within the array) 2 different ways, either seem to work
either during the call
this.http.get('https://SomeWebsiteWithAPI').map(res => res.json().anyChildren.OrSubChildren).subscribe(
myData => {
or when you assign the data to your local variable
posts: Array<String>;
this.posts = myData['anyChildren'];
(not sure if that variable needs to be an Array String, but thats what i have it at now. It may work as a more generic variable)
And final note, it was not necessary to use the inbuilt JSON library
however you may find these 2 calls handy for converting from an object to a string and vica versa
var stringifiedData = JSON.stringify(this.movies);
console.log("**mResults in Stringify");
console.log(stringifiedData);
var mResults = JSON.parse(<string>stringifiedData);
console.log("**mResults in a JSON");
console.log(mResults);
I hope this compilation of info helps someone out.
The dictionary is an object, not an array. I believe ng-repeat requires an array in Angular 2.
The simplest solution would be to create a pipe/filter that converts the object to an array on the fly. That said, you probably want to use an array as #basarat says.
If you have es6-shim or your tsconfig.json target es6, you could use ES6 Map to make it.
var myDict = new Map();
myDict.set('key1','value1');
myDict.set('key2','value2');
<div *ngFor="let keyVal of myDict.entries()">
key:{{keyVal[0]}}, val:{{keyVal[1]}}
</div>
In JavaScript this will translate to an object that with data might look like this
Interfaces in TypeScript are a dev time construct (purely for tooling ... 0 runtime impact). You should write the same TypeScript as your JavaScript.
Define the MapValuesPipe and implement PipeTransform:
import {Pipe, PipeTransform} from '#angular/core';
#Pipe({name: 'mapValuesPipe'})
export class MapValuesPipe implements PipeTransform {
transform(value: any, args?: any[]): Object[] {
let mArray:
value.forEach((key, val) => {
mArray.push({
mKey: key,
mValue: val
});
});
return mArray;
}
}
Add your pipe in your pipes module. This is important if you need to use the same pipe in more than one components:
#NgModule({
imports: [
CommonModule
],
exports: [
...
MapValuesPipe
],
declarations: [..., MapValuesPipe, ...]
})
export class PipesAggrModule {}
Then simply use the pipe in your html with *ngFor:
<tr *ngFor="let attribute of mMap | mapValuesPipe">
Remember, you will need to declare your PipesModule in the component where you want to use the pipe:
#NgModule({
imports: [
CommonModule,
PipesAggrModule
],
...
}
export class MyModule {}
So I was going to implement my own helper function, objLength(obj), which returns just Object(obj).keys.length. But then when I was adding it to my template *ngIf function, my IDE suggested objectKeys(). I tried it, and it worked. Following it to its declaration, it appears to be offered by lib.es5.d.ts, so there you go!
Here's how I implemented it (I have a custom object that uses server-side generated keys as an index for files I've uploaded):
<div *ngIf="fileList !== undefined && objectKeys(fileList).length > 0">
<h6>Attached Files</h6>
<table cellpadding="0" cellspacing="0">
<tr *ngFor="let file of fileList | keyvalue">
<td>{{file.value['fileName']}}</td>
<td class="actions">
<a title="Delete File" (click)="deleteAFile(file.key);">
</a>
</td>
</tr>
</table>
</div>
There's another way to loop over objects, using structural directives:
I prefer this approach because it "feels" most like the normal ngFor loop. :-)
(In this case for example I added Angular's context variables let i = index | even | odd | first | last | count) that are accessible inside my loop).
#Directive({
selector: '[ngForObj]'
})
export class NgForObjDirective implements OnChanges {
#Input() ngForObjOf: { [key: string]: any };
constructor(private templateRef: TemplateRef<any>, private viewContainerRef: ViewContainerRef) { }
ngOnChanges(changes: SimpleChanges): void {
if (changes.ngForObjOf && changes.ngForObjOf.currentValue) {
// remove all views
this.viewContainerRef.clear();
// create a new view for each property
const propertyNames = Object.keys(changes.ngForObjOf.currentValue);
const count = propertyNames.length;
propertyNames.forEach((key: string, index: number) => {
const even = ((index % 2) === 0);
const odd = !even;
const first = (index === 0);
const last = index === (count - 1);
this.viewContainerRef.createEmbeddedView(this.templateRef, {
$implicit: changes.ngForObjOf.currentValue[key],
index,
even,
odd,
count,
first,
last
});
});
}
}
}
Usage in your template:
<ng-container *ngForObj="let item of myObject; let i = index"> ... </ng-container>
And if you want to loop using an integer value, you can use this directive:
#Directive({
selector: '[ngForInt]'
})
export class NgForToDirective implements OnChanges {
#Input() ngForIntTo: number;
constructor(private templateRef: TemplateRef<any>, private viewContainerRef: ViewContainerRef) {
}
ngOnChanges(changes: SimpleChanges): void {
if (changes.ngForIntTo && changes.ngForIntTo.currentValue) {
// remove all views
this.viewContainerRef.clear();
let currentValue = parseInt(changes.ngForIntTo.currentValue);
for (let index = 0; index < currentValue; index++) {
this.viewContainerRef.createEmbeddedView(this.templateRef, {
$implicit: index,
index
});
}
}
}
}
Usage in your template (example: loop from 0 to 14 (= 15 iterations):
<ng-container *ngForInt="let x to 15"> ... </ng-container>