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https://github.com/udos86/ng-dynamic-forms
Rapid form development library for Angular
https://github.com/udos86/ng-dynamic-forms
angular bootstrap dynamic-forms forms foundation ionic kendo-ui material ng-bootstrap ngx-bootstrap primeng
Last synced: about 1 month ago
JSON representation
Rapid form development library for Angular
- Host: GitHub
- URL: https://github.com/udos86/ng-dynamic-forms
- Owner: udos86
- License: isc
- Created: 2016-06-01T20:26:33.000Z (about 8 years ago)
- Default Branch: master
- Last Pushed: 2024-02-06T11:28:40.000Z (4 months ago)
- Last Synced: 2024-05-03T06:13:32.865Z (about 1 month ago)
- Topics: angular, bootstrap, dynamic-forms, forms, foundation, ionic, kendo-ui, material, ng-bootstrap, ngx-bootstrap, primeng
- Language: TypeScript
- Homepage:
- Size: 8.68 MB
- Stars: 1,305
- Watchers: 69
- Forks: 369
- Open Issues: 128
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
Lists
- awesome-ionic2-components - Dynamic Forms
- awesome - ng-dynamic-forms
- awesome-angular - ng-dynamic-forms - Rapid form development library for Angular. (Table of contents / Third Party Components)
README
# NG Dynamic Forms
[](https://badge.fury.io/js/%40ng-dynamic-forms%2Fcore)
[](https://github.com/udos86/ng-dynamic-forms/actions)
[](https://codecov.io/gh/udos86/ng-dynamic-forms)
[](https://deepscan.io/dashboard/#view=project&pid=562&bid=912)
[](https://npmjs.org/package/@ng-dynamic-forms/core)
***
NG Dynamic Forms is a **rapid form development library** based on the official Angular
[**dynamic forms guide**](https://angular.io/docs/ts/latest/cookbook/dynamic-form.html).
It **fully automates form UI creation** by introducing a set of maintainable **form control models** and **dynamic form control components**
**Out of the box support** is provided for all popular UI libraries including **[Material](https://material.angular.io/)**, **[ngx-bootstrap](https://valor-software.com/ngx-bootstrap/#/)**, **[NG Bootstrap](https://ng-bootstrap.github.io/#/home)**, **[Foundation](http://foundation.zurb.com/)**, **[Ionic](http://ionicframework.com/)** and **[PrimeNG](http://www.primefaces.org/primeng/#/)**.
Explore the [**live sample**](http://ng2-dynamic-forms.udos86.de/sample/index.html) and the [**API documentation**](http://ng2-dynamic-forms.udos86.de/docs/index.html)!
## Table of Contents
- [Getting Started](#getting-started)
- [Running the Sample](#running-the-sample)
- [Basic Usage](#basic-usage)
- [UI Modules](#ui-modules)
- [Form Groups](#form-groups)
- [Form Arrays](#form-arrays)
- [Form Layouts](#form-layouts)
- [Form Control Configuration](#form-control-configuration)
- [Form Control Events](#form-control-events)
- [Updating Form Controls](#updating-form-controls)
- [Custom Templates](#custom-templates)
- [Custom Validators](#custom-validators)
- [Custom Form Controls](#custom-form-controls)
- [Validation Messaging](#validation-messaging)
- [Related Form Controls](#related-form-controls)
- [JSON Export & Import](#json-export--import)
- [JSON Form Models](#json-form-models)
- [Text Masks](#text-masks)
- [Autocompletion](#autocompletion)
- [FAQ](#faq)
- [Appendix](#appendix)
## Getting Started
**1. Install the core package**:
```
npm i @ng-dynamic-forms/core -S
```
**2. Install a [UI package](#ui-modules) and its peer dependencies**:
```
npm i @ng-dynamic-forms/ui-material -S
```
## Running the Sample
**1. Clone the Git repository**:
```
git clone https://github.com/udos86/ng-dynamic-forms.git
cd ng-dynamic-forms
```
**2. Install the dependencies**:
```
npm i
```
**3. Build the library**:
```
npm run build:lib
```
**4. Run the application**:
```
ng serve
```
## Basic Usage
**1. Import the UI module**:
```typescript
import { DynamicFormsMaterialUIModule } from "@ng-dynamic-forms/ui-material";
@NgModule({
imports: [
ReactiveFormsModule,
DynamicFormsMaterialUIModule
]
})
export class AppModule {}
```
**2. Define your form model**:
```typescript
import {
DynamicFormModel,
DynamicCheckboxModel,
DynamicInputModel,
DynamicRadioGroupModel
} from "@ng-dynamic-forms/core";
export const MY_FORM_MODEL: DynamicFormModel = [
new DynamicInputModel({
id: "sampleInput",
label: "Sample Input",
maxLength: 42,
placeholder: "Sample input"
}),
new DynamicRadioGroupModel({
id: "sampleRadioGroup",
label: "Sample Radio Group",
options: [
{label: "Option 1", value: "option-1"},
{label: "Option 2", value: "option-2"},
{label: "Option 3", value: "option-3"}
],
value: "option-3"
}),
new DynamicCheckboxModel({
id: "sampleCheckbox",
label: "I do agree"
})
];
```
**3. Create a** `FormGroup` **via** `DynamicFormService`:
```typescript
import { MY_FORM_MODEL } from "./my-dynamic-form.model";
import { DynamicFormModel, DynamicFormService } from "@ng-dynamic-forms/core";
export class MyDynamicFormComponent {
formModel: DynamicFormModel = MY_FORM_MODEL;
formGroup = this.formService.createFormGroup(this.formModel);
constructor(private formService: DynamicFormService) {}
}
```
**4. Add a** `DynamicFormComponent` **to your template and bind its** `[group]` **and** `[model]` **property**:
```html
```
## UI Modules
NG Dynamic Forms is built to provide **solid yet unobtrusive** support for a variety of common UI libraries:
* **[Basic](https://github.com/udos86/ng-dynamic-forms/tree/master/projects/ng-dynamic-forms/ui-basic)**
* **[Foundation](https://github.com/udos86/ng-dynamic-forms/tree/master/projects/ng-dynamic-forms/ui-foundation)**
* **[Ionic](https://github.com/udos86/ng-dynamic-forms/tree/master/projects/ng-dynamic-forms/ui-ionic)**
* **[Material](https://github.com/udos86/ng-dynamic-forms/tree/master/projects/ng-dynamic-forms/ui-material)**
* **[NG Bootstrap](https://github.com/udos86/ng-dynamic-forms/tree/master/projects/ng-dynamic-forms/ui-ng-bootstrap)**
* **[ngx-bootstrap](https://github.com/udos86/ng-dynamic-forms/tree/master/projects/ng-dynamic-forms/ui-ngx-bootstrap)**
* **[PrimeNG](https://github.com/udos86/ng-dynamic-forms/tree/master/projects/ng-dynamic-forms/ui-primeng)**
You can instantly plug in your favorite form controls by **installing the appropriate
package and its peer dependencies**:
```
npm i @ng-dynamic-forms/ui- -S
```
**Now just import the UI module**:
```typescript
@NgModule({
imports: [
ReactiveFormsModule,
DynamicFormsMaterialUIModule
]
})
export class AppModule {}
```
For creating the form markup all UI modules come with a `DynamicFormComponent` that **can easily be added** to
your component template:
```html
```
Alternatively you can **directly make use of a specific** `DynamicFormControlComponent` to gain more control over rendering:
```html
```
Due to technical restrictions or external dependencies still being in development the support of major form controls
varies among UI packages. **See the following compatibility table**:
| | ui-basic | ui-ngx-bootstrap | ui-foundation | ui-ionic | ui-material | ui-ng-bootstrap | ui-primeng |
|---------------- |:--------: |:----------------: |:-------------: |:--------: |:-----------: |:---------------: |:----------: |
| Checkbox | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Checkbox Group | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Colorpicker | **** | ✗ | **** | **** | **** | **** | ✓ |
| Datepicker | * | ✓ | * | ✓ | * | ✓ | ✓ |
| Editor | ✗ | ✗ | ✗ | ✗ | ✗ | ✗ | ✓ |
| File Upload | ** | ** | ** | ✗ | ** | ** | ** |
| Input | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Radio Group | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Rating | ✗ | ✓ | ✗ | ✗ | ✗ | ✗ | ✓ |
| Select | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Slider | *** | *** | *** | ✓ | ✓ | *** | ✓ |
| Switch | ✗ | ✗ | ✓ | ✓ | ✓ | ✗ | ✓ |
| Textarea | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Timepicker | * | ✓ | * | ✓ | * | ✓ | ✓ |
**\*)** datetime controls can be achieved using a `DynamicInputModel` with `inputType: "date"` or `inputType: "time"`
**\*\*)** file upload controls can be achieved using a `DynamicInputModel` with `inputType: "file"`
**\*\*\*)** slider controls can be achieved using a `DynamicInputModel` with `inputType: "range"`
**\*\*\*\*)** color picker controls can be achieved using a `DynamicInputModel` with `inputType: "color"`
## Form Groups
In order to improve clarity it's often considered good practice to group forms into several logical `fieldset` sections.
Thus NG Dynamic Forms supports nesting of form groups out of the box!
**1. Declare a** `DynamicFormGroupModel` within your form model and **add it's models to the** `group` **array**:
```typescript
export const MY_FORM_MODEL: DynamicFormModel = [
new DynamicFormGroupModel({
id: "fullName",
legend: "Name",
group: [
new DynamicInputModel({
id: "firstName",
label: "First Name"
}),
new DynamicInputModel({
id: "lastName",
label: "Last Name"
})
]
}),
new DynamicFormGroupModel({
id: "address",
legend: "Address",
group: [
new DynamicInputModel({
id: "street",
label: "street"
}),
new DynamicInputModel({
id: "zipCode",
label: "Zip Code"
})
]
})
];
```
**2. Create a** `FormGroup` **and add a** `DynamicFormComponent`:
```typescript
formGroup = this.formService.createFormGroup(this.formModel);
```
```html
```
**3. To manipulate an existing** `DynamicFormGroupModel` **you can simply use** `DynamicFormService`:
* `addFormGroupControl(...)`
* `insertFormGroupControl(...)`
* `moveFormGroupControl(...)`
* `removeFormGroupControl(...)`
## Form Arrays
Sometimes forms need to allow the user to dynamically add multiple items of the same kind to it, e.g. addresses, products and so on.
Particularly for this reason Angular provides so called [**Form Arrays**](https://scotch.io/tutorials/how-to-build-nested-model-driven-forms-in-angular-2).
Fortunately, NG Dynamic Forms is capable of managing such nested form structures!
**1. Add a** `DynamicFormArrayModel` **to your form model**:
```typescript
export const MY_FORM_MODEL: DynamicFormModel = [
new DynamicFormArrayModel({
id: "myFormArray"
})
];
```
**2. Add the** `groupFactory` **property** to the `DynamicFormArrayModel` **and assign a function** to it which **returns
the structure** of a single form array item:
```typescript
new DynamicFormArrayModel({
id: "myFormArray",
initialCount: 5,
groupFactory: () => {
return [
new DynamicInputModel({
id: "myInput",
label: "My Input"
})
];
}
})
```
**3. Create a** `FormGroup` **via** `DynamicFormService` **and bind it to your component template**:
```typescript
this.formGroup = this.formService.createFormGroup(this.formModel);
```
```html
Add item
Remove all items
```
**4. You can now easily modify your form array with** `DynamicFormService`:
```typescript
ngOnInit() {
this.formArrayModel = this.formService.findModelById("myFormArray", this.formModel);
this.formArrayControl = this.formService.findControlByModel(this.formArrayModel, this.formGroup);
}
addItem() {
this.formService.addFormArrayGroup(this.formArrayControl, this.formArrayModel);
this.formService.detectChanges();
}
clear() {
this.formService.clearFormArray(this.formArrayControl, this.formArrayModel);
this.formService.detectChanges();
}
```
Never forget to trigger change detection via `detectChanges` when updating a form at runtime!
Alright, works like a charm!
But what if we want to append an additional remove `` for each array group?
Particularly for this case you can add a `` and **declare some custom content** that is **rendered equally for all form array groups**:
```html
Label
```
Whenever a `` is applied to a `DynamicFormArrayModel`, `NgTemplateOutletContext` **is internally bound to
the associated** `DynamicFormArrayGroupModel`.
That means **you can access the group object and it's properties by either declaring a local default template variable** or individual local template variables.
> see chapter on [Custom Templates](#custom-templates)
```html
Remove Item
Add Item
```
This is extremely useful when you'd like to implement a remove or insert function:
```typescript
removeItem(context: DynamicFormArrayModel, index: number) {
this.formService.removeFormArrayGroup(index, this.formArrayControl, context);
this.formService.detectChanges();
}
insertItem(context: DynamicFormArrayModel, index: number) {
this.formService.insertFormArrayGroup(index, this.formArrayControl, context);
this.formService.detectChanges();
}
```
Using `DynamicFormService` again, **you can even change the order of the groups** in a form array dynamically:
```typescript
this.formService.moveFormArrayGroup(index, -1, this.formArrayControl, context);
this.formService.detectChanges();
```
## Form Layouts
When using a NG Dynamic Forms UI package, e.g. `ui-bootstrap`, **all essential** form classes of the underlying CSS library
(like `form-group` or `form-control`) are automatically put in place for you in the template of the corresponding `DynamicFormControlComponent`.
Apart from that, NG Dynamic Forms does not make any further presumptions about optional CSS classes and leaves advanced layouting all up to you. That's **solid** yet **unobtrusive**.
So let's say we want to implement a beautifully aligned Bootstrap [horizonal form](http://getbootstrap.com/css/#forms-horizontal)...
At first we have to append the mandatory Bootstrap CSS class `form-horizontal` to the `` element in our template:
```html
```
Now we need to position the `` and the `form-control` using the Bootstrap [grid system](http://getbootstrap.com/css/#grid).
But since all the template logic for the form controls is capsuled in the component scope we cannot directly attach those necessary CSS classes to markup.
Don't worry!
Arbitrary CSS classes can be provided for any form control by binding a `DynamicFormLayout` to a `DynamicFormControlComponent`.
A `DynamicFormLayout` is a simple object literal that associates a CSS class configuration object with a model id.
By differentiating between `element` and `grid `context NG Dynamic Forms can automatically apply the
CSS class strings in the component template based on [position identifiers](https://github.com/udos86/ng-dynamic-forms/blob/master/projects/ng-dynamic-forms/core/src/lib/model/misc/dynamic-form-control-layout.model.ts):
```typescript
export const MY_FORM_LAYOUT = {
"myFormControlModelId": {
element: {
label: "control-label"
},
grid: {
control: "col-sm-9",
label: "col-sm-3"
}
},
"myOtherFormControlModelId": {
element: {
label: "control-label"
},
grid: {
control: "col-sm-9",
label: "col-sm-3"
}
}
};
```
To reference this `DynamicFormLayout` we now just create another component class member:
```typescript
import { MY_FORM_LAYOUT } from "./my-dynamic-form.layout";
export class MyDynamicFormComponent implements OnInit {
formModel: DynamicFormModel = MY_FORM_MODEL;
formLayout: DynamicFormLayout = MY_FORM_LAYOUT;
formGroup = this.formService.createFormGroup(this.formModel);
constructor(private formService: DynamicFormService) {}
}
```
Finally we pass the form layout to our `DynamicFormComponent` via input binding:
```html
```
Using this approach we are able to strictly decouple layout information from pure form models.
## Form Control Configuration
No matter which UI library you're using, usually there is a set of basic properties that apply universally to a certain type of form control.
So, when picking e.g. a slider component, you'll always find an `@Input()` to control its minimum / maximum value and its orientation.
Whenever that's the case NG Dynamic Forms directly provides an abstract configuration property on the corresponding `DynamicFormControlModel`:
```typescript
new DynamicSliderModel({
id: "mySlider",
min: 0,
max: 10,
vertical: true
})
```
Furthermore, very often there are additional component features that are totally library-specific.
So, when using e.g. Material there is a unique `@Input()` for inverting a slider component.
NG Dynamic Forms gives you the freedom to utilize such an individual parameter, as well.
All you need to do is to put it in the `additional` configuration object of your `DynamicFormValueControlModel`:
```typescript
new DynamicSliderModel({
id: "mySlider",
min: 0,
max: 10,
vertical: true
additional: {
invert: true
}
})
```
## Form Control Events
When developing forms it's often useful to keep track of certain events that occur on a specific form control.
With NG Dynamic Forms you can directly listen to the three most common events,
`blur`, `change` and `focus`, both on `DynamicFormControlComponent` and `DynamicFormComponent`:
```html
```
```html
```
The object passed to your handler function gives you any control and model information needed for further processing.
The `$event` property even grants access to the original event:
```typescript
interface DynamicFormControlEvent {
$event: Event | FocusEvent | DynamicFormControlEvent | any;
context: DynamicFormArrayGroupModel | null;
control: FormControl;
group: FormGroup;
model: DynamicFormControlModel;
type: string;
}
```
But when using a UI library usually there are a bunch of additional events provided for certain form control components.
Of course, NG Dynamic Forms won't let you down here.
All custom UI events are pooled by an individual `@Output()` utilizing the respective library prefix.
```html
```
## Updating Form Controls
NG Dynamic Forms entirely relies on the Angular `ReactiveFormsModule`.
Therefore the `value` property of a `DynamicFormValueControlModel` **cannot be two-way-bound** via `[(ngModel)]`.
Also, dating back to RC.6, Angular [**does not allow**](https://github.com/angular/angular/issues/11271) property bindings of the `disabled` attribute in reactive forms.
Yet updating either the value or status of a form control at runtime can easily be achieved.
At first we need to get a reference to its `DynamicFormControlModel` representation:
```typescript
const inputModel = this.formService.findModelById("myInput", this.formModel);
```
After that we just bring the convenient `value` and `disabled` setters of `DynamicFormValueControlModel` into play and we're fine:
```typescript
inputModel.value = "New Value";
inputModel.disabled = true;
```
The modifications immediately are reflected in the user interface. So far so good.
But what about other data? Since a `DynamicFormControlModel` is bound directly to a `DOM` element via Angular core mechanisms,
changing one of its properties should automatically trigger an update of the user interface as well, right?
Now **BEWARE**!
Due to performance reasons NG Dynamic Forms makes use of `ChangeDetectionStrategy.OnPush` under the hood.
Therefore changing any property on a `DynamicFormControl` except for `value` and `disabled` will not cause an automatic DOM update to occur.
Instead you always have to call `detectChanges()` on `DynamicFormService` after updating the model to signal that the library should manually trigger a change detection.
```typescript
inputModel.label = "New Label";
this.formService.detectChanges();
```
To optimize this you can optionally pass a `DynamicFormComponent` to `detectChanges()` to narrow the number of elements that are affected by the forthcoming change detection:
```typescript
@ViewChild(DynamicMaterialFormComponent, {static: true}) formComponent°!: DynamicMaterialFormComponent;
//...
this.formService.detectChanges(this.formComponent);
```
## Custom Templates
As already mentioned, NG Dynamic Forms gives you a lot of freedom in adjusting your form layout via CSS classes.
However there are situations where you would like to add custom markup for some of your form controls, as well.
In order to do so, just **put a** `` **inside your dynamic form control element** and **set a** `modelId` **property** to assign it to a certain control.
```html
Some custom markup
```
Alternatively **you can also apply** `modelType` **instead of** `modelId` **to reuse a template** for several form controls of the same type:
```html
Just some custom markup
```
**And it's getting better!**
Since for every template `NgTemplateOutletContext` is internally bound to the corresponding `DynamicFormControlModel` **you
can use local template variables to reference your models' properties**:
```html
Some custom markup for {{ id }}
```
Finally **you can determine whether the template is rendered before or after the actual form control** by using the `align` property:
```html
Some custom markup
```
## Custom Validators
Adding built-in Angular validators to any `DynamicFormControlModel` is plain and simple!
Just reference a function from `Validators` class by it's name in the `validators` or `asyncValidators` configuration object:
```typescript
new DynamicInputModel({
id: "myInput",
label: "My Input",
validators: {
required: null,
minLength: 3
}
})
```
So far so good!
But what if you'd like to introduce some custom validator as well?
```typescript
export function myCustomValidator(control: AbstractControl): ValidationErrors | null {
const hasError = control.value ? (control.value as string).startsWith("abc") : false;
return hasError ? {myCustomValidator: true} : null;
}
```
Just **provide your validator functions via default** `NG_VALIDATORS` **or** `NG_ASYNC_VALIDATORS` **token**:
```typescript
@NgModule({
// ...
providers: [
{provide: NG_VALIDATORS, useValue: myCustomValidator, multi: true}
]
})
```
> **Note:** thoughtram.io - [Custom Validators in Angular 2](http://blog.thoughtram.io/angular/2016/03/14/custom-validators-in-angular-2.html)
**You're now ready to apply your custom validator to your model**:
```typescript
new DynamicInputModel({
id: "myInput",
label: "My Input",
validators: {
myCustomValidator: null
}
})
```
**But beware! There's a catch!**
Internally NG Dynamic Forms resolves a provided validator by it's function name.
Though **when uglifying code** for production this **information is irretrievably lost**.
To save you from this issue NG Dynamic Forms comes up with **a special** `InjectionToken>` **named** `DYNAMIC_VALIDATORS` to which **you should additionally provide** any custom validator function:
```typescript
providers: [
{
provide: NG_VALIDATORS,
useValue: myCustomValidator,
multi: true
},
{
provide: DYNAMIC_VALIDATORS,
useValue: new Map([
["myCustomValidator", myCustomValidator]
])
}
]
```
You can also have multiple validators on the same input bu providing multiple key|value pairs in the useValue:
```typescript
providers: [
{
provide: NG_VALIDATORS,
useValue: myCustomValidator,
multi: true
},
{
provide: NG_VALIDATORS,
useValue: myOtherCustomValidator,
multi: true
},
{
provide: DYNAMIC_VALIDATORS,
useValue: new Map([
["myCustomValidator", myCustomValidator],
["myOtherCustomValidator", myOtherCustomValidator]
])
}
]
```
Another suitable solution for most situations would be to **make use of the alternate validator notation**:
```typescript
new DynamicInputModel({
id: "myInput",
label: "My Input",
validators: {
myCustomValidator: {
name: myCustomValidator.name,
args: null
}
}
})
```
## Custom Form Controls
Starting with version 6 NG Dynamic Forms allows you to easily plugin in your own custom form controls.
Beforehand follow [**the standard procedure**](https://blog.thoughtram.io/angular/2016/07/27/custom-form-controls-in-angular-2.html) to build your custom Angular form control:
```typescript
import { Component, forwardRef } from '@angular/core';
import { ControlValueAccessor, NG_VALUE_ACCESSOR } from "@angular/forms";
@Component({
selector: 'my-custom-form-control',
templateUrl: './my-custom-form-control.component.html',
providers: [
{
provide: NG_VALUE_ACCESSOR,
useExisting: forwardRef(() => MyCustomFormControlComponent),
multi: true
}
]
})
export class MyCustomFormControlComponent implements ControlValueAccessor {
//...
}
```
Now **create a new** `DynamicFormControlComponent`:
```typescript
import { ChangeDetectionStrategy, Component, EventEmitter, Input, Output, ViewChild } from "@angular/core";
import { FormGroup } from "@angular/forms";
import {
DynamicFormControlComponent,
DynamicFormControlCustomEvent,
DynamicFormLayout,
DynamicFormLayoutService,
DynamicFormValidationService,
} from "@ng-dynamic-forms/core";
import { MyCustomFormControlComponent } from "...";
@Component({
selector: "my-dynamic-custom-form-control",
templateUrl: "./my-dynamic-custom-form-control.component.html",
changeDetection: ChangeDetectionStrategy.OnPush
})
export class MyDynamicCustomFormControlComponent extends DynamicFormControlComponent {
@Input() group!: FormGroup;
@Input() layout?: DynamicFormLayout;
@Input() model!: /* corresponding DynamicFormControlModel */;
@Output() blur: EventEmitter = new EventEmitter();
@Output() change: EventEmitter = new EventEmitter();
@Output() customEvent: EventEmitter = new EventEmitter();
@Output() focus: EventEmitter = new EventEmitter();
@ViewChild(MyCustomFormControlComponent) myCustomFormControlComponent!: MyCustomFormControlComponent;
constructor(protected layoutService: DynamicFormLayoutService,
protected validationService: DynamicFormValidationService) {
super(layoutService, validationService);
}
}
```
Next **embed your custom form control** into the component template:
```html
```
Then **add your newly implemented** `DynamicFormControl` **to** `entryComponents` in your app module:
```typescript
entryComponents: [MyDynamicCustomFormControlComponent]
```
Finally **provide** `DYNAMIC_FORM_CONTROL_MAP_FN` **to overwrite the default mapping** of a concrete `DynamicFormControlModel` to its corresponding `DynamicFormControlComponent`;
```typescript
providers: [
{
provide: DYNAMIC_FORM_CONTROL_MAP_FN,
useValue: (model: DynamicFormControlModel): Type | null => {
switch (model.type) {
case /* corresponding DynamicFormControlModel */:
return MyDynamicCustomFormControlComponent;
}
}
}
]
```
## Validation Messaging
Delivering meaningful validation information to the user is an essential part of good form design.
Yet HTML5 already comes up with some [native functionality](https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Forms/Data_form_validation)
you very likely want to use [Angular mechanisms](http://blog.thoughtram.io/angular/2016/03/14/custom-validators-in-angular-2.html)
to gain much more control over validation logic and it's corresponding message output.
Avoiding a library too opinionated in the beginning, NG Dynamic Forms has originally been developed without any kind of obtrusive validation message system in mind.
However, due to its very common use case, model-based error messaging has eventually become an optional **built-in feature**.
**Just add an** `errorMessages` **object to any** `DynamicFormControlModel` and **assign error message templates based on** `Validators` **names**:
```typescript
new DynamicInputModel({
id: "myInput",
label: "My Input",
validators: {
required: null
},
errorMessages: {
required: "{{ label }} is required."
}
})
```
**Note:** Error message templates allow the following placeholders:
* `{{ propertyName }}` where `propertyName` is a property of the model, for example `{{ label }}`.
* `{{ validator.propertyName }}` where `propertyName` is a property of the object returned by validation function, for example `{{ validator.requiredPattern }}` in case of pattern validator.
**Error messaging is automatically enabled whenever** `errorMessages` **are declared on a** `DynamicFormControlModel`.
By default error messages are shown whenever the corresponding form control is invalid and blurred at the same time and has already been touched.
Since the condition for displaying error messages often is a subject to individual user experience preferences you can customize this by
providing a so called `DynamicErrorMessagesMatcher` via the `DYNAMIC_ERROR_MESSAGES_MATCHER` injection token:
```ts
export const MY_CUSTOM_ERROR_MESSAGES_MATCHER =
(control: AbstractControl, model: DynamicFormControlModel, hasFocus: boolean) => {
return //...
};
// ...
providers: [
{
provide: DYNAMIC_ERROR_MESSAGES_MATCHER,
useValue: myCustomErrorMessagesMatcher
},
]
```
By default the `DEFAULT_ERROR_STATE_MATCHER` is active:
```ts
export const DEFAULT_ERROR_STATE_MATCHER: DynamicErrorMessagesMatcher =
(control: AbstractControl, model: DynamicFormControlModel, hasFocus: boolean) => {
return control.touched && !hasFocus;
};
```
Please note here that NG Dynamic Forms always assumes both the control being invalid and error messages being defined on the model
as a fixed precondition.
## Related Form Controls
In many forms the state of a certain form control directly depends on the `value` or `status` of some other form control.
Implementing such a connection manually would be time-consuming and only lead to undesired boilerplate code.
NG Dynamic Forms enables you to declaratively add form control relations by using so called `DynamicFormControlMatcher`s.
A matcher defines the action that should take place for a predefined `match` when a `value` or `state` change has occured on the related form control.
```typescript
export interface DynamicFormControlMatcher {
match: string;
opposingMatch: string | null;
onChange(hasMatch: boolean, model: DynamicFormControlModel, control: FormControl, injector: Injector): void;
}
```
At the moment there are the following **default matchers** available:
* `DisabledMatcher`
* `HiddenMatcher`
* `RequiredMatcher`
**NOTE: Always make sure that you're providing every** `DynamicFormControlMatcher` **in your** `app.module`:
```typescript
providers: [
// ...
DISABLED_MATCHER,
REQUIRED_MATCHER
]
```
That way you're also totally **free to implement your own custom matcher**:
```typescript
export const MyCustomMatcher: DynamicFormControlMatcher = {
match: MATCH_CUSTOM,
opposingMatch: MATCH_CUSTOM_OPPOSITE,
onChange(hasMatch: boolean, model: DynamicFormControlModel): void {
if (hasMatch) {
console.log("It's a match");
}
}
};
```
```typescript
export const MY_CUSTOM_MATCHER: ValueProvider = {
provide: DYNAMIC_MATCHERS,
useValue: MyCustomMatcher,
multi: true
};
```
So let's pretend we need to have our textarea `myTextArea` disabled as soon as the third option of our select menu `mySelect` is chosen.
Just add a `relations` property to your `DynamicFormControlModel`, then declare a `DynamicFormControlRelation` by setting a `match` for a certain `DynamicFormControlCondition`:
```typescript
new DynamicTextAreaModel(
{
id: "myTextArea",
label: "My Textarea",
relations: [
{
match: MATCH_DISABLED,
when: [{ id: "mySelect", value: "option-3" }]
}
]
}
```
**That's it** - the library will automatically add all the pieces together under the hood.
*But what if `myTextArea` should depend on another control `myRadioGroup` as well?*
Luckily there's support for **multi-related form controls**, too.
Just add a second `DynamicFormControlCondition` entry and (optionally) define how all conditions should logically be connected via `operator`:
```typescript
new DynamicTextAreaModel(
{
id: "myTextArea",
label: "My Textarea",
relations: [
{
match: MATCH_DISABLED,
operator: AND_OPERATOR,
when: [
{ id: "mySelect", value: "option-3" },
{ id: "myRadioGroup", value: "option-4" }
]
}
]
}
)
```
## JSON Export & Import
Sooner or later you likely want to persist your dynamic form model in order to restore it at some point in the future.
That's why all `DynamicFormControlModel`s have been prepared to **properly export to JSON**:
```typescript
storeForm() {
const json = JSON.stringify(this.formModel);
// ...store JSON in localStorage or transfer to server
}
```
In order to recreate a form from JSON just make use of the corresponding function provided by `DynamicFormService`:
```typescript
restoreForm() {
let json: string;
// ...load JSON from localStorage or server
this.formModel = this.formService.fromJSON(json);
}
```
## JSON Form Models
By default NG Dynamic Forms **embraces prototypical inheritance** and forces you to use constructor functions when modelling a form.
Depending on your general set-up or individual preferences sometimes it's more suitable to provide a form model in plain JSON, though.
Fortunately, **this is perfectly fine and supported**, as well.
To specify a single JSON form control model just **assign the mandatory** `type` **property**:
```typescript
[
{
"type": "INPUT",
"id": "sampleInput",
"label": "Sample Input",
"maxLength": 42,
"placeholder": "Sample input"
},
{
"type": "RADIO_GROUP",
"id": "sampleRadioGroup",
"label": "Sample Radio Group",
"options": [
{"label": "Option 1", "value": "option-1"},
{"label": "Option 2", "value": "option-2"},
{"label": "Option 3", "value": "option-3"}
],
"value": "option-3"
},
{
"type": "CHECKBOX",
"id": "sampleCheckbox",
"label": "I do agree"
}
]
```
After having asynchronously loaded the JSON form model into your application **don't forget to transform it** via `fromJSON()` **before creating** a `FormGroup`.
```typescript
ngOnInit() {
this.http.get('./app/my-dynamic-form.model.json').subscribe(formModelJson => {
this.formModel = this.formService.fromJSON(formModelJson);
this.formGroup = this.formService.createFormGroup(this.formModel);
});
}
```
## Text Masks
Whenever an `` element needs to be filled in a predefined format, text masks can make a nice form enhancement.
Since Angular does not deliver an appropriate feature by default, NG Dynamic Forms integrates [**ngx-mask**](https://github.com/JsDaddy/ngx-mask).
That's why some UI packages demand one additional peer dependency to be installed:
```
npm install ngx-mask --save
```
You're now capable of adding a `mask` property to any `DynamicInputModel` according to [Text Mask docs](https://github.com/text-mask/text-mask/blob/master/componentDocumentation.md#mask):
```typescript
new DynamicInputModel({
id: "maskedInput",
label: "Masked Input",
mask: "00/00/0000",
})
```
Furthermore, you can add additional configuration via `maskConfig` according to the ngx-mask
```typescript
new DynamicInputModel({
id: "maskedInput",
label: "Masked Input",
mask: "00/00/0000",
maskConfig: {
showMaskTyped: true
},
})
```
**Note:** Angular does not support adding multiple custom value accessors to the same input element. Thus, this feature is **not** available to libraries like Material that already do apply a custom value accessor by default.
In cases like Prime NG where a component library natively provides some text mask mechanism, NG Dynamic Forms maps the mask configuration to the built-in api.
## Autocompletion
Adding automatic input completion can be key factor to good user experience (especially on mobile devices) and should always
be considered when designing forms.
That's why NG Dynamic Forms keeps you covered here, as well!
Following HTML5 [standard behavior](http://www.w3schools.com/tags/att_form_autocomplete.asp), the `autocomplete` attribute is always bound to `on` for any `DynamicFormTextInputControl` form element by default.
Nevertheless you can completely disable this feature by explicitly setting the corresponding model property to `off`:
```typescript
import { AUTOCOMPLETE_OFF } from "@ng-dynamic-forms/core";
const model = new DynamicInputModel({
id: "myInput",
label: "My Input",
autoComplete: AUTOCOMPLETE_OFF
});
```
Further on NG Dynamic Forms embraces the brand new HTML5
[**autofill detail tokens**](https://html.spec.whatwg.org/multipage/forms.html#autofill) by providing
`AUTOFILL_` string constants and `AutoFillUtils` to help you putting together a valid expression:
> **Note:** Jason Grigsby - [Autofill: What web devs should know, but don’t](https://cloudfour.com/thinks/autofill-what-web-devs-should-know-but-dont/)
```typescript
import {
AutoFillUtils,
AUTOFILL_TOKEN_BILLING,
AUTOFILL_FIELD_NAME,
AUTOCOMPLETE_ON
} from "@ng-dynamic-forms/core";
export class MySample {
constructor() {
const expression = `${AUTOFILL_TOKEN_BILLING} ${AUTOFILL_FIELD_NAME}`;
const model = new DynamicInputModel({
id: "myInput",
label: "My Input",
autoComplete: AutoFillUtils.validate(expression) ? expression : AUTOCOMPLETE_ON
});
}
}
```
Besides you can make user input more comfortable, providing HTML5 [**datalists**](http://www.w3schools.com/tags/tag_datalist.asp)
by setting the `list` property of `DynamicInputControlModel`:
```typescript
new DynamicInputModel({
id: "myInput",
label: "My Input",
list: ["Alabama", "Alaska", "Arizona", "Arkansas"]
})
```
## FAQ
> **Why should I use NG Dynamic Forms?**
Your Angular forms will become highly maintainable as you don't have to care about keeping template markup and program code in sync ever again.
> **When should I use NG Dynamic Forms?**
Whenever your Angular application is driven by multiple complex forms.
> **When should I not use NG Dynamic Forms?**
Whenever your Angular application has to display very simple forms only or extremely individual form UI.
> **Are there any downsides to using NG Dynamic Forms?**
Certain limitations exist regarding extremely individual form layouts.
> **Does NG Dynamic Forms support custom form controls?**
Yes, [it does](#custom-form-controls).
> **Are there any other dynamic forms libraries for Angular?**
Yes, namely [ng-formly](https://github.com/formly-js/ng-formly), [ngx-forms](https://github.com/ngx-plus/ngx-forms) and [angular-formio](https://github.com/formio/angular-formio).
> **How can I support this project besides contributing issues or code?**
[Star](https://github.com/udos86/ng-dynamic-forms/stargazers) the repository.
## Appendix
* Logo design made by [**oscarana**](http://www.oscarana-art.com)