Services

/**
 * Service for managing global Formly configuration
 */
@Injectable({ providedIn: 'root' })
export class FormlyConfig {
  /** Extra configuration options */
  extras: FormlyConfigExtras;
  
  /**
   * Add configuration options to the global configuration
   * @param config - Configuration options to add
   */
  addConfig(config: ConfigOption): void;
  
  /**
   * Register field type(s) with the configuration system
   * @param options - Field type configuration or array of configurations
   */
  setType(options: TypeOption | TypeOption[]): void;
  
  /**
   * Register wrapper(s) with the configuration system
   * @param options - Wrapper configuration or array of configurations
   */
  setWrapper(options: WrapperOption | WrapperOption[]): void;
  
  /**
   * Register validator(s) with the configuration system
   * @param options - Validator configuration or array of configurations
   */
  setValidator(options: ValidatorOption | ValidatorOption[]): void;
  
  /**
   * Register validation message(s) with the configuration system
   * @param options - Validation message configuration or array of configurations
   */
  setValidationMessage(options: ValidationMessageOption | ValidationMessageOption[]): void;
  
  /**
   * Get field type configuration by name
   * @param name - Name of the field type or component type
   * @param throwIfNotFound - Whether to throw error if type not found
   * @returns Field type configuration
   */
  getType(name: FormlyFieldConfig['type'], throwIfNotFound?: boolean): TypeOption;
  
  /**
   * Get validator configuration by name
   * @param name - Name of the validator
   * @returns Validator configuration
   */
  getValidator(name: string): ValidatorOption;
  
  /**
   * Get wrapper configuration by name
   * @param name - Name of the wrapper or wrapper component type
   * @returns Wrapper configuration
   */
  getWrapper(name: string | Type<FieldWrapper>): WrapperOption;
  
  /**
   * Add validation message for a specific validator
   * @param name - Name of the validator
   * @param message - Message string or function
   */
  addValidatorMessage(name: string, message: ValidationMessageOption['message']): void;
  
  /**
   * Get validation message by validator name
   * @param name - Name of the validator
   * @returns Validation message
   */
  getValidatorMessage(name: string): ValidationMessageOption['message'];
  
  /** Map of registered field types */
  types: { [name: string]: TypeOption };
  
  /** Map of registered validators */
  validators: { [name: string]: ValidatorOption };
  
  /** Map of registered wrappers */
  wrappers: { [name: string]: WrapperOption };
  
  /** Map of registered validation messages */
  messages: { [name: string]: ValidationMessageOption['message'] };
  
  /** Map of registered extensions */
  extensions: { [name: string]: FormlyExtension };
}

import { Injectable, Component } from '@angular/core';
import { FormlyConfig, FieldType } from '@ngx-formly/core';

@Component({
  selector: 'custom-input',
  template: `<input [formControl]="formControl" [formlyAttributes]="field">`
})
export class CustomInputComponent extends FieldType {}

@Injectable()
export class MyConfigService {
  constructor(private formlyConfig: FormlyConfig) {
    this.setupConfiguration();
  }
  
  private setupConfiguration() {
    // Register custom field type
    this.formlyConfig.setType({
      name: 'custom-input',
      component: CustomInputComponent,
      wrappers: ['form-field']
    });
    
    // Register custom validator
    this.formlyConfig.setValidator({
      name: 'custom-validator',
      validation: (control) => {
        return control.value && control.value.length > 5 ? null : { customValidator: true };
      }
    });
    
    // Register validation message
    this.formlyConfig.setValidationMessage({
      name: 'custom-validator',
      message: 'This field must be longer than 5 characters'
    });
  }
}

/**
 * Service for building forms from field configurations
 */
@Injectable({ providedIn: 'root' })
export class FormlyFormBuilder {
  /**
   * Build form controls and structure from field configurations
   * @param form - The Angular FormGroup or UntypedFormGroup to build into
   * @param fields - Array of field configurations
   * @param model - The data model to bind to
   * @param options - Form options and lifecycle hooks
   */
  /**
   * Build and configure form controls for field configurations
   * @param field - Field configuration to build
   * @returns Processed field configuration
   */
  build(field: FormlyFieldConfigCache): FormlyFieldConfigCache;
}

import { Component, OnInit } from '@angular/core';
import { FormGroup } from '@angular/forms';
import { FormlyFormBuilder, FormlyFieldConfig, FormlyFormOptions } from '@ngx-formly/core';

@Component({
  selector: 'app-dynamic-form',
  template: `
    <form [formGroup]="form">
      <formly-form [form]="form" [fields]="fields" [model]="model" [options]="options">
      </formly-form>
    </form>
  `
})
export class DynamicFormComponent implements OnInit {
  form = new FormGroup({});
  model = {};
  fields: FormlyFieldConfig[] = [];
  options: FormlyFormOptions = {};
  
  constructor(private formBuilder: FormlyFormBuilder) {}
  
  ngOnInit() {
    this.fields = [
      {
        key: 'firstName',
        type: 'input',
        props: { label: 'First Name', required: true }
      },
      {
        key: 'lastName',
        type: 'input',
        props: { label: 'Last Name', required: true }
      }
    ];
    
    // Manually build the form (usually done automatically by FormlyForm component)
    this.formBuilder.buildForm(this.form, this.fields, this.model, this.options);
  }
}

interface FormlyConfigExtras {
  /** Whether to check expressions on form initialization */
  checkExpressionOn?: 'modelChange' | 'changeDetectionCheck';
  
  /** Whether to immediately render extensions */
  immutable?: boolean;
  
  /** Whether to show errors immediately */
  showError?: (field: FormlyFieldConfig) => boolean;
  
  /** Custom error state matcher */
  errorStateMatcher?: ErrorStateMatcher;
  
  /** Field transform function */
  fieldTransform?: (
    fields: FormlyFieldConfig[], 
    model: any, 
    form: FormGroup | UntypedFormGroup, 
    options: FormlyFormOptions
  ) => FormlyFieldConfig[];
  
  /** Whether to reset field values when hidden */
  resetFieldOnHide?: boolean;
  
  /** Whether to render fields when hidden */
  renderFormlyFieldElement?: boolean;
  
  /** Whether to remove form control when field is hidden */
  removeFormControlOnHide?: boolean;
  
  /** Class name to add to formly-field elements */
  formlyFieldElementClassName?: string;
  
  /** Whether to use legacy API */
  useLegacyAPI?: boolean;
}

interface ErrorStateMatcher {
  /**
   * Determine if field should show error state
   * @param control - The form control
   * @param form - The parent form
   * @returns True if error should be shown
   */
  isErrorState(control: AbstractControl | null, form: FormGroupDirective | NgForm | null): boolean;
}

interface FormlyFormOptions {
  /** Shared state object accessible to all fields */
  formState?: any;
  
  /** Subject for listening to field value changes */
  fieldChanges?: Subject<FormlyValueChangeEvent>;
  
  /** Function to transform fields before rendering */
  fieldTransform?: (
    fields: FormlyFieldConfig[], 
    model: any, 
    form: FormGroup | UntypedFormGroup, 
    options: FormlyFormOptions
  ) => FormlyFieldConfig[];
  
  /** Custom function to determine when to show field errors */
  showError?: (field: FormlyFieldConfig) => boolean;
  
  /** Whether to reset field values when fields are hidden */
  resetOnHide?: boolean;
  
  /** Parent form directive for nested forms */
  parentForm?: FormGroupDirective | null;
  
  /** Function to update initial values */
  updateInitialValue?: () => void;
  
  /** Function to check field expressions */
  checkExpressions?: (field: FormlyFieldConfig, ignoreCache?: boolean) => void;
  
  /** Function to trigger change detection */
  detectChanges?: (field: FormlyFieldConfig) => void;
  
  /** Function to build field configurations */
  build?: (field?: FormlyFieldConfig) => FormlyFieldConfig[];
  
  // Internal properties
  _resolver?: ComponentFactoryResolver;
  _viewContainerRef?: ViewContainerRef;
  _markForCheck?: (field: FormlyFieldConfig) => void;
  _hiddenFieldsForCheck?: FormlyFieldConfig[];
  _initialModel?: any;
}

interface FormlyValueChangeEvent {
  /** The field that triggered the change */
  field: FormlyFieldConfig;
  
  /** The field type that changed */
  type: string;
  
  /** The new value */
  value: any;
}