Implement a custom validator using remote module

Level: intermediate

Example

Add a validator that ensures the Name field of the custom Requests section starts from the REQ- prefix. 

Implement the validator using a remote module created in Angular framework.

1. Create an Angular project to develop a custom validator using remote module

To create an Angular project to develop a custom validator using remote module, follow the instruction in a separate article: Implement custom UI component using remote module.

2. Create a custom validator using remote module

1. Create an Angular class in the project. To do this, run the ng g class verify-request-name.validator command at the command line terminal of Microsoft Visual Studio Code.

   As a result, Microsoft Visual Studio Code will add the VerifyRequestNameValidator class files to the src/app/ project directory.

2. Implement the validator.

   1. Open the verify-request-name.validator.ts file.
   2. Flag the VerifyRequestNameValidator class using the @CrtValidator decorator.
   3. Inherit the BaseValidator class from the @creatio-devkit/common library.
   4. Implement the field async.
   5. Implement the abstract method validate() that validates data in the field.
   6. Import the required functionality from the libraries into the class.
   7. Save the file.
   verify-request-name.validator.ts file

   /* Import the required functionality from the libraries. */
   import { BaseValidator, CrtControlState, CrtInject, CrtValidationErrors, CrtValidator, ValidatorParametersValues } from '@creatio-devkit/common';
   
   /* Add the CrtValidator decorator to the VerifyRequestNameValidator interface. */
   @CrtValidator({
       type: 'usr.VerifyRequestNameValidator',
   })
   
   export class VerifyRequestNameValidator extends BaseValidator {
       
       constructor(private _prefix: string) {
           super();
       }
   
       protected override async = false;
   
       public validate(
           control: CrtControlState,
           params?: ValidatorParametersValues
       ): CrtValidationErrors | null {
           const value = control.value as string;
           const maxLength = (params as any).maxLength;
           if (value && (!value.startsWith(this._prefix) || value.length > maxLength)) {
               return {
                   error: {
                       message: 'Add "REQ-" prefix'
                   },
               };
           }
           return null;
       }
   }

3. Inject dependencies.

   1. Open the verify-request-name.validator.ts file.
   2. Create the REQUEST_NAME_PREFIX instance of the InjectionToken class. Use the token to work with Angular DI (dependency injection). 
   3. Mark DI in the constructor of the VerifyRequestNameValidator class using the @CrtInject decorator.
   4. Import the required functionality from the libraries into the class.
   5. Save the file.
   verify-request-name.validator.ts file

   /* Import the required functionality from the libraries. */
   ...
   import { InjectionToken } from "@angular/core";
   
   /* The REQUEST_NAME_PREFIX token that works with Angular DI (dependency injection). */
   export const REQUEST_NAME_PREFIX = new InjectionToken<string>('REQUEST_NAME_PREFIX');
   
   ...
   
   export class VerifyRequestNameValidator extends BaseValidator {
       /* Mark DI in the constructor using the @CrtInject decorator. */
       constructor(@CrtInject(REQUEST_NAME_PREFIX) private _prefix: string) {
           super();
       }
       
   ...
   
   }

4. Register the VerifyRequestNameValidator validator as a validator and the REQUEST_NAME_PREFIX token.

   1. Open the app.module.ts file.

   2. Add the VerifyRequestNameValidator validator to the validators section in the CrtModule decorator.

   3. Add the configuration object to the providers section in the NgModule decorator.

      • Set the provide property to REQUEST_NAME_PREFIX.
      • Set the useValue property to the REQ.

   4. Implement the resolveDependency() method in the bootstrapCrtModule() method of the AppModule root module. The bootstrapCrtModule() method registers the VerifyRequestNameValidator validator flagged using the CrtModule decorator. The resolveDependency() method receives the dependencies of the VerifyRequestNameValidator converter.

   5. Import the required functionality from the libraries into the class.

   6. Save the file.

   app.module.ts file

   /* Import the required functionality from the libraries. */
   import { DoBootstrap, Injector, NgModule, ProviderToken } from '@angular/core';
   import { BrowserModule } from '@angular/platform-browser';
   import { bootstrapCrtModule, CrtModule } from '@creatio-devkit/common';
   import { VerifyRequestNameValidator, REQUEST_NAME_PREFIX } from "./verify-request-name.validator";
   
   @CrtModule({
     /* Specify that VerifyRequestNameValidator is a validator. */ 
     validators: [VerifyRequestNameValidator],
   })
   @NgModule({
     ...
     providers: [{
       provide: REQUEST_NAME_PREFIX,
       useValue: 'REQ-'
     }],
   
   })
   export class AppModule implements DoBootstrap {
     constructor(private _injector: Injector) { }
   
     ngDoBootstrap(): void {
       /* Bootstrap CrtModule definitions. */
       bootstrapCrtModule('sdk_remote_module_package', AppModule, {
         resolveDependency: (token) => this._injector.get(<ProviderToken<unknown>>token)
       });
     }
   }

5. Build the project. To do this, run the npm run build command at the command line terminal of Microsoft Visual Studio Code.

As a result, Microsoft Visual Studio Code will add the build to the dist directory of the Angular project. The build will have the sdk_remote_module_package name.

3. Add the validator implemented using remote module to the Freedom UI page

1. Set up the Freedom UI page.

   1. Repeat steps 1-7 of the procedure to implement custom UI component using remote module.
   2. Click the button in the action panel of the Freedom UI Designer. After you save the page settings, Creatio opens the source code of the Freedom UI page.

2. Bind the usr.VerifyRequestNameValidator validator to the model attribute in the viewModelConfigDiff schema section.

   viewModelConfigDiff schema section

   viewModelConfigDiff: /**SCHEMA_VIEW_MODEL_CONFIG*/{
       "attributes": {
           "UsrName": {
               "modelConfigDiff": {
                   "path": "PDS.UsrName"
               },
               "validators": {
                   "usr.VerifyRequestNameValidator": {
                       "type": "usr.VerifyRequestNameValidator",
                       "params": {
                           "maxLength": 10
                       }
                   }
               }
           },
           ...
       }
   }/**SCHEMA_VIEW_MODEL_CONFIG*/,

3. Click Save on the Client Module Designer’s toolbar.

As a result, Creatio will add the validator to the Freedom UI page.

Outcome of the example

To view the outcome of the example:

1. Open the Requests app page and click Run app.
2. Click New on the Requests app toolbar.
3. Enter "123" in the Name input. 

As a result, Creatio will display an error notification in a pop-up box. The validator is implemented using a remote module created in Angular framework. 

Source code

verify-request-name.validator.ts file

import {
    BaseValidator, CrtControlState, CrtInject,
    CrtValidationErrors,
    CrtValidator,
    ValidatorParametersValues
} from '@creatio-devkit/common';
import { InjectionToken } from "@angular/core";

export const REQUEST_NAME_PREFIX =
    new InjectionToken<string>('REQUEST_NAME_PREFIX');

@CrtValidator({
    type: 'usr.VerifyRequestNameValidator',
})

export class VerifyRequestNameValidator extends BaseValidator {

    constructor(@CrtInject(REQUEST_NAME_PREFIX) private _prefix: string) {
        super();
    }

    protected override async = false;

    public validate(
        control: CrtControlState,
        params?: ValidatorParametersValues
    ): CrtValidationErrors | null {
        const value = control.value as string;
        const maxLength = (params as any).maxLength;
        if (value && (!value.startsWith(this._prefix) || value.length > maxLength)) {
            return {
                error: {
                    message: 'Add "REQ-" prefix'
                },
            };
        }
        return null;
    }
}

app.module.ts file

import { DoBootstrap, Injector, NgModule, ProviderToken } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { bootstrapCrtModule, CrtModule } from '@creatio-devkit/common';
import { VerifyRequestNameValidator, REQUEST_NAME_PREFIX } from "./verify-request-name.validator";

@CrtModule({
  validators: [VerifyRequestNameValidator],
})
@NgModule({
  declarations: [],
  imports: [BrowserModule],
  providers: [{
  provide: REQUEST_NAME_PREFIX,
  useValue: 'REQ-'
}],

})
export class AppModule implements DoBootstrap {
  constructor(private _injector: Injector) { }

  ngDoBootstrap(): void {
    /* Bootstrap CrtModule definitions. */
    bootstrapCrtModule('sdk_remote_module_package', AppModule, {
      resolveDependency: (token) => this._injector.get(<ProviderToken<unknown>>token)
    });
  }
}

---

Resources

*.zip archive that contains the implemented Freedom UI app

Angular project that contains the implemented example