SB-forms Components & Configurations

List Of Components

Component	Description
Textbox	Component used to render textbox
Textarea	Component used to render textarea
Checkbox	Component used to render checkbox
Select	Component used to render dropdown with single select
MultiSelect	Component used to render dropdown with multi select
Topic Selector	Component used to render topic selector
Timer	Component used to render time
Keywords	Component used to render input tags
Framework	Component used to render dropdown with framework values
FrameworkCategorySelect	Component used to render dropdown with framework categories.

Field Configuration Properties

{
    "code": string, // property to match the backend schema ("name", "description", etc...)
    "name": string, // name of the field ("Name", "Board", "Medium", "License", "Copyright Year", etc)
    "label": string, // title of the field 
    "placeholder": string, // placeholder text to appear within the field
    "description": string, // to specify description about the field and to show as tooltip
    "default": string, // specify default value
    "dataType": string, // to specify the datatype of the field outcome ("list", "number", "text")
    "inputType": string, // to map the field type and the component ("text", "textarea", "select", "nestedselect", etc)
    "editable": boolean, // to enable or disable the field
    "required": boolean, // to specify if the field is mandatory or not (currently, not used.)
    "visible": boolean, // to hide or show the field 
    "depends": array, // array of "code" to specify that this field is dependant on other fields
    "range": array, // Array or array of objects of inputs to fields such as "select", "nestedselect", "multiselect"
    "options": array/function/map, // to specify the inputs to fields such as "select", "nestedselect", "multiselect", "framework", "frameworkCategorySelect"
    "renderingHints": json, // to specify any additional configuration ex:({"class": "sb-g-col-lg-1 required"})
    "validations": array // Array of objects to specity the validations of a field. Each validation object takes properties such as "type", "message", "value", "criteria"
    "output": string, // this field is specific to framework terms and it's associations. The field will decide the property for the field outcome ex:("name", "label", "identifier")
    "sourceCategory": string, // this field is specific to framework categories to map the category and association ex: (to map "subjectIds" with "subject" or to map "targetMediumIds" with "medium")
    "terms": array, // Array or array of object of inputs to fields related to framework and it's categories
}

Sample Configuration for `name` field:

{
    "code": "name",
    "name": "Name",
    "label": "Title",
    "placeholder": "Title",
    "description": "Name of the content",
    "dataType": "text",
    "inputType": "text",
    "editable": true,
    "required": true, // currently not used to check if the field is mandatory. //
    "visible": true,
    "renderingHints": {
        "class": "sb-g-col-lg-1 required"
    },
    "validations": [
        {
            "type": "max",
            "value": "120", // maximum number of characters
            "message": "Input is Exceeded"
        },
        {
            "type": "required", 
            "message": "Title is required"
        }
    ]
},

Custom invocation when a field’s value changes:

FORMCONTROL.valueChanges.pipe(
    tap((value) => {
      // custom logic
    })
);

Custom invocation when a dependant field values changes:

merge(..._.map([DependantFieldControl1, DependantFieldControl2], depend => depend.valueChanges)).pipe(
       tap((value) => {
      // custom logic
  })
)

Custom validation:

Let’s say we have two fields, maxTime and warningTime and assume that the condition here is warningTime should not be greater than maxTime

{
    "code": "maxTime",
    "dataType": "text",
    "name": "MaxTimer",
    "default": "3600",
    "renderingHints": {
        "class": "sb-g-col-lg-1 required"
    },
    "description": "MaxTime for the content",
    "inputType": "timer"
}

{
    "code": "warningTime",
    "dataType": "list",
    "name": "Warning Time",
    "depends": [
        "maxTime"
    ],
    "inputType": "timer",
    "validations": [
        {
            "type": "compare",
            "criteria": {
                "<": [
                    "maxTime"
                ]
            },
            "message": "warning time should be less than max timer"
        }
    ]
}

We introduced a new type of validations called compare:

{
    "type": "compare",
    "criteria": {
        "<": [
            "maxTime"
        ]
    },
    "message": "warning time should be less than max timer"
}

Here, criteria is a map which takes any comparison operator as the key and array of codes as value.

Following is our custom function to compare two fields and handle errors if any. The function takes two arguments - criteria and AbstractControl.

compareFields(criteria, control: AbstractControl): ValidationErrors | null {
    // your custom code to compare fields based on the criteria
}

Now the function can be passed to Angular by doing Validators.compose as shown below:

Validators.compose([compareFields.bind(this, criteria)])

Function compareFields will now be called whenever warningTime field is changes.

Custom Event Listener:

Angular by default provides two methods to listen to any field’s changes.

FormControl.valueChanges
FormControl.statusChanges

The above two methods will be immediately triggered when there is a change in the field.

Let’s assume we have a scenario where we need to make an async API call and make use of the API response, the above two methods will not help us as the API might have a delay.

To tackle this scenario, we will introduce a custom event emitter on the FormControl.

The following interface extends the default Angular FormControl and adds a RxJS Subject event emitter.

export interface CustomFormControl extends FormControl {
  customEventHandler$?: Subject<any>;
}

This will help us emit the event when the API returns a response

ObservableAPI..subscribe(
    (APIResponse) => {
        FORMCONTROL.customEventHandler$.next(APIResponse);
    }
  );
}

Any other fields that are dependant on this API response can now listen to this event emitter.

merge(_.map([DependantControl1, DependantControl2], depend => depend.customEventHandler$)).subscribe(
  (response) => {
    ...
  }, error => {
    ...
  }
)

IN PROGRESS

Closure function:

A closure function takes the following objects as its arguments.

control: FormControl // form control of the framework field
depends: [FormControl, FormControl], // array of formcontrols of the fields that the framework field depends on (if any)
formGroup: FormGroup // instance of the entire FormGroup
loading: anonymous function // to notify about the data loading status 
loaded: anonymous function // to notify about the data loaded status

Sample Closure function:

Let’s say we have a field called framework. On change of framework field, if we have to invoke a logic, it can be achieved as shown below:

During the initialisation of the framework field, we will pass the following function to options property of framework field.

getFramework(control, depends: FormControl[], formGroup: FormGroup, loading, loaded) {
    const response =  control.valueChanges.pipe(
      switchMap((value: any) => {
          return callFrameworkObservable()
      })
    );
    return response;
}

Field Config for `framework`

{
  "code": "framework",
  "visible": true,
  "editable": true,
  "dataType": "text",
  "label": "Course Type",
  "required": true,
  "name": "Framework",
  "inputType": "framework",
  "placeholder": "Select Course Type",
  "output": "identifier",
  "options": getFramework
  "validations": [
    {
        "type": "required",
        "message": "Course Type is required"
    }
  ]
}