如何使用敲除验证

Question

I am following this link to create validations.

But i dont understand how can i use this extend method in my code.

I load data into my observable with records coming from calling breeze query.

I load data in below manner

dataObsArray= ko.observableArray()

datacontext.getData(id,dataObsArray)
                   .then(function () {

          // some logic


 })
        .fail("Data not found");

Then i bind this obs array to my view as below

<tbody data-bind="with: dataObsArraay">
            <tr>
                <td>name</td>
                <td> <input data-bind="  value: Name" ></td>
                <td> <input data-bind="  value: Age" ></td>

            </tr>
</tbody>

So i dont understand how can i use extend method because i am just using binding my view with properties in my observable array.

Please guide me.

Answer 1

Consider using breeze validation instead of putting the validation logic in the UI code via a knockout extender. Using breeze validation will ensure the rules are always evaluated and will save you from creating an extra model over your entity for the purposes of validation.

here's an example using one of breeze's built in validators: the stringLength validator.

var entityType = entityManager.metadataStore.getEntityType('????'),
    nameProperty = entityType.getProperty('Name'),
    nameLengthValidator = breeze.Validator.stringLength({ maxLength: 10, minLength: 2 });
nameProperty.validators.push(nameLengthValidator);

here's an example of a custom required validator for strings that doesn't allow whitespace-only values:

// make a reusable validator
var myRequiredValidator = breeze.Validator.makeRegExpValidator(
    "myRequiredValidator",  
    /\S/,  
    "The %displayName% '%value%' cannot be blank or entirely whitespace");

// register it with the breeze Validator class.
breeze.Validator.register(myRequiredValidator);

// add the validator to the Name property...
var entityType = entityManager.metadataStore.getEntityType('????'),
    nameProperty = entityType.getProperty('Name');
nameProperty.validators.push(nameLengthValidator);

here's the documentation for making regex validators.

You can also write custom validators- check the breeze docs for more info on that- look for the Write a custom validator section.

Answer 2

you'll need to create a model for your data, eg:

function person(name, age) {
    this.name = ko.observable(name).extend({ minLength: 2, maxLength: 10 });
    this.age = ko.observable(age).extend({ min: 18, max: 99 });
}

var data = [],
    people = ko.observableArray();

datacontext.getData(id, data)
    .then(function (data) {
        for (i = 0; i < data.length; i++) {
            people.push(new person(data.Name, data.Age));
        }
    })
    .fail("Data not found");


<tbody data-bind="foreach: people">
    <tr>
        <td>name</td>
        <td> <input data-bind="  value: name" ></td>
        <td> <input data-bind="  value: age" ></td>
    </tr>
</tbody>