Example of creating a custom validator using a custom function in expressions, Knockoutjs Survey Library Example

Custom Validators

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            Survey.StylesManager.applyTheme("bootstrap");
            Survey.defaultBootstrapCss.navigationButton = "btn btn-green";
        

function MyTextValidator(params) {
    var value = params[0];
    return value.indexOf("survey");
}
// Register the function for use in SurveyJS expressions
Survey.FunctionFactory.Instance.register("MyTextValidator", MyTextValidator);
            
                var json = {
  "questions": [
    {
      "type": "comment",
      "name": "memo",
      "isRequired": true,
      "title": "Type here 'survey' to pass the validation ",
      "validators": [
        {
          "type": "expression",
          "text": "You text should contains 'survey' word.",
          "expression": "MyTextValidator({memo}) >= 0"
        }
      ]
    }
  ]
};

                window.survey = new Survey.Model(json);
            
        
            survey.onComplete.add(function(sender) {
            document.querySelector('#surveyResult').textContent =
            "Result JSON:\n" + JSON.stringify(sender.data, null, 3);
            });
        
            
                survey.render("surveyElement");

<!DOCTYPE html>
<html lang="en">
<head>
    <title>Example of creating a custom validator using a custom function in expressions, Knockoutjs Survey Library Example</title>

<meta name="viewport" content="width=device-width" />
    <script src="https://unpkg.com/knockout@3.5.1/build/output/knockout-latest.js"></script>
    <script src="/DevBuilds/survey-knockout/survey.ko.min.js"></script>
    <link rel="stylesheet" href="https://unpkg.com/bootstrap@3.3.7/dist/css/bootstrap.min.css">
    <link rel="stylesheet" href="./index.css">

</head>
<body>
    
            <div id="surveyElement" style="display:inline-block;width:100%;">
            </div>
    <div id="surveyResult"></div>

<script type="text/javascript" src="./index.js"></script>

</body>
</html>

Custom Validators

Example of creating a custom validator using a custom function in expressions

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