Complex questions in expressions

Example of using complex questions values in an expression 

                        

    
        Survey.StylesManager.applyTheme("default");
    


var json = { showQuestionNumbers:  "off",
  questions: [
    {
      type: "matrix",
      name: "matrix",
      title: "Please select the question you wish to answer",
      columns: [
        {
          value: 'yes',
          text: "Yes, I do"
        },
        {
          value: 'no',
          text: "Please do not ask this question"
        }
      ],
      rows: [
        {
          value: "name",
          text: "Could you answer what is your name?"
        },
        {
          value: "city",
          text: "Could you tell us the city you have born?"
        }
      ]
    },
    {
      type: "text",
      name: "name",
      title: "What is your name?",
      visibleIf: "{matrix.name} = 'yes'"
    },
    {
      type: "text",
      name: "city",
      title: "What is the city you have born?",
      visibleIf: "{matrix.city} = 'yes'"
    }
  ]
};

window.survey = new Survey.Model(json);


    survey.onComplete.add(function(result) {
        document.querySelector('#surveyResult').textContent =
            "Result JSON:\n" + JSON.stringify(result.data, null, 3);
    });


survey.render("surveyElement");

;
                    
<!DOCTYPE html>
<html>
<head>
    <title>Example of using complex questions values in an expression, Knockoutjs Survey Library Example</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.4.0/knockout-min.js"></script>
<script src="https://surveyjs.azureedge.net/1.0.92/survey.ko.js"></script>
<link href="https://surveyjs.azureedge.net/1.0.92/survey.css" type="text/css" rel="stylesheet" />
    <link rel="stylesheet" href="./index.css">

</head>
<body>
                <div id="surveyElement">
            </div>
    <div id="surveyResult"></div>

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

</body>
</html>

You may use the typical question value, for example "text", in an expression as: 

visibileIf: "{textQuestion} = 'Yes'"
For questions like Multiple Text, Matrix, Matrix Dropdown, Matrix Dynamic and Panel Dynamic you can't use the same approach.

Multiple Text, Matrix questions values are objects: 
"name": { "firstName": "John", "lastName": "Snow"}
As result you may use it in expression as: 
visibleIf: "{name.firstName} = 'John' and {name.lastName = 'Snow'}"


Matrix dropdown question is an object of objects: 
"rateTeaches": { "math": { "knowSubject": 5, "explainsClearly": 4}, "literature": { "knowSubject": 4, "explainsClearly": 4} }
You may use it in expression as: 
visibleIf: "{rateTeaches.math.explainsClearly} > 3}"


Matrix and Panel Dynamic questions are array of objects: 
"rateTeaches": [{"subject": "math", "knowSubject": 5, "explainsClearly": 4}, {"subject": "literature",  "knowSubject": 4, "explainsClearly": 4} ]
The expression can be as: 
visibleIf: "{rateTeaches[0].explainsClearly} > 3}"