CODEWITHSUNDEEP
javascriptc#asp.net
Vivek Nuna
Vivek Nuna

Reputation: 1

How to set javascript variable from a C# variable in asp.net?

How to set a C# variable to JavaScript array variable which is array. Following choices is array variable.m_lines is c# array variable.

<script type="text/javascript">
     $(document).ready(function () {
                 term = term.toLowerCase();
                 var choices = [];
                  choices = '<%= m_lines %>';
                 //var choices = ['aaaab', 'ActionScript', 'AppleScript', 'Asp', 'Assembly', 'BASIC', 'Batch', 'C', 'C++', 'CSS', 'Clojure', 'COBOL', 'ColdFusion', 'Erlang', 'Fortran', 'Groovy', 'Haskell', 'HTML', 'Java', 'JavaScript', 'Lisp', 'Perl', 'PHP', 'PowerShell', 'Python', 'Ruby', 'Scala', 'Scheme', 'SQL', 'TeX', 'XML'];
    });
</script>

My actual requirement is to read a large text file (size approx 3 MB) and assign it to a JavaScript array variable. I'm not able to read file from client side and assign it to JavaScript variable, so reading at server side and trying it to assign to client side variable. each line of file is being used as array item.

Upvotes: 1

Views: 1373

Answers (3)

Jorge Guerrero
Jorge Guerrero

Reputation: 343

Taking the script from your example, this could be:

<script type="text/javascript">
$(document).ready(function () {

    term = term.toLowerCase();
    var choices = [];
    choices = <%= new System.Web.Script.Serialization.JavaScriptSerializer().Serialize(m_lines)  %>;
    //var choices = ['aaaab', 'ActionScript', 'AppleScript', 'Asp', 'Assembly', 'BASIC', 'Batch', 'C', 'C++', 'CSS', 'Clojure', 'COBOL', 'ColdFusion', 'Erlang', 'Fortran', 'Groovy', 'Haskell', 'HTML', 'Java', 'JavaScript', 'Lisp', 'Perl', 'PHP', 'PowerShell', 'Python', 'Ruby', 'Scala', 'Scheme', 'SQL', 'TeX', 'XML'];
});

Or if this is a comma separated text file and is on the client side, you could read it using javascript, something like:

// <input name="myfile" id="myfile" type="file" />
$("#myfile").on('change', function () {

    var file = this.files[0];
    // Some validations
    console.log(file.name);
    console.log(file.size)

    var FileReader = new window.FileReader();
    reader.onload = function (event) {
        // The file's text will be in event.target.result
        //console.log(event.target.result)
        var fileContentArray = event.target.result.split(/\r\n|\r|\n/g); // split by newlines

        // Use the file content in fileContentArray
    };

    reader.readAsText(file);
});

See: https://developer.mozilla.org/en-US/docs/Web/API/FileReader

Upvotes: 0

David
David

Reputation: 218818

In a comment on the question, you define m_lines as an array. One approach here could be to simply serialize that array to JSON:

choices = <%= JsonConvert.SerializeObject(m_lines) %>;

This is of course using the Newtonsoft JSON.NET library. You might also be able to use JavaScriptSerializer (in System.Web.Script.Serialization) otherwise.

Upvotes: 1

Ravi Shankar
Ravi Shankar

Reputation: 86

Try this - 

var choices = <% if (m_lines!= null) {Response.Write(m_lines.ToString());}%>

Upvotes: 1

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