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@karthikraj-duraisamy
Created March 28, 2018 10:31
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This is a sample file for pre populating, reading and validating inside html using javascript
<!DOCTYPE html>
<html>
<body>
<form id="myForm" action="/action_page.php">
First name: <input type="text" name="fname" value="Donald"><br>
Last name: <input type="text" name="lname" value="Duck"><br>
<input type="submit" value="Submit">
</form>
<p>Click the "Try it" button to display the number of elements in the form and print the form values with validation alert.</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
//This is for pre-populating the data in the fields
var formName = "myForm";
var x = document.getElementById(formName).elements.length;
var form = "\nForm values: ";
var element = "";
for(var i = 0; i < x; i++) {
element = document.getElementById(formName).elements[i];
element.value = "Nothing"
if(element.type == "text")
form = form + "" + element.value;
}
//This is for parsing the data from the fields
function myFunction() {
validation();
var formName = "myForm";
var x = document.getElementById(formName).elements.length;
var form = "Form values: ";
var element = "";
for(var i = 0; i < x; i++) {
element = document.getElementById(formName).elements[i];
element.value = "CDF"
if(element.type == "text")
form = form + "<br/>" + element.value;
}
document.getElementById("demo").innerHTML = "Found " + x + " elements in the form. <br/><br/>" + form;
}
//This is for validating the data from the fields
function validation() {
var formName = "myForm";
var x = document.getElementById(formName).elements.length;
var element = "";
for(var i = 0; i < x; i++) {
element = document.getElementById(formName).elements[i];
if(element.type == "text" && element.name == "fname" && element.value.length < 5)
alert("First name should be more than 5 characters");
}
}
</script>
</body>
</html>
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