Question

This has driven me really bananas. It’s so simple and easy and yet I can’t figure out what’s wrong with it.

I want to get my checkbox value populated in my controller (for testing purposes).

Here is my form.

<a href='#' name='submitForm'>submit the form</a>   
//I have jquery attached to this tag and will submit the form when user clicks it

echo form_open('test/show');

echo form_checkbox('checkbox[]','value1');
echo form_checkbox('checkbox[]','value2');
echo form_checkbox('checkbox[]','value3');
echo form_checkbox('checkbox[]','value4');

echo "<input type='text' name='text1' value='ddd'>";

echo form_close();


//My controller test

public function show(){

$data1=$this->input->post('text1');  
//I can get text1 value from input box

$data2=$this->input->post('checkbox');  
//it keeps giving me undefined index 'checkbox'

$data3=$_POST['checkbox'];
//same error message
//WTH is going on here!!!!!

}

Please help. This thing drives me nuts! Thanks.

UPDATE:
Thanks for the help. To be more precisely, my submit button is a <a> tag and outside of form tag. It appear that I have to include <a> tag inside my form tag to make them works. Is that true?

Answer 1

A checkbox will not submit any data if it is unchecked as they’re not considered successful (as per the w3c specification here)

If you actually tick the box and submit, it’ll work – in fact it does, I’ve just tested it.

You need to wrap calls to $_POST in the isset() function.

if( isset( $_POST['checkbox'] ) ) {}

Calling $this->input->post('checkbox') shouldn’t give you an undefined index error as the method deals with this eventuality. the Input::post() method returns false or the value of the checkbox.

Edit —

In response to your amendment to your question, you must use an element of type input with the type attribute set to submit in order to submit your form data without the use of Javascript etc. This button must be INSIDE the <form></form> which you are intending to submit.

<input type="submit" value="Submit">

The type="submit" causes the browser to send the data as submit event occurs. If you wish to use another element insider or outside of the form to do this you need to use Javascript. This however can be disabled on a per browser/user basis and isn’t reliable as a result.

// Standard Javascript
<form name="myform"...
<a onclick="javascript:document.myform.submit();" href="javascript:void(0)">Submit</a>

// jQuery
$('#my-a-tag-submit-button').live( 'click', function() {
    $('#my-form').submit();
}