Can you nest html forms?

Question

Is it possible to nest html forms like this

<form name="mainForm">
  <form name="subForm">
  </form>
</form>

so that both forms work? My friend is having problems with this, a part of the subForm works, while another part of it does not.

Answer 1

The second form will be ignored, see the snippet from WebKit for example:

bool HTMLParser::formCreateErrorCheck(Token* t, RefPtr<Node>& result)
{
    // Only create a new form if we're not already inside one.
    // This is consistent with other browsers' behavior.
    if (!m_currentFormElement) {
        m_currentFormElement = new HTMLFormElement(formTag, m_document);
        result = m_currentFormElement;
        pCloserCreateErrorCheck(t, result);
    }
    return false;
}

Answer 2

While I don't present a solution to nested forms (it doesn't work reliably), I do present a workaround that works for me:

Usage scenario: A superform allowing to change N items at once. It has a "Submit All" button at the bottom. Each item wants to have its own nested form with a "Submit Item # N" button. But can't...

In this case, one can actually use a single form, and then have the name of the buttons be submit_1..submit_N and submitAll and handle it servers-side, by only looking at params ending in _1 if the name of the button was submit_1.

<form>
    <div id="item1">
        <input type="text" name="foo_1" value="23">
        <input type="submit" name="submit_1" value="Submit Item #1">
    </div>
    <div id="item2">
        <input type="text" name="foo_2" value="33">
        <input type="submit" name="submit_2" value="Submit Item #2">
    </div>
    <input type="submit" name="submitAll" value="Submit All Items">
</form>

Ok, so not much of an invention, but it does the job.

Answer 3

I ran into a similar problem, and I know that is not an answer to the question, but it can be of help to someone with this kind of problem:
if there is need to put the elements of two or more forms in a given sequence, the HTML5 <input> form attribute can be the solution.

From http://www.w3schools.com/tags/att_input_form.asp:

1. The form attribute is new in HTML5.
2. Specifies which <form> element an <input> element belongs to. The value of this attribute must be the id attribute of a <form> element in the same document.

Scenario:

• input_Form1_n1
• input_Form2_n1
• input_Form1_n2
• input_Form2_n2

Implementation:

<form id="Form1" action="Action1.php" method="post"></form>
<form id="Form2" action="Action2.php" method="post"></form>

<input type="text" name="input_Form1_n1" form="Form1" />
<input type="text" name="input_Form2_n1" form="Form2" />
<input type="text" name="input_Form1_n2" form="Form1" />
<input type="text" name="input_Form2_n2" form="Form2" />

<input type="submit" name="button1" value="buttonVal1" form="Form1" />
<input type="submit" name="button2" value="buttonVal2" form="Form2" />

Here you'll find browser's compatibility.

Answer 4

In a word, no. You can have several forms in a page but they should not be nested.

From the html5 working draft:

4.10.3 The form element

Content model:

Flow content, but with no form element descendants.

Answer 5

Today, I also got stuck in same issue, and resolve the issue I have added a user control and
on this control I use this code

<div class="divformTagEx">

</div>

<asp:Literal runat="server" ID="litFormTag" Visible="false">
'<div> <form  style="margin-bottom: 3;" action="http://login.php" method="post" name="testformtag"></form> </div>'</asp:Literal>

and on PreRenderComplete event of the page call this method

private void InitializeJavaScript()
{
        var script = new StringBuilder();
        script.Append("$(document).ready(function () {");
        script.Append("$('.divformTagEx').append( ");
        script.Append(litFormTag.Text);
        script.Append(" )");
        script.Append(" });");
        ScriptManager.RegisterStartupScript(this, GetType(), "nestedFormTagEx", script.ToString(), true);
    }

I believe this will help.

Answer 6

A simple workaround is to use a iframe to hold the "nested" form. Visually the form is nested but on the code side its in a separate html file altogether.