Once the form data has been validated on the client-side, it is okay to submit the form. And, since we covered validation in the previous article, we're ready to submit! This article looks at what happens when a user submits a form — where does the data go, and how do we handle it when it gets there?
We also look at some of the security concerns associated with sending form data. The server answers the request using the same protocol. This enables the user to provide information to be delivered in the HTTP request. Note : To get a better idea of how client-server architectures work, read our Server-side website programming first steps module.
The element represents a document section containing interactive controls for submitting information. All of its attributes are designed to let you configure the request to be sent when a user hits a submit button. The two most important attributes are action and method. The action attribute defines where the data gets sent. Its value must be a valid relative or absolute URL.
If this attribute isn't provided, the data will be sent to the URL of the page containing the form — the current page. When specified with no attributes, as below, the element represents a document section containing interactive controls for submitting information.
When you do this, the data is encrypted along with the rest of the request, even if the form itself is hosted on an insecure page accessed using HTTP. On the other hand, if the form is hosted on a secure page but you specify an insecure HTTP URL with the action attribute, all browsers display a security warning to the user each time they try to send data because the data will not be encrypted.
The action value should be a file on the server that can handle the incoming data, including ensuring server-side validation. The server then responds, generally handling the data and loading the URL defined by the action attribute, causing a new page load or a refresh of the existing page, if the action points to the same page. The method attribute defines how data is sent. To understand the difference between those two methods, let's step back and examine how HTTP works.
Each time you want to reach a resource on the Web, the browser sends a request to a URL. An HTTP request consists of two parts: a header that contains a set of global metadata about the browser's capabilities, and a body that can contain information necessary for the server to process the specific request.
The GET method is the method used by the browser to ask the server to send back a given resource: "Hey server, I want to get this resource. Because the body is empty, if a form is sent using this method the data sent to the server is appended to the URL. After the URL web address has ended, we include a question mark?
In this case we are passing two pieces of data to the server:. Note : You can find this example on GitHub — see get-method. The POST method is a little different. It's the method the browser uses to talk to the server when asking for a response that takes into account the data provided in the body of the HTTP request: "Hey server, take a look at this data and send me back an appropriate result.
The Content-Length header indicates the size of the body, and the Content-Type header indicates the type of resource sent to the server.Help to translate the content of this tutorial to your language! We can use both the name or the number in the document to get the form. When we have a form, then any element is available in the named collection form. These navigation properties do not depend on the tag structure.
All control elements, no matter how deep they are in the form, are available in form. They also have elements property that lists form controls inside them. In other words, instead of form.
For any element, the form is available as element. So a form references all elements, and elements reference the form. We can access their value as input.
The first way is the most obvious, but 2 and 3 are usually more convenient. There may be a small confusion about defaultSelected and selected. Usually both values are either set to true or not set same as false. Value is available as input. These are the basics to start working with forms. We want to make this open-source project available for people all around the world. Tutorial map. Working with forms will be much more convenient when we learn them. Navigation: form and elements Document forms are members of the special collection document.
For instance:. Shorter notation: form. Use textarea. It stores only the HTML that was initially on the page, not the current value. Tasks Add an option to select. The solution, step by step:. Previous lesson Next lesson. Comments read this before commenting… If you have suggestions what to improve - please submit a GitHub issue or a pull request instead of commenting.
If you can't understand something in the article — please elaborate.
Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. At some point I need to get all the values in the form on the client side as a collection or a query string. So I'm trying to figure out how to capture all the values in the same type of collection that the form would normally send to the server if the form was actually submitted.
I suspect there is an easy way to capture this, but I'm stumped. The jquery form plugin offers an easy way to iterate over your form elements and put them in a query string. It might also be useful for whatever else you need to do with these values. Thanks Chris. That's what I was looking for. However, note that the method is serialize. And there is another method serializeArray that looks very useful that I may use.
Here is an example. You can also get each field of the form and get its value using the document. Depending on the type of input types you're using on your form, you should be able to grab them using standard jQuery expressions. Learn more. How can I get all a form's values that would be submitted without submitting [duplicate] Ask Question. Asked 11 years, 1 month ago.
Active 3 years, 7 months ago. Viewed k times. Howard Pinsley Howard Pinsley 10k 15 15 gold badges 45 45 silver badges 63 63 bronze badges. Active Oldest Votes. Chris Farmer Chris Farmer The problem with this, is that when using checkboxes, the data doesn't show up at all, I would rather it just be set to false. Bryan Kyle Bryan Kyle DamirOlejar if you are in a submit function evt.
Warning: e. Jun 5 '17 at Just set the value attribute for the checkbox, either directly in the html, or via js. Apoorv Nag Apoorv Nag 4 4 silver badges 8 8 bronze badges.
You can use this simple loop to get all the element names and their values. Jake 2, 1 1 gold badge 23 23 silver badges 30 30 bronze badges. Does this work correctly for checkboxes, radio buttons and multi-selects? The only one I'm not really sure is Listbox, because it has a child collection with Option elements.This article explores such approaches. With progressive web apps, single page apps, and framework based apps, it's common to use HTML forms to send data without loading a new document when response data is received.
Let's first talk about why this requires a different approach. Standard HTML form submission, as described in the previous article, loads the URL where the data was sent, which means the browser window navigates with a full page load. Avoiding a full page load can provide a smoother experience by avoiding network lag, and possible visual issues like flickering. When the user tries to send the data, the application takes control and transmits the data asynchronously in the background, updating only the parts of the UI that require changes.
Most of the XHR code you'll see in this article could be swapped out for Fetch. But if you want to use a third party service, you need to send the data in the format the services require. There are 3 ways to send form data, from legacy techniques to the newer FormData object.
Let's look at them in detail. Note: This use of XMLHttpRequest is subject to the same-origin policy if you want to send data to a third party web site. Building an HTTP request by hand can be overwhelming. The FormData object can be used to build form data for transmission, or to get the data within a form element to manage how it's sent.
Note that FormData objects are "write only", which means you can change them, but not retrieve their contents. Using this object is detailed in Using FormData Objectsbut here are two examples:. You can also bind a FormData object to an element represents a document section containing interactive controls for submitting information.
This creates a FormData object that represents the data contained in the form. You can even get more involved with the process by using the form's elements property to get a list of all of the data elements in the form and manually manage them one at a time.
But to send binary data by hand, there's extra work to do. Unfortunately, some legacy browsers can't access binary data or require complicated workarounds. The least complicated way of sending binary data is by using FormData 's append method, demonstrated above.
It only takes a minute to sign up. I'm sending data from a form with a variable number of fields via an Ajax call. Some of the fields are grouped together so I have opted to send them as an array of JSON objects to keep the groupings, but there are a number of ways of doing this.
Form properties and methods
This seems to work but there are issues with using JSON. I don't know if modifying the form is very efficient either. How would you manage this?
First of all, I'd make sure that supporting IE7 is actually required. It's a really old browser by now, and there are a lot of things that are much more difficult to do. Anyway, as for sending multiple form values, there's a common - but informal - way of doing that without JSON.
Typically - again, this isn't a true standard, just an informal one - you would use a name like foo[bar] to specify that bar is a named sub-property of foo. Or you'd use the name foo multiple times to indicate that foo is an array but this only works for plain value arrays.
Here, you need a little of both, something like this I've skipped a lot of HTML just to make it clearer :. Again, I can't guarantee that how your server will understand it, but it's a common way to do things. Even if your server-side code doesn't understand it automagically, it's still parseable; you just have to write a bit more code yourself. The trick is of course to increment the number, when you add new fields.
Load the page, then type something into the text box. Click the button, and what you typed is shown in the alert box. Here's how the script works.
Both actions lead to submit event on the form. The handler can check the data, and if there are errors, show them and call event.
Both actions show alert and the form is not sent anywhere due to return false :. Then the submit event is not generated. It is assumed that if the programmer calls form. Open a sandbox for the task. Open the solution in a sandbox. We want to make this open-source project available for people all around the world.
Tutorial map. The second — press Enter on an input field. In the form below: Go into the text field and press Enter. Relation between submit and click. Tasks Modal form. A user should type something into a text field and press Enter or the OK button, then callback value is called with the value they entered.
In both cases that ends the input process and removes the form. Requirements: The form should be in the center of the window. The form is modal. In other words, no interaction with the rest of the page is possible until the user closes it.
Previous lesson Next lesson. Comments read this before commenting… If you have suggestions what to improve - please submit a GitHub issue or a pull request instead of commenting. If you can't understand something in the article — please elaborate. Chapter Forms, controls. Lesson navigation Event: submit Method: submit.