Effort
I've read this question, but I still think there has to be a way to do this client side.
Case
I'm submitting a form that has a few inputs. When the form is submitted, the primary key of those inputs is shown on a results page along w/ other data and a different form.
The effect I'm trying to do is if the input-pk is modified, I want it to reload the page (think window.location.reload()), only I want to update that PK parameter's value with the changed value.
window.location.reload takes one of two values (true/false), which distinguishes if it should use browser cache or not. Thus, it seems like it should be accessible, especially since the Firebug::Net plugin shows the param in the HTTP Header.
The form requires 'Post' submissions, which adds a little more complexity.
Alternative
The other thing I've considered is to store the values in a cookie right before submission, which I can retrieve on the next page and then submit another Post; however I'd like to refrain from exposing the data in Cookies.
AFAIK, Javascript does not have access to the POST body. Can't think of an API call for that! If you are using php/.net/ruby, you can encode the POST body as JSON that your JS can use when it's reloaded, can't you?
Related
I need to send form data to another page that will allow the user to do something in a form and return the result of that form back to the original page? Is this possible? I know it's not ideal, but the issue is that I need to make a "drop-in" solution that does not need to be integrated with other code. I know it's a very specific request and scenario.
I know how to send POST data that doesn't require any user input on the processing page. i.e. I can send POST data to 'calculate.php' which will do the math and send it back, but if I need additional user input on 'calculate.php', how can I still send it back?
An example of expected results would be:
Page #1: User enters a number and presses submit to go to next page.
Page #2: User enters a second number and presses submit to finish.
Back to Page #1: User receives sum of both numbers.
Obviously, this is a really redundant thing to do, but I'm trying to simplify the problem as much as possible.
EDIT: There a few restrictions I forgot to add.
Page #1 is not my application, I am developing Page #2 as a "drop-in" solution for Page #1. Essentially, I can only use Page #1 to call Page #2 and receive a response from it. The problem is that I need to be able to allow for user input on Page #2.
I know I can post to Page #2 and then post to Page #1 again, but what if I need to maintain the state of Page #1. For example, if there's an open Web Socket connection.
Please note, I understand that this may be impossible or extremely difficult, but if I don't ask I'll never know right?
You want it with PHP or any other language. If you are running Php on server side then you can use Global variables like $_GET and $_POST.
Page #1: Use Post/Get method to send data to second page.
Page #2: Receive all fields' values using Globe variables ($_GET and $_POST). You can use these values as default values of form fields. Now submit this data to page 1 using post or get method.
Back to Page #1: Here you will receive the data of first page from second page and newly posted data from page 2
Either of these should work:
Never leave the page - use AJAX / XMLHttpRequest to call out to other pages to process chunks of data
Do everything on page 1 using "postbacks" -- the form targets are the same page, there is a state variable like "stage=1", and you use JavaScript to add set hidden variables for any additional state that's needed.
... PHP state validation and processing for the different stages ...
... one or more blocks of HTML for the page (PHP if / else can be used to choose between multiple page views) ...
Edit for added restrictions:
Have page 2 use postbacks or AJAX to collect the additional information
I figured out a few ways to do it.
Update a Database (or Data Store of some sort, depends on security needs) and have Page #1 listen for events from a separate page (on the same server as the database). Very similar to the way PayPal's Instant Payment Notification (IPN) works. I was actually able to set up server sent events with it as well.
Essentially, Page #1 sends data to Page #2 where the user will perform the function and then Page #2 will send POST data to a listener somewhere (either on the same server or Page #1's server), the listener will update a database and Page #1 will be listening or pulling to an event handler that will send an update once the database updates.
Use JavaScript Child/Parent Window functions. This is okay if Page #1 and Page #2 are on the same server, but can get messy and browsers have a lot of restrictions and it varies depending on browser.
Page #1 will open Page #2 in a child window, after the user performs a function, Page #2 will call a function that accepts the result data on Page #1.
I was looking on how to get values of form data that are passed with POST requests and found this answer.
I know you you can get GET query parameters quite easily in JavaScript doing window.location.search but is there a way to do similar for POST request or document.forms is my only option?
To expand on what RUJordan said:
When you do a POST, the information is sent to the server using an entirely different method and does not show up in the URL or anywhere else that JavaScript can get access to it.
The server, and only the server, can see it.
Now, it is possible to take some of the form data and fill JavaScript variables and/or hidden form fields so the server can pass data back down to the client.
If you need more help, you'd be better off opening another question explaining exactly what problem you are trying to solve.
Do you want javascript to see the data was POSTed to load the current page?
JavaScript does not have access to the request body (where the POST content is) that loaded the page. If you want to be able to interact with the POSTed parameters, the server that received the request would need to respond with the necessary data written back out on the page where javascript can find it. This would be done after the form was submitted, as part of the response to that POST request.
Or do you want to know what your page could POST form the forms that are on it?
Inspecting document.forms will let you see what could be POSTed later if those forms were submitted. This would be done before the form was submitted, without a request being made.
*EDIT*
I've done more research and it looks like cookies may also be the answer. I suppose I would add a button to the form inside the embedded html that calls a function to create a cookie for the values. Then I could access this cookie through obj-c using the stringByEvaluatingJavaScriptFromString method. Of course then you run into the issue of expiration, multiple copies of the form not being allowed, etc. So it is a trade-off of features. I'm going to stick with the window.location route because I can store this in a DB and then the user can create another instance of the same form
*EDIT*
I've done some research and I have a vague idea how to accomplish this, but I was curious if there was a better method.
I have a local copy of an html form loading in a UIWebView on this iPad app I am developing. The forms are submitted server-side through xml and parsed there for DB storage, but unfortunately they are pretty lengthy. So I want to let the user save the form in its current state (maybe they only fill it out halfway), and then return to it later.
What I am thinking is that I will have to write some javascript to parse the radio buttons and checkboxes in the form, then pass this data through the window.location trick to the obj-c code. But this is VERY lengthy, and the strings being passed back and forth between JS and Obj-C will be very long. Is there any other way to grab the values of these checkboxes/radio buttons and pass them to the obj-c side to be repopulated later?
How about going via a file? Save the settings/data to a file in JS and access that file in Objective-C land. But I guess you've already thought of this.
But at the end of the day the data has to be passed back and forth regardless of how you do it. Doing it via the window.location trick will be the fastest, and provided there are no limitations imposed by the OS itself is there any reason not to do it this way?
You could encode the data into a blob to make it easier to pass around.
But on the other hand doing it by file route may however be useful if you want the settings to persist if your app gets terminated.
Also you could actually submit the form data but intercept it in Objective-C before it gets sent by using a NSURLProtocol derived class. THe NSURLProtocol class could allow the submission to proceed if it knows the data is complete. But I don't see any point in doing this if window.location doesn't have a size limit.
I want to make the results of an ASP.NET form POST "bookmarkable", and I'm thinking of using query parameters to accomplish this.
The idea is that a user will visit http://domath.com and they will type in a math problem, and view the results. The query and results are visible at http://domath.com?ProblemID={some guid here}
The only part I don't really know is how do I change the target of the form URL since I'm using a POST instead of a GET..
Here are the options I came up with, and I'm not sure what is practical
Submit form as usual, server redirects to a URL with the new parameters attached
Use a webservice or callback to get new URL. Javascript then updates form target
The first option is the easiest and most common. It follows the Post/Redirect/Get model, which avoids double form submission in addition to letting you bookmark the resulting page.
iIhave value in hdnField in form1.aspx . I assign a value to hdnfield in javascript .I want to get that value in aspx.vb in another form, form2.aspx. How can I accomplish this?
If your Form1.aspx submits to Form2.aspx, then you have atleast a few ways to access the value of form fields (including Hidden fields):
The Request.Form property exposes a NameValueCollection containing all submitted form field names as Keys and their values as Values. You could use the syntax Request.Form["fieldName"] to access the value.
If this is ASP.NET 2+ and you used the Cross-page posting technique, you will be able to access field values in the previous page using the PreviousPage property of the Page.
If you use Server.Transfer, you can access values using the Current HttpContext.
If you need more info, you should take a look at Passing values between pages in ASP.NET.
I think your concept of session is wrong. Session is a server-side object, and javascript runs on the client, so you can not directly assign that value to a session. You can, instead, use some AJAX to send it to the server and then add code in the server so the value is assigned.
Hm... you have to think about the difference between serverside and clientside first...
You cant directly access changes you made in the client on the serverside, because you once send a request to server, as a response you get the site diplayed in your browser. As soon as you recieve the request, the server is finished and cant access the site anymore. Its like a letter you send away. As soon as you put it into the mailbox, you cant make changes anymore.
But you could post a new request to the server and add POST or GET peremeters. These can be accessed by the server. The way you send the request doesnt matter... you can send a request using AJAX or simply reload the page.