Develop Reference

How can I transfer the information I get from the form to another page?

How can I show the information I got from the place where I entered the title and text on the announcement page?
repo:https://github.com/qswezy/spa1
We have added the form and we want to show it in the announcements

Forms usually have target page. So, this is the page that will receive your submitted data, usually in some type of POST array (if you submitted it as a post.) If this assumes JavaScript, you probably need to run an Express server to do this.

Remeber file selection

I have a form which asks to select a file for upload. PArt of the form requires the user to click through to another page. This is fine as I can store field values in local storage. The problem is the file selection - is there a way to remember what the user selected once they navigate back to the form?
If not can anyone suggest how to implement what I am trying to do?
Thanks

So as you are not posting some code examples, I assume that your are not interested in code suggestions.
You could use a session to store some data the user gave you over a form. CakePHP comes with the nice session helper, which makes it easy to deal with.
How to use sessions with CakePHP you can find here:
http://book.cakephp.org/3.0/en/development/sessions.html
So everytime the user fills out the form you could store the relevant data inside the session. Inside your view you just check if there is a value for that data in your session. If yes render the session value as default if not you can render the default value.

Return data from SQL based on user input without reloading form - Classic ASP

I am working on adding a new feature to an existing Classic ASP application. In this feature the user will scan a bar-code which will input its value into a text field in a form within a bootstrap modal. The scanner is configured to send a TAB as well after the data.
What I need is a way to query the database on field exit and populate other fields in the modal with data from the query that is based on the scanned value. I need to do this without reloading the page or closing the modal so the user can verify this information and make changes before saving the form.
What is the best way to do this? I have no issue writing the SP, but do not have any idea how to call it and then return it's values. Can I possibly use JavaScript/PHP for this?

You will need to use some ajax
https://learn.jquery.com/ajax/
Basically you would send a request to your .asp script which will run the stored procedure then send a response using Response.Write.
Then parse that response in jquery.
Unlike ASP Classic, AJAX is a new technology so it works better with JSON.
There aren't many JSON libraries
You can use json2.asp:
https://github.com/nagaozen/asp-xtreme-evolution/blob/master/lib/axe/classes/Parsers/json2.asp
Or if you want you can try it XML, but its unpopular these days and more tedious to parse.
You mentionned PHP, that's not a bad idea because, it's all built in for you see:
http://php.net/manual/en/function.json-encode.php
Hope this helps

Is there a way to get the form data easily with JavaScript?

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.

JavaScript: How to read browser's cache of POST data?

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?