Passing Data From Initial XML Request To Subsequent Pages - php

`I am working with an API that sends back an XML response upon request. Here's a simplified example:
<buildings>
<building attr1="foo" attr2="bar">
<uri>http://blah.com</uri>
<thumbnail>http://blah.com/foo-picture.jpg</thumbnail>
</building>
<building attr1="poo" attr2="pee">
...
</building>
</buildings>
After I use $.get() to request the XML, I have to search through it to get the <building>s that have attr1="foo" for example.
After displaying this result set, each <building> has a link that sends the user to another page, let's say details.htm?id=fun There is only one 'page,' but the content changes depending on the id that is passed along in the URL.
Finally, the question:
I have to include Next and Previous links to navigate within the result set that I ended up with after searching through the original XML response.
If the result set was always guaranteed to be very small, I could pass it in the url, similar to
details.htm?id=fun&nextid=morefun&previd=lessfun
However, I have to account for the possibility of a very large result set.
Can anyone suggest a method for making the result set persistent while a user is navigating within it? The way I have it set up at the moment is that an array of result IDs is generated after the search is complete and the result set has been returned. Is there a way to make this array portable and (relatively) permanent?

Probably the easiest is to use PHP Sessions unless you want to make a pure ajax site.

Related

Process GET request, but remove query string

I've got some PHP which handles a GET request via a query string. Once processing on that query string is done, it generates a page with the results.
So far so good. But the url in the browser keeps the query string, so e.g. if you hit reload, it again tries to process the GET.
So I'd like to generate the page, but return without the query string. I've tried setting the header() to the URL-minus-query, but that redirects (i.e. reloads) the page, rather than returning directly.
I'd think this is a common and easy task, but I can't find a solution...!
In case anyone runs across this post...
For the general case, given the difficulty of changing the url server-side, it's easiest to go through the effort to make it a POST, or use AJAX.
update: But in my case, it's a page where the user can change account information, which then needed to be reflected on that page. The answer in this case is simple: do the database updates first, then just redirect to the same page: parse_url($_SERVER['REQUEST_URI'],PHP_URL_PATH)
Regular PHP processing handles the rest.
The core problem is that you absolutely MUST NOT use GET for processing anything. GET should be safe and refreshing should have no side-effect. Generally the way people solve this is by:
Doing some processing with a POST request
Redirect to a 'results' page.
The most correct redirect status code for this is 303 See Other, but must frameworks will use 302 Found.

Losing Session when get request header is too long

I'm having a problem with my application.
I created a filter panel on which the users can select multiple parameters and then I pass them to a GET request that hits a function inside a controller that returns the results. All this is very basic stuff, I had no problem implementing this. But my application uses uuids and the request URI gets very long. That results to losing my current session, log out current user and Laravel to generate a new session token.
The URI is something like this:
www.domain.com/search?offer_category[]=892b06ac-6552-43ca-9fcd-ba65d4223e7d&offer_category[]=bc66fd8d-1ea9-4968-bee5-8ab9ab665446&offer_category[]=46907770-13d8-4ba1-be33-58f254624860&offer_category[]=6fd45d2b-8dc0-4d8e-a94c-1d3eab86eb0a&offer_type[]=62f23e8b-c22e-43f7-8bf6-8b393e81a1ca&offer_type[]=d33b2a38-50fe-4868-8cfc-9af9ef39d91e&order_by=duration_to&order_dir=asc
Why is this happening? Is there a max header character count for GET request? Can I get through this? I don't want to use a POST request, I don't think it's the right way to do a search.

How to keep track of multiple request data from the same user in PHP sessions?

So the question is a little complicated, let me explain. My page code is running like this:
User enters query in the search field and clicks submit.
1.1 jQuery loads a new body to display progress data.
1.2 jQuery calls process.php via AJAX and supplies query as the argument.
1.3 jQuery starts setInterval periodic update to grab progress data, stored inside $_SESSION['prog'], and displays it.
When process.php finishes, jQuery stops periodic update, displays final information and calls AJAX to clear the $_SESSION['prog'] variable.
At the moment progress data is stored inside one variable, which is fine as far as different users are concerned (because of the different sessions), but if the same user were to make multiple requests at the same time, the $_SESSION['prog'] variable would be cross-overwritten.
So far I have thought of two possiblities to distinguish data for each request from the same user (same session)
Have jQuery generate some random string and send it together with query (and hope to avoid colission, although that would be unlikely)
Make 2 AJAX calls, first one requesting new_request_id, the second one sending query and new_request_id as parameters.
Have AJAX return something from PHP before is finishes(completes).
I need to connect each browser window (each request) with each running process, so I cannot send back new request ID after the request has been submitted, because I wont know which data to pick up with jQuery in the browser window. Btw, I will change $_SESSION['prog'] to $_SESSION[request_id] -> request_id is what I'm looking for.
It (request_id) could be last_insert_id(), because im creating new DB entries for each valid query, but I don't know how to get it back to each different user window.
I need advice here. Only just begun to code in PHP, AJAX and jQuery, don't really know much about sessions. How should I solve this problem?
Sorry for the lack of code, I will paste is at request.
You could add a unique ID to each request in addition to the session ID. eg. uniqid() in javascript/jquery?
You need to differentiate them somehow. For example use a unique ID autonumber field. MySQL has last_insert_id() which is very useful and handles concurrent requests correctly.
Avoid using Session variables in Ajax requests. Send them with GET (or POST) instead. Even if calling Session_start(); in the Ajax request and getting $_SESSION['prog'] from there, results can be unexpected.

Is there a way to return ajax POST results in pieces / increments?

Is there a way to pass results generated within a PHP page (called into action by an ajax post request) back to the document in bits / intervals?
Here is an example...
I am making an ajax POST to a PHP document with keywords passed by the user which scans a few sites to determine if they have resources for the search. If they do the PHP file returns a link to the site, and continues to the next one, if not I will just continue on to the next one..
with an ajax (I use jQuery) I can make this request and wait for the page to load, and then show all the links together easilly, but am wondering if I can display the links one by one as they load from the PHP file so that I don't have to wait for every page to be checked.
Thank you for your input.
You can implement this by having the client send a request for the first X (5 or whatever) results, display those, and then immediately send the request for the next X records. Your client will simply continue making requests and displaying records until it gets an empty response, at which point retrieval is complete.
To make this work you either need to maintain state on the server so that you know "where" in the search to pick up searching, or the client needs to include sufficient information in each AJAX request for the server to know how to continue processing.
By the way, this seems more like a GET operation than a POST.

Will bad things happen if I control the content of $_POST?

In my days of writing web applications, I'm missing a simple way for a PHP script to direct to another PHP script while passing along data without using the URL
Browsers can pass data invisibly to a PHP script using the $_POST array. So I'm devising a script that will dump the contents of $_SESSION["POST"] into the $_POST array to mimic the passing of post data, then clears $_SESSION["POST"].
For instance, a page X contains a login form. Page X directs to page Y to validate the data. Page Y discovers that the login information is incorrect, and redirects back to page X - which now displays the error message "Login information incorrect" from $_POST.
Am I crazy for missing this feature? Is there some other method of doing this easily that I'm missing?
Please respond with anything that can be helpful.
You could use the session. On page X, you'd put the data into the session. On page Y, you'd validate the data and handle the redirect. You can put your error message into the session too.
The session persists between requests, so it's the perfect place to store that kind of data.
EDIT
OK, I'd do things with session variables, but if you want to avoid that you do have a few other options I can think of besides posting:
You can use files on the server (such as temporary files). Use the user's session key to identify which file is theirs, and you can read and write whatever data you care to it.
You can put the data in a database. That would work too.
Of course neither of those is a true post. If you want a true post, you have another two options.
First, you can return the data to the page in a hidden form, and use JavaScript to trigger a POST. This is simple to do, but it requires the data to pass through the browser. This means you'd have to take care that a user didn't change the data, and the user would have to have JavaScript on. You can checksum the data to ensure it isn't modified, but the JavaScript problem is unsolvable.
Another way to do it would be to take the user out of the equation entirely. When the user submits to page A, page A could make a POST to page B, check the response, and then redirect the user to the proper place. This would be just like if you had to make a JSON or SOAP call to a 3rd party service, except you control that service. It's been a little while, but I believe that HttpRequest is the class to use to do this.
It would be ideal if that URL you check with returns a simple answer ("true", "false", "yes", "no", "good", "bad", whatever), but as long as you can tell by the response whether they were successful or not, you can do it.
Now I should note that I'd agree with mvds, this sounds like a function that should be included in page A so that it can do all the work but the code can be shared with other pages. Having page A post to page B and then redirect to A or C seems unnecessarily complex. Page A can easily accomplish all this. I read your comment on his answer, but it seems there should be another way to accomplish this.
Abstract the performed actions to functions and/or classes, and the need for such kludges will vanish. Concrete: both page X and Y could call the same function to validate the posted login data.
Page X redirecting to page Y to do validation means handing back control to the client, while you could (and should) validate the data right away.

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