I want to create a page with will be filled with dynamic info using Ajax (JQuery). The info will come from various GETs I need to do in other URLs.
I'll be using Sinatra + JQuery to to that, but as my WEB experience is almost null and don't have any idea how do to it right.
The requisites for this are:
Each time a GET completes, a new line of information should appear on the page.
If the GET could not be complete, a default info appear on the page.
My idea so far is to do something like this:
Have my controller performing each GET inside a thread.
Each time a thread ends, with success or not, I inform the view of the result and render a partial
I'll have as many partial as I need (for each GET I must do)
The first time I load the page I fill in the default info, them I update via AJAX with the successful GET responses
This does not seem the correct approach, so I'm asking someone that already did something similar or has more experience on this some help.
You start off with a simple get('/'){} route that holds the default message (or any other GET route). Then you have your other GET routes that you want to display on your default route. In Sinatra you can check whether a request is an xhr-request or not with a request.xhr? If you have an xhr request you return a json value to your view, otherwise reject the request or render a view with proper html. This is on your sinatra backend. In your views you can use JQuery or any other JS library or plain JS to handle asynchronous data requests. You can use the ajax function in JQuery to request data from your routes and then add them to your DOM. It's as simple as that :)
Now you will have to investigate on the JQuery site how to make ajax requests and how to append data to existing DOMs. That's all there is to it.
Related
For a website, which doesn't use AJAX I'm using OnDocumentComplete event to know when the page loading is complete.
My question is, how can I detect when website, which uses AJAX requests is ready (e.g. when a website which is fetching some search results by using AJAX finished its work) ?
Ok here is a trick i developed my self.
1-in your html page make a div and set its text to "false".
2-in you server side put a javascript at the end of your returning code. for example your site returns following text upon an ajax call.
a
b
c
d
e
so after this text put a javascript code that will change the text of div from "false" to "true"
so what will happen is that once you receive all the data from ajax call you will also receive the javascript code and that code will run and set the value of div.
so in your page once all data is received you will see the indicator div. and you will know that you have received all data. you can also run functions in similar way upon completion of data.
If I have a controller method that sets flash.success("some.i18n.key"); and I render a page that is loaded via ajax that item does not get removed from flash. Even though I've rendered the content to the screen (html loaded into a div in the success handler of my ajax post) the next page I visit still has the success message in flash. Pages that work with a normal form post,non ajax) this issue does not happen. Any idea whats going on?
Further investigation seems like this might be some sort of race condition. When I do a normal post and the FLASH cookie is returned it expires immediately and on the next request it is not sent back to the server. In the case of the AJAX post and then a subsequent request the cookie IS sent back to the server.
flash values are kept for one redirect. If you call render in your controller at the end of your method, you do not issue a redirect, so values will be available for the next request. To avoid this you have the choice :
use renderArgs in your method to pass your value to the view
at the end of your method, do not call render but call another method of the controller, thus you will issue a redirect instead of a direct render.
Since play 2 they changed the flashing a bit, instead of 2 maps (incoming, outgoing) there is just one.
What I end up doing is calling:
#flash.clear()
Just after the flash messages are rendered (in the view). This way, you are sure they are rendered just once, regardless of weather you use direct render, or redirect.
What is the best way to address an AJAX script that sends data to POST in codeigniter? Right now I am loading a view with the AJAX through $this->load->view('AJAX', $data); however there is no UI or user actions in the view. It's simply running through the script and returning POST data a little after the script loads. I receive the POST data in my model where I input the values into the DB and output some other values based on the data.
I need to open a real view, set metatags and re-direct the user to another website afterwards.
How do I address this?
The problem I'm facing is that I cannot open up another view because the AJAX view is the one that's in focus but I need this AJAX view to be temporary that basically does it's thing and sends to POST.
Is there any convention that I can lookup/research to what I'm describing? Let me know what kind of clarification is needed if any.
Some people like to write "ajax" controllers and post to them exclusively, but you don't need to do that. You can handle the request in the same controller that handles the non-ajax request. Personally, I exclusively return json, but you can return chunks of HTML if that works better for you.
Your exact problem is vague (actual code would help clarify), but I think you are on the wrong track. Don't use a view for processing anything ever. Use your Controller layer, this is for handling input and requests.
Example of controller method responding to either ajax or non-ajax request:
function edit_user()
{
$data['status'] = $this->user_model->save();
if ($this->input->is_ajax_request())
{
// return json string with our update status
// Something like: {"status":true}
echo json_encode($data);
exit;
}
// Load the non ajax view with the same data
$this->load->view('users/edit', $data)
}
$this->input->is_ajax_request() is a function of the Input class that reads $_SERVER['HTTP_X_REQUESTED_WITH'] and checks if it's value is XMLHttpRequest. This should only be true if it's an "ajax" request.
You can make life easier by wrapping this in a class or function. No matter what you decide to do, don't use the view layer for processing data.
I think my problem is, how do I address javascript without a view? how do I call the script and/or where do I put the JS code in the controller? I felt it was the wrong direction to address the code in a view but I didn't see how else to do it.
Whenever possible, you should put javascript code in a .js file and use a <script> tag to load it, in an HTML document. The only other exception is putting it in a "view" file (a file that's only purpose is to construct your final HTML output). In other words, follow the same rules of HTML as to where to put javascript, and follow the usual conventions of MVC of where HTML belongs (in the view). Javascript code does not belong in your controller. Javascript is not processing your data, it is sending the data to the server.
I need to open a real view, set metatags and re-direct the user to another website afterwards.
If you want to load a view, then redirect (after a certain amount of time I assume), you can do it with javascript or a <meta> tag (but don't use a meta tag, use js).
i am using cakephp in my project. in this at one section i need to update the particular row onclick of the image. using ajax. i used mootools as javascript library. so please help me how could i do this.
thanks in advance
Simply speaking:
Create a CakePHP controller action that performs the row update.
Determine the URL of the controller action you just created. (ie. /controllername/actionname)
Determine if you need to do a GET or POST request to this URL for it to work.
Put code in your view that attaches an "onclick" event that makes and AJAX (GET/POST) request to the above controller.
CakePHP has a javascript helper that traditionally produced Prototype code, but in v1.3 it is now able to produce code for other Javascript frameworks (such as Mootools, jQuery, etc.)
However, many suggest writing your javascript in javascript (eg. actually using the Mootools framwork), rather than writing your javascript in PHP (like using CakePHP's helper to produce Mootools code).
Either way, in your view you need to have something like: <?php echo $js->link(.. or <script>Moo.. or <a onclick="Moo.. to attach your Javascript to that link.
You may also wish for your controller action to return some sort of response indicating whether or not the row update failed or succeeded. In that case you need to make sure the CakePHP controller action you are calling has a view that outputs this. JSON seems to be the ideal format for this (eg. { success: true }), but you need to remember to turn off Cake's debug output. This response can be captured into a variable by your Mootools code where you can decide what to do with it (eg. displaying an error).
As i know most programmer work with protype.js library.
i am giving you link see
go to there
When we use AJAX for validation the response comes through xml file and in case of javascript the response comes through html page.
Is it true or false ?
please explian both the cases.
Ajax can return pretty much anything. Your particular application or implementation might be returning XML, but Ajax commonly returns JSON and HTML as well. But it can return TXT or just status codes ..
AJAX is such a broad term that both of your cases can be called like that. Basically every call from already loaded page is AJAX even if it's done by dynamically creating tag or refreshing iframe.
actually Ajax is nothing but a term to describe what is happening, the response comes as an xml or html depending on what you want it to return, it is a string that ajax returns, in Javascript it is up to you what to do with that string, want to parse it as XML node? want to display it immidiately in an element "innerHMTL" or want to alert the returned string... the power of ajax is not what it returns, it is what it does on the server (remotly) without having to send the whole page in.
AJAX there can be any type of return text. With Javascript it can work on the DOM object and get anything from the page.
The main difference, AJAX a request goes to the server and the result is returned.