Lets say there is a url out there e.g. www.website.com/data.jsp
the link has the following JSON data
{"successful":"true","rows":[{"zip":"65472","user_id":"10843","name":"Rufio"}]}
I just want to be able to extract this data at runtime however I am having a hard time getting it using getJSON
$.getJSON("test2.jsp",function(result){
$("div").append(result.rows[0].user_id + " ");
});
Now if I run it using a local file with the data residing in test2.jsp as shown above it appends the user_id. However when I try to access "www.website.com/data.jsp" instead nothing happens. I don't believe the website is configured to work with JSONP either.
I need a way to figure out how to pull this data from the website at run time. Does anyone have any solutions or workarounds?
p.s. Is this something that might need to be sorted out on the other end? The people who own the website set this scenario up to be like a fake api call like typically you would pass in parameters to get back the specific information that you would need. In the case of this endpoint or url it just returns a single record or the file just contains the data listed above. They would like me to extract the data from their url at runtime.
You can't make a normal ajax call to to this other domain due to same origin policy.
You can use JSONP to load the remote page, but looking at that example output you wouldn't be able to access the data unless the remote site is setup for JSONP (assigning the JSON to a variable, calling a callback function, etc).
You could create a server-side passthrough script of your own. You don't mention what server-side technology you have available, but if you can use PHP, you do a passthrough like this:
<?php
echo file_get_contents("http://www.website.com/data.jsp");
?>
PHP (or any other server-side language) can fetch the remote data, and now you can use ajax to call your own script (which works since you're on the same domain).
Related
I'm want to (or think I need to) use AJAX to accomplish what I intend.
When clicking on a specific link in a list of links, I want to fill the HTML markup below with content of specific subpages. The data is naturally somewhere in the database and actually easily accessible with the CMS's API (I'm using Processwire).
I'm quite new to coding and especially AJAX and all documentation I find online only mention it in combination with a JSON file that would be loaded via AJAX.
However, I don't have a JSON file on the server, that means, according to my understanding, I would need to
store the data I need in a multidimensional php array,
use json_decode to create and then save that JSON-file on the server,
load that file via AJAX and process through more JS.
Let alone keep that JSON-file updated (or create a new one and delete the old one?) since new content will arrive periodically. It seems unnecessarily complicated to me, but what do I know.
There's got to be a better way…
Any help is appreciated.
AJAX is simply a way to make a request to the web server for information.
When you make an AJAX request you ask for a response from a file on a server. So, you can send an AJAX request to a PHP script for-instance.
The PHP script could return anything, JSON is common and very widely used response format, but XML might be another one you've encountered.
So, your request for information is made using AJAX, and the response you get back is JSON.
You don't need to store a JSON file on your server. You just need to make an AJAX request that returns current data in JSON format.
AJAX allows you to do asynchronous HTTP requests.
You can of course ask for a json file, but you can also (for example) call an API.
I suggest you start by reading the the getting started guide for AJAX in MDN:
https://developer.mozilla.org/en-US/docs/Web/Guide/AJAX/Getting_Started
I'm executing script on one site. I'd like to pass some params to php on other site (even other domain) and include JS which should be returned from php request. Is it even possible to do?
You can try using JSON,
Complete processing your script on site 1, convert the variables into JSON or simply make a post request to the site on another domain.
Grab the JSON or post Input from site 1 and execute the the php script on site-2, now pack the output into a JSON,(don't forget to serialize/escape the output using htmlspecialchars) all you have to do is json_encode.
Return the output to the post request from site-1.
All of this will work. But here is the catch, you must not pass scripts over the air unless you know your script is safe. They can be intercepted and can be hacked. And the input also must be from trusted sources.
You might also want to check your CORS settings.
I am trying to write my first chrome extension. The workflow goes something like this -When the extension is installed and active if a user hovers over a specific product/ID displayed on the page, the extension retrieves related vendor data about the product with the ID.
This is how I thought about this:
Use jQuery attr to access the ID on mouse over.
Post this ID to a retrieve.php file with .post() method
The retrieve.php file retrieves the data from database
Display the data in a tool tip on the web page.
I have some queries for the above process:
I am able to get this working on a local XAMPP server but how will it work online as the chrome extension will not have access to server. What is the way around to retrieve data without using PHP?
I am able to get the logic working but am unable to place these in respective files - Will all my logic reside in background.js ?
Any suggestions on getting this started will be much appreciated.
You could build a very simple API on your server that responds with JSON to any request it receives after processing it. Like this:
{"firstVar":"foo","secondVar":"bar" }
Your chrome extension can then make an xmlhttp request to this server and and process the returned data.(You could also use JSONP and wrap the response in a callback function which will execute as soon as you have the reponse)
The JS extension will be able to deal with the JSON nicely as it can understand that format so you can then choose to display the data in whatever way you want.
Essentially, what you want is a server that can take an ID posted to it and return the corresponding date in a nice and readable format. And a chrome extension that can make an request to a server and then process the response. Build and test them separately (keep positing an ID to the server and see the response and for your JS side at first instead of making requests to your unfinished API just set a static response to begin with which will be the same as an expected response.
I have been playing around with the jQuery library the last week or two.
Very handy! I am now playing with the AJAX requests to retrieve things such as the weather, current downloads and more, which have been going well so far!
I have now tried to connect up to my ISP to get my current data usage (peak, off peak etc).
When I use Chrome, I can manually type the variables into the URL and have the required JSON code show in the browser. The issue is, that it seems to return text/html instead of application/json.
When you go into developer tools, it shows text/html. This make it difficult for me to retrieve the data from my home server using AJAX and JSONP. See here for a failed query (but you can still see the text/html output, which is in a JSON format! Failed JSON Query on ISP
My question is, how could I get this data from the server URL, then make it into JSON that jQuery can read?
When I try the .load , $.get functions I run into Cross Origin Issues...
EDIT:Here is the PDF documentation for the API (Download at the bottom of the page)
Notice that I need to append certain values (user / pass / token). My ultimate aim is to have my JS read these values and store them.
The issue is, that it seems to return text/html instead of application/json.
That's a serverside issue. Go and file a bug report.
This make it difficult for me to retrieve the data
Not by itself. You should be able to override the settings how responses are parsed, e.g. in jQuery by using the datatype parameter.
using AJAX and JSONP
Notice that you cannot use JSONP, as it is not supported by that API (judging from the docs and a simple ?callback=test try). If you want support for that, file a bug report against the service provider.
When I try the .load, $.get functions I run into Cross Origin Issues...
Yes. They don't send CORS headers either. I suspect that this API is only used internally, and by devices that are not subject to a same-origin policy.
how could I get this data from the server URL, then make it into JSON that jQuery can read?
Use a proxy on your own server (that runs in the same domain as your app). It can also fix that content-type header.
For more details see also Ways to circumvent the same-origin policy, though most of the methods require cooperation of the service provider (to implement serverside features).
If i understand you correctly You ask for a certain value and it gives you a string. For most API's in the world they send a string that you have to parse into JSON or some language code. I would suggest looking at Parsing JSON Strings link. It explains how to take well formated strings and parse them into JSON readable objects.
var obj = jQuery.parseJSON( '{ "name": "John" }' );
alert( obj.name === "John" );
if you go on further and start using php take a look that Parsing JSON Strings with PHP
EDIT:
use .done() method to grab text from other pages after AJAX call.
$.ajax(...).done(function(html){
//do what you want with the html from the other page
var object = $.parseJSON(html)
}
I am developing a web app which functions in a similar way to a search engine (except it's very specific and on a much smaller scale). When the user gives a query, I parse that query, and depending on what it is, proceed to carry out one of the following:
Grab data from an XML file located on another domain (ie: from www.example.com/rss/) which is essentially an RSS feed
Grab the HTML from an external web page, and proceed to parse it to locate text found in a certain div on that page
All the data is plain text, save for a couple of specific queries which will return images. This data will be displayed without requiring a page refresh/redirect.
I understand that there is the same domain policy which prevents me from using Javascript/Ajax to grab this data. An option is to use PHP to do this, but my main concern is the server load.
So my concerns are:
Are there any workarounds to obtain this data client-side instead of server-side?
If there are none, is the optimum solution in my case to: obtain the data via my server, pass it on to the client for parsing (with Javascript/Ajax) and then proceed to display it in the appropriate form?
If the above is my solution, all my server is doing with PHP is obtaining the data from the external domains. In the worst (best?) case scenario, let's say a thousand or so requests are being executed in a minute, is it efficient for my web server to be handling all those requests?
Once I have a clear idea of the flow of events it's much easier to begin.
Thanks.
I just finish a project to do the same request like your req.
My suggestion is:
use to files, [1] for frontend, make ajax call to sen back url; [2] receive ajax call, and get file content from url, then parse xml/html
in that way, it can avoid your php dead in some situation
for php, please look into [DomDocument] class, for parse xml/html, you also need [DOMXPath]
Please read: http://www.php.net/manual/en/class.domdocument.php
No matter what you do, I suggest you always archive the data in you local server.
So, the process become - search your local first, if not exist, then grab from remote also archive for - 24 hrs.
BTW, for your client-side parse idea, I suggest you do so. jQuery can handle both html and xml, for HTML you just need to filter all the js code before parse it.
So the idea become :
ajax call local service
local php grab xm/html (but no parsing)
archive to local
send filter html/xml to frontend, let jQuery to parse it.
HTML is similar to XML. I would suggest grabbing the page as HTML and traversing through it with an XML reader as XML.