Develop Reference

PHP $_GET and underlines

I have a very short piece of PHP that I use to make HTTP requests from JavaScript.
<?php echo file_get_contents($_GET['url']); ?>
I have used it successfully in a few projects, but am running into a problem with making requests in my current project. Based on my searching, I believe it may be caused by the underscore in the request, though through my searching and not knowing PHP, I have not been able to confirm that.
Below is an example of what I am doing from JavaScript:
$.get("grabber.php?url=" + "http://tidesandcurrents.noaa.gov/api/datagetter?station=8573364&begin_date=20160202&end_date=20160203&product=predictions&units=english&time_zone=gmt&format=json&application=poseidonweathercom+&datum=MLLW", function(forecast) {
console.log(forecast);
});
If I copy the url and put in it in a browser, I get back the JSON that I requested. When I use the code above, I end up getting an error message from NOAA:
Wrong Product : Product cannot be null or empty Wrong Time zone: Time zone cannot be null or empty Wrong Unit:Unit cannot be null or empty Wrong Format: Format cannot be null or empty Wrong Date: The beginDate cannot be null or empty
Do I need to use a regex for the underscore in PHP? Is there some other issue that I do not understand?
Thanks.

You need to send it encoded, which will convert all the underscores/spaces/ampersands etc. with their encoded equivalents:
var url = "http://tidesandcurrents.noaa.gov/api/datagetter?station=8573364&begin_date=20160202&end_date=20160203&product=predictions&units=english&time_zone=gmt&format=json&application=poseidonweathercom+&datum=MLLW";
$.get("grabber.php?url=" + encodeURIComponent(url), function(forecast){
console.log(forecast);
}
Using encodeURIComponent() on that URL shows:
http%3A%2F%2Ftidesandcurrents.noaa.gov%2Fapi%2Fdatagetter%3Fstation%3D8573364%26begin_date%3D20160202%26end_date%3D20160203%26product%3Dpredictions%26units%3Denglish%26time_zone%3Dgmt%26format%3Djson%26application%3Dposeidonweathercom%2B%26datum%3DMLLW
Alternatively, if you just want to access the JSON data and handle it within the JavaScript function, you can retrieve the data via the URL directly, without having to encode the URL:
$.get("http://tidesandcurrents.noaa.gov/api/datagetter?station=8573364&begin_date=20160202&end_date=20160203&product=predictions&units=english&time_zone=gmt&format=json&application=poseidonweathercom+&datum=MLLW", function(forecast) {
console.log(forecast);
});

Um why do you even need your php code ... the code below will work just fine and eliminate your server overhead.
$.get("http://tidesandcurrents.noaa.gov/api/datagetter?station=8573364&begin_date=20160202&end_date=20160203&product=predictions&units=english&time_zone=gmt&format=json&application=poseidonweathercom+&datum=MLLW", function(forecast) {
console.log(forecast);
});

save parsed JSON as obj

first question ever, I'm trying to parse a JSON file stored within the same file directory on my webhost as my html file that runs the javascript to parse it, I've added a console.log to debug and confrim that the file is being caught by the 'get' to ensure that I am able to 'get' the file throgh the use of jquery getJSON, in the callback i've tried to create a function that re-defines a global variable as an object containing the parsed data, but when I try to inject it into a document.getElemendtById('example').innerhtml = tgmindex.ToughGuys[1].name;
it returns a error "Uncaught TypeError: Cannot read property '1' of undefined"
here's my js/jquery
var tgmIndex;
$(document).ready(function () {
$.getJSON("http://webspace.ocad.ca/~wk12ml/test.json",function(data){
console.log( "success" );
tgmIndex =$.parseJSON;
document.getElementById('tgm1').innerHTML= tgmIndex.ToughGuys[1].name;
});
});
and here is whats contained in the JSON (i made sure to try linting it first and it's a valid json)
{"ToughGuys":[
{"name":"Ivan", "position":"Executive"},
{"name":"Little Johnny", "position":"Intern"},
{"name":"Beige Cathy", "position":"Executive"},
{"name":"Stan", "position":" original Intern"}
]}

You're setting tgmIndex to the parseJson function.
Should be doing tgmIndex =$.parseJSON(data);

Presumably your service is returning application/json. Therefore data already contains the json.
tgmIndex = data;
Then... "Tough Guys" is what you should be indexing. Not "ToughGuys"
Your example JSON is wrong in your question. If I go to
http://webspace.ocad.ca/~wk12ml/test.json
I see:
{"Tough Guys":[
{"name":"Ivan", "position":"Executive"},
{"name":"Little Johnny", "position":"Intern"},
{"name":"Beige Cathy", "position":"Executive"},
{"name":"Stan", "position":"Intern 0"}
]}
See "Tough Guys" There's your problem.
document.getElementById('tgm1').innerHTML= tgmIndex['Tough Guys'][1].name;
If data for some reason isn't JSON:
tgmIndex = $.parseJSON(data);

Why jQuery.parseJSON does not parse this valid JSON document in Firefox?

Server returns this JSON document:
{
"username-found": true,
"question-required": true
}
Which successfully passes JSONLint's validity check.
In web browser:
$.post('my_url', {"post":"data"}, function(data) {
data = $.parseJSON(data);
});
The code runs and successfully parses the JSON document in Opera 12 browser, however in Firefox 16, JavaScript error occurs and says "not well-formed".
JQuery is of version 1.7.2.
I cannot see what I did wrong there, do you know?
Edit:
Does it have anything to do with the way server returns the JSON? Here it is:
return new StreamingResolution("text", new StringReader(json.toString()));
uggestion, I might have found the cause. When I did alert(data), Firefox tells me that data is an object, Opera tells me that data is the JSON string.

Solution 1 (Client) - Set DataType in jQuery Request
I think the internals are a bit different in that specific browser version (because jQuery tries to detect the dataType automatically and is doing the parsing internally in the case of a JSON response) and JSON is automatically encoded in FF and not in Opera?
Try to add the dataType so jQuery will handle this (I would prefer that):
$.post('my_url', {"post":"data"}, function(data) {
// data should be an json object here
}, 'json');
It's just a guess.
OR Solution 2 (Server) - Send MIME type
You could also send a correct MIME type from the server so you don't have to set the dataType on the client. Its up to you but I think that would be the correct solution.
Regarding this answer it should be application/json.
Reference
How is the dataType detected automatically in jQuery?
Default: Intelligent Guess (xml, json, script, or html) The type of
data that you're expecting back from the server. If none is specified,
jQuery will try to infer it based on the MIME type of the response (an
XML MIME type will yield XML, in 1.4 JSON will yield a JavaScript
object, in 1.4 script will execute the script, and anything else will
be returned as a string).
Source: http://api.jquery.com/jQuery.ajax/

You can directly use the data object directly ..
No need to use $.parseJSON();

You also have a $.getJSON shortcut method in jQuery. Maybe jQuery automatically uses the best configuration for this case and maybe start working
Here is the $.getJSON documentation

AJAX responseXML

i have a problem regarding the responseXML of ajax..
I have this code from my callback function:
var lineString = responseXML.getElementsByTagName('linestring')[0].firstChild.nodeValue;
However, the linestring can only hold up to 4096 characters max.. the remaining characters are rejected.
I dont know what to use to get all the values that the lineString
returns. its quite a big data thats why I thought of using the responseXml
of AJAX, BUT turned out it still cannot accomodate everything.
My linestring consists of lines from a logfile which I concatenated and just
put line separator. I need to get this data in my form so that is why after reading from the php, i send it back via AJAX
Do you have suggestions guys.

XML adds a lot of extra markup for most ajax requests. If you are expecting some kind of list with data entities, sending them in a JSON format is the way to go.
I used JSON to get quite huge arrays with data.
First of all, JSON is just Javascript Object Notation meaning that the Ajax Request would request a String which will actually be evaluated as a Javascript object.
Some browsers offer support for JSON parsing out of the box. Other need a little help. I've used this little library to parse the responseText in all webapps that I developed and had no problems with it.
Now that you know what JSON is and how to use it, here's how the PHP code would look like.
$response = [
"success" => true, // I like to send a boolean value to indicate if the request
// was valid and ok or if there was any problem.
"records" => [
$dataEntity1, $dataEntit2 //....
]
];
echo json_enconde($response );
Try it and see what it echos. I used the php 5.4 array declaration syntax because it's cool! :)
When requesting the data via Ajax you would do:
var response
,xhr = getAjaxObject(); // XMLHttp or ActiveX or whatever.
xhr.open("POST","your url goes here");
xhr.onreadystatechange=function() {
if (xhr.readyState==4 && xhr.status==200) {
try {
response = JSON.parse(xhr.responseText);
} catch (err) {
response = {
success : false,
//other error data
};
}
if(response.success) {
//your data should be in response
// response.records should have the dataEntities
console.debug(response.records);
}
}
}
Recap:
JSON parsing needs a little help via JSON2 library
PHP can send maps as JSON
Success boolean is widely used as a "successful/unsuccessful" flag
Also, if you're into jQuery, you can just set the dataType : "json" property in the $.ajax call to receive the JSON response in the success callback.

I keep getting "Uncaught SyntaxError: Unexpected token o"

I'm trying to learn some html/css/javascript, so I'm writing myself a teaching project.
The idea was to have some vocabulary contained in a json file which would then be loaded into a table. I managed to load the file in and print out one of its values, after which I began writing the code to load the values into the table.
After doing that I started getting an error, so I removed all the code I had written, leaving me with only one line (the same line that had worked before) ... only the error is still there.
The error is as follows:
Uncaught SyntaxError: Unexpected token o
(anonymous function)script.js:10
jQuery.Callbacks.firejquery-1.7.js:1064
jQuery.Callbacks.self.fireWithjquery-1.7.js:1182
donejquery-1.7.js:7454
jQuery.ajaxTransport.send.callback
My javascript code is contained in a separate file and is simply this:
function loadPageIntoDiv(){
document.getElementById("wokabWeeks").style.display = "block";
}
function loadWokab(){
//also tried getJSON which threw the same error
jQuery.get('wokab.json', function(data) {
var glacier = JSON.parse(data);
});
}
And my JSON file just has the following right now:
[
{
"english": "bag",
"kana": "kaban",
"kanji": "K"
},
{
"english": "glasses",
"kana": "megane",
"kanji": "M"
}
]
Now the error is reported in line 11 which is the var glacier = JSON.parse(data); line.
When I remove the json file I get the error: "GET http://.../wokab.json 404 (Not Found)" so I know it's loading it (or at least trying to).

Looks like jQuery takes a guess about the datatype. It does the JSON parsing even though you're not calling getJSON()-- then when you try to call JSON.parse() on an object, you're getting the error.
Further explanation can be found in Aditya Mittal's answer.

The problem is very simple
jQuery.get('wokab.json', function(data) {
var glacier = JSON.parse(data);
});
You're parsing it twice. get uses the dataType='json', so data is already in json format.
Use $.ajax({ dataType: 'json' ... to specifically set the returned data type!

Basically if the response header is text/html you need to parse, and if the response header is application/json it is already parsed for you.
Parsed data from jquery success handler for text/html response:
var parsed = JSON.parse(data);
Parsed data from jquery success handler for application/json response:
var parsed = data;

Another hints for Unexpected token errors.
There are two major differences between javascript objects and json:
json data must be always quoted with double quotes.
keys must be quoted
Correct JSON
{
"english": "bag",
"kana": "kaban",
"kanji": "K"
}
Error JSON 1
{
'english': 'bag',
'kana': 'kaban',
'kanji': 'K'
}
Error JSON 2
{
english: "bag",
kana: "kaban",
kanji: "K"
}
Remark
This is not a direct answer for that question. But it's an answer for Unexpected token errors. So it may be help others who stumple upon that question.

Simply the response is already parsed, you don't need to parse it again. if you parse it again it will give you "unexpected token o" however you have to specify datatype in your request to be of type dataType='json'

I had a similar problem just now and my solution might help. I'm using an iframe to upload and convert an xml file to json and send it back behind the scenes, and Chrome was adding some garbage to the incoming data that only would show up intermittently and cause the "Uncaught SyntaxError: Unexpected token o" error.
I was accessing the iframe data like this:
$('#load-file-iframe').contents().text()
which worked fine on localhost, but when I uploaded it to the server it stopped working only with some files and only when loading the files in a certain order. I don't really know what caused it, but this fixed it. I changed the line above to
$('#load-file-iframe').contents().find('body').text()
once I noticed some garbage in the HTML response.
Long story short check your raw HTML response data and you might turn something up.

SyntaxError: Unexpected token o in JSON
This also happens when you forget to use the await keyword for a method that returns JSON data.
For example:
async function returnJSONData()
{
return "{\"prop\": 2}";
}
var json_str = returnJSONData();
var json_obj = JSON.parse(json_str);
will throw an error because of the missing await. What is actually returned is a Promise [object], not a string.
To fix just add await as you're supposed to:
var json_str = await returnJSONData();
This should be pretty obvious, but the error is called on JSON.parse, so it's easy to miss if there's some distance between your await method call and the JSON.parse call.

Make sure your JSON file does not have any trailing characters before or after. Maybe an unprintable one? You may want to try this way:
[{"english":"bag","kana":"kaban","kanji":"K"},{"english":"glasses","kana":"megane","kanji":"M"}]

const getCircularReplacer = () => {
const seen = new WeakSet();
return (key, value) => {
if (typeof value === "object" && value !== null) {
if (seen.has(value)) {
return;
}
seen.add(value);
}
return value;
};
};
JSON.stringify(tempActivity, getCircularReplacer());
Where tempActivity is fething the data which produces the error "SyntaxError: Unexpected token o in JSON at position 1 - Stack Overflow"