I have some PHP code that outputs a JSON array when $.getJSON is called:
.
.
.
$data = array_combine($date_dispatched,$amount);
echo json_encode($data);
This is collected by:
$.getJSON('statistics_get.php',function(output) {
$.plot($("#graph_1"), [{
data: output,
lines: {show:true}
}]
);
});
Now, using firebug, the response I get back is of the form:
{"0":"0","1296658458000":"566","1296725534000":"789","1297072385000":"890","1297072388000":"435"}
Flot is not processing this data. I believe Flot needs it to be in the form [[1,2],[4,5],[6,9]] etc. So my question is, what is the best way of getting this JSON array into the correct form for flot to read and produce a graph.
If you look at example two here: http://php.net/manual/en/function.json-encode.php
you will see that you can have json_encode return an array instead of an associative object
Would that not be the solution rather than
var flotArr = []
var cnt=0;
for (var o in data) flotArr[cnt++]=[o,data[o]]
Don't use array_combine, since it doesn't do what you need. Doing "zip" in PHP is a little bit unpleasant, but you should be able to manage with:
function make_pair($date, $amount) {
return array($date, $amount);
}
$data = array_map('make_pair', $date_dispatched, $amount);
And then JSON-encode that.
Related
I've been experiencing a lot of trouble with my issue all afternoon. Endless searches on Google and SO haven't helped me unfortunately.
The issue
I need to send an array to a PHP script using jQuery AJAX every 30 seconds. After constructing the array and sending it to the PHP file I seemingly get stuck. I can't seem to properly decode the array, it gives me null when I look at my console.
The scripts
This is what I have so far. I am running jQuery 1.11.1 and PHP version 5.3.28 by the way.
The jQuery/Ajax part
$(document).ready(function(){
$.ajaxSetup({cache: false});
var interval = 30000;
// var ids = ['1','2','3'];
var ids = []; // This creates an array like this: ['1','2','3']
$(".player").each(function() {
ids.push(this.id);
});
setInterval(function() {
$.ajax({
type: "POST",
url: "includes/fetchstatus.php",
data: {"players" : ids},
dataType: "json",
success: function(data) {
console.log(data);
}
});
}, interval);
});
The PHP part (fetchstatus.php)
if (isset($_POST["players"])) {
$data = json_decode($_POST["players"], true);
header('Content-Type: application/json');
echo json_encode($data);
}
What I'd like
After decoding the JSON array I'd like to foreach loop it in order to get specific information from the rows in the database belonging to a certain id. In my case the rows 1, 2 and 3.
But I don't know if the decoded array is actually ready for looping. My experience with the console is minimal and I have no idea how to check if it's okay.
All the information belonging to the rows with those id's are then bundled into a new array, json encoded and then sent back in a success callback. Elements in the DOM are then altered using the information sent in this array.
Could someone tell me what exactly I am doing wrong/missing?
Perhaps the answer is easier than I think but I can't seem to find out myself.
Best regards,
Peter
The jQuery.ajax option dataType is just for the servers answer. What type of anser are you expexting from 'fetchstatus.php'. And it's right, it's json. But what you send to this file via post method is not json.
You don't have to json_decode the $_POST data. Try outputting the POST data with var_dump($_POST).
And what happens if 'players' is not given as parameter? Then no JSON is returning. Change your 'fetchstatus.php' like this:
$returningData = array(); // or 'false'
$data = #$_POST['players']; // # supresses PHP notices if key 'players' is not defined
if (!empty($data) && is_array($data))
{
var_dump($data); // dump the whole 'players' array
foreach($data as $key => $value)
{
var_dump($value); // dump only one player id per iteration
// do something with your database
}
$returningData = $data;
}
header('Content-Type: application/json');
echo json_encode($returningData);
Using JSON:
You can simply use your returning JSON data in jQuery, e.g. like this:
// replace ["1", "2", "3"] with the 'data' variable
jQuery.each(["1", "2", "3"], function( index, value ) {
console.log( index + ": " + value );
});
And if you fill your $data variable on PHP side, use your player id as array key and an array with additional data as value e.g. this following structure:
$data = array(
1 => array(
// data from DB for player with ID 1
),
2 => array(
// data from DB for player with ID 2
),
...
);
// [...]
echo json_decode($data);
What I suspect is that the data posted is not in the proper JSON format. You need to use JSON.stringify() to encode an array in javascript. Here is an example of building JSON.
In JS you can use console.log('something'); to see the output in browser console window. To see posted data in php you can do echo '<pre>'; print_r($someArrayOrObjectOrAnything); die();.
print_r prints human-readable information about a variable
So in your case use echo '<pre>'; print_r($_POST); to see if something is actually posted or not.
I have a JSON encoded array, to which i am returning to an AJAX request.
I need to place the JSON array into a JS Array so i can cycle through each array of data to perform an action.
Q. How do i place the JSON array contents into a JS array efficiently?
The PHP/JSON Returned to the AJAX
$sql = 'SELECT *
FROM btn_color_presets
';
$result = mysqli_query($sql);
$array = array(); //
while($row = mysql_fetch_assoc($result)) //
{
$array[] = $row;
$index++;
}
header("Content-type: application/json");
echo json_encode($array);
You can use JSON.parse function to do so:
var myObject = JSON.parse(response_from_php);
// loop over each item
for (var i in myObject) {
if (myObject.hasOwnProperty(i)) {
console.log(myObject[i]);
}
}
You can also use jQuery.parseJSON() if you are using jQuery, however jQuery also uses same function under the hood as priority if available.
Adding to Safraz answer:
If you're using jQuery, there's another way to do that. Simply add json as last parameter to your ajax calls. It tells jQuery that some json content will be returned, so success function get already parsed json.
Below example shows you simple way to achieve this. There's simple json property accessing (result.message), as well as each loop that iterates through whole array/object. If you will return more structurized json, containing list of object, you can access it inside each loop calling value.objectfield.
Example:
//Assuming, that your `json` looks like this:
{
message: 'Hello!',
result: 1
}
$.post(
'example.com',
{data1: 1, data2: 2},
function(response){
console.log(response.message) //prints 'hello'
console.log(response.result) //prints '1'
//iterate throught every field in json:
$(response).each(function(index, value){
console.log("key: " + index + " value: " + value);
});
},
'json'
)
Im trying to query a database from a php file then return the results (userLOC of each row) to the calling Jquery function.
Calling Jquery:
$.post(url, data, function (data)
{
alert(data);
})
relavent PHP:
$sql = "Select * from location";
$result = mysql_query($sql);
$stack = array();
while($row = mysql_fetch_array($result))
{
array_push($stack, $row["userLOC"]);
}
return $stack;
The problem is that I cant return it correctly, if I "echo $stack" it does not work it says Im trying to convert the array to string. If I "echo $stack[0]" it will give me the first result in the array correctly so I know the values are being stored correctly (as are $stack[1], etc.) but this only sends the one value back. And if I "return $stack" as pictured nothing is alerted because nothing is echoed. How would I go about getting the whole array back so that I could iterate through and use them on the jquery side?
In PHP
$foo = array();
echo $foo;
will produce the literal string Array as output.
You need to convert your array into a string. Since you're dealing with a Javascript target, use JSON as the perfect means of doing so:
$foo = array('a', 'b', 'c', 'd', 'e');
echo json_encode($foo);
Then in your JS code:
$.get(...., function (data) {
alert(data[1]); // spits out 'b'
});
Just remember to tell jquery that you're expecting JSON output.
You need to wrap (serialize) the data in a way that can be transported to the client via HTTP and used to get the original data.
Usual container formats are XML and JSON. JSON is well suited for usage in JavaScript, so use the PHP function json_encode() and echo the result.
Youll want to use JSON!
Client-side:
jQuery.post(url, data, function( data ) {
//Data is already converted from JSON
}, "json");
Server-side:
return json_encode($stack);
Explanation
Hope this helps!
echo json_encode($stack); can help you
at jquery side use jQuery.parseJSON()
You need to convert the array to a JSON object like this : return json_encode($stack);
Just convert your array it to a JSON object and return it back to your JavaScript:
return json_encode($stack);
As others have said, you may wish to wrap the output using something like json:
echo json_encode($stack);
However, if you aren't looking for an output with the complexity of JSON formatting, you could just use implode() to output a comma separated list:
echo implode(',',$stack);
I´ve got the following JSON string:
{"Data":{"Recipes":{"Recipe_5":{"ID":"5","TITLE":"Spaghetti Bolognese"},"Recipe_7":{"ID":"7","TITLE":"Wurstel"},"Recipe_9":{"ID":"9","TITLE":"Schnitzel"},"Recipe_10":{"ID":"10","TITLE":null},"Recipe_19":{"ID":"19","TITLE":null},"Recipe_20":{"ID":"20","TITLE":"Hundefutter"},"Recipe_26":{"ID":"26","TITLE":"Apfelstrudel"},"Recipe_37":{"ID":"37","TITLE":null},"Recipe_38":{"ID":"38","TITLE":"AENDERUNG"},"Recipe_39":{"ID":"39","TITLE":null},"Recipe_40":{"ID":"40","TITLE":"Schnitzel"},"Recipe_42":{"ID":"42","TITLE":"Release-Test"},"Recipe_43":{"ID":"43","TITLE":"Wurstel2"}},"recipes_id":{"ranking_1":"9","ranking_2":"10","ranking_3":"7","ranking_4":"5"}},"Message":null,"Code":200}
How can I parse it in PHP and extract a list of TITLEs?
You can use the function json_decode to parse JSON data in PHP (>= 5.2.0, at least). Once you have a PHP object, it should be easy to iterate over all recipes/members and access their titles, using something like this:
$data = json_decode($json, true); // yields associative arrays instead of objects
foreach ($data['Data']['Recipes'] as $key => $recipe) {
echo $recipe['TITLE'];
}
(Sorry I can't actually run this code right now. Hope it helps anyway.)
If you want to do that in JavaScript, you can simply access JSON data like "normal" objects:
var jsonData = {
"Data": {"Recipes": {"Recipe_5": {"ID":"5","TITLE":"Spaghetti Bolognese"}}}
// more data
};
alert(jsonData.Data.Recipes.Recipe_5.TITLE);
This will print the TITLE of Recipe_5 in a message box.
EDIT:
If you want all the titles in a list, you can do something like this:
var titles = [];
for (var key in jsonData.Data.Recipes) {
var recipe = jsonData.Data.Recipes[key];
titles.push(recipe.TITLE);
}
alert(titles);
Here is my PHP code, it's getting a listing of collections from mongodb
$list = $db->dbname->listCollections();
$result = array();
$i=0;
foreach ($list as $thiscollection) {
$result[$i++] = $thiscollection->getName();
}
echo json_encode( $result );
I do console.log in the callback and this is what I see.
["fruits", "dogs", "cars", "countries"]
The problem is that this is a string, not an array. I need to iterate through these values. How an I make this into a real object or get php to give me json rather than php array so I can use parseJSON on it.
Thanks.
js:
$.post('/ajax-database.php', function (data) {
console.log($.parseJSON(data));
$.each(data, function (key, value) {
console.log(value);
});
});
I see you are using jquery, if you want data to come back to you as a json object you need to do 1 of 2 things.
add header("Content-Type: application/json") to your php file, this will tell jquery to convert it to a json object instead of as text
Add a forth parameter to your $.post,
$.post('/ajax-database.php', function (data) {
console.log($.parseJSON(data));
$.each(data, function (key, value) {
console.log(value);
});
}, "json");
that will tell jquery to call your error handler if its NOT json, like if your php code fails and outputs html instead. You really should use $.ajax, i have no idea why anyone uses $.post, you can't do ANY meaningful error handling.
JSON is strings. If you want to be able to iterate over it then you need to decode it.