Scraping JSON data from an AJAX request - javascript

I have a PHP function that echoes out JSON data and pagination links. The data looks exactly like this.
[{"name":"John Doe","favourite":"cupcakes"},{"name":"Jane Citizen","favourite":"Baked beans"}]
Previous
Next
To get these data, I would use jQuery.ajax() function. My code are as follow:-
function loadData(page){
$.ajax
({
type: "POST",
url: "http://sandbox.dev/favourite/test",
data: "page="+page,
success: function(msg)
{
$("#area").ajaxComplete(function(event, request, settings)
{
$("#area").html(msg);
});
}
});
}
Using jQuery, is there anyway I can scrape the data returned from the AJAX request and use the JSON data? Or is there a better way of doing this? I'm just experimenting and would like to paginate JSON data.

It's better to not invent your own formats (like adding HTML links after JSON) for such things. JSON is already capable of holding any structure you need. For example you may use the following form:
{
"data": [
{"name": "John Doe", "favourite": "cupcakes"},
{"name": "Jane Citizen", "favourite": "Baked beans"}
],
"pagination": {
"prev": "previous page URL",
"next": "next page URL"
}
}
On client-side it can be parsed very easily:
$.ajax({
url: "URL",
dataType:'json',
success: function(resp) {
// use resp.data and resp.pagination here
}
});

Instead of scraping the JSON data i'd suggest you to return pure JSON data. As per your use case I don't think its necessary to write the Previous and Next. I am guessing that the first object in your return url is for Previous and the next one is for Next. Simply return the below string...
[{"name":"John Doe","favourite":"cupcakes"},{"name":"Jane Citizen","favourite":"Baked beans"}]
and read it as under.
function loadData(page){
$.ajax
({
type: "POST",
url: "http://sandbox.dev/favourite/test",
dataType:'json',
success: function(msg)
{
var previous = msg[0]; //This will give u your previous object and
var next = msg[1]; //this will give you your next object
//You can use prev and next here.
//$("#area").ajaxComplete(function(event, request, settings)
//{
// $("#area").html(msg);
//});
}
});
}
This way return only that data that's going to change not the entire html.

put a dataType to your ajax request to receive a json object or you will receive a string.
if you put "previous" and "next" in your json..that will be invalid.
function loadData(page){
$.ajax({
type: "POST",
url: "http://sandbox.dev/favourite/test",
data: {'page':page},
dataType:'json',
success: function(msg){
if(typeof (msg) == 'object'){
// do something...
}else{
alert('invalid json');
}
},
complete:function(){
//do something
}
});
}
and .. in your php file, put a header
header("Content-type:application/json");
// print your json..
To see your json object... use console.log , like this:
// your ajax....
success:(msg){
if( window.console ) console.dir( typeof(msg), msg);
}
Change your json to something like this: (Use jsonlint to validate it - http://jsonlint.com/)
{
"paginate": {
"previous": "http...previsouslink",
"next": "http...nextlink"
},
"data": [
{
"name": "JohnDoe",
"favourite": "cupcakes"
},
{
"name": "JaneCitizen",
"favourite": "Bakedbeans"
}
]
}

You can try this :-
var jsObject = JSON.parse(your_data);
data = JSON.parse(gvalues);
var result = data.key;
var result1 = data.values[0];

Related

Ajax sends two empty arrays and one filled, PHP receives only the full one

I'm completely new to PHP. Working with ajax, php and WordPress I'm sending an object with ajax:
let import_data = {
action: 'import_data',
data: {
first_array: [], // this one is empty
second_array: [], // this one too
third_array: [1,2,3] // this one is full
}
};
I've checked the import_data object many times right before it was sent. The php, however, always receives:
import_data = {
action: 'import_data',
data: {
third_array: [1,2,3]
}
}
The question is why is that happening and how can I achieve receiving all arrays, whether they are empty or not, i.e.
import_data = {
action: 'import_data',
data: {
first_array: [],
second_array: [],
third_array: [1,2,3]
}
}
I need to refactor a lot of code now due to this issue so I'm trying to solve it as easy as possible, but if there is a common known right way to deal with it I'll use it. Thanks in advance!
P.S. In case you wondering, yes, if all arrays being sent are full, php will receive all of them.
UPD In the comments I got I might've wanted to add contentType or json.strngify my data. It didn't help, but I might do it wrong, so I'll try to partly show my code below:
var import_data = {
action: 'start_import',
sliced_batch: {
rows_to_add: [],
rows_to_delete: [],
rows_to_update: [1,2,3,4,5,...]
}
};
function ajax_call(import_data) {
// ... processes
jQuery.ajax({
url: start_import_ajax.url, // url from php file
type: 'POST',
contentType: "text; charset=utf-8", // sending string with cyrillic (ukrainian lng)
dataType: 'application/json', // want to recieve json
data: JSON.stringify(import_data),
success: function(response) {
// ... processes import_data ...
if(it is the end of data) return;
else ajax_call(import_data);
},
error: function(e) {
// here is where I end up
}
}
PHP side is now pretty shy, as I just made a pause and wanted to see my data in console:
function start_import_callback() {
echo json_decode($_POST);
echo $_POST;
echo json_decode($_POST['sliced_batch']);
echo $_POST['sliced_batch'];
wp_die();
}
I've tried all echo's one by one, but always saw:
{
"readyState": 4,
"responseText": "0",
"status": 400,
"statusText": "error"
}
When NOT stringifying and NOT specifying contentType/dataType it returns:
{
action: 'import_data',
sliced_batch: {
rows_to_update:
{
"ID": "00000006125",
"CatalogueNumber": "bla, bla",
"Category": "bla, bla",
"Manufacturer": "bla",
"Nomenclature": "blablablablabla",
"NomenclatureUkrainian": "bla",
"StockStatus": "instock",
"Price": "2 315",
"Parent": "blabla",
"Sorting": "99"
},
{},...
]
}
}
So, rows_to_delete: [] and rows_to_add: [] are missing...
You are using jQuery dataType options wrong!
The dataType: value should be 'json' not 'application/json' because your value will request with HTTP accept: */* but if you use 'json' it will be accept: application/json.
Option 1
Use content type application/json.
The contentType: should be 'application/json' or 'application/json;charset=utf-8'.
By this content type you will be now able to receive POST data in JSON but you cannot access them with $_POST because the data is not valid application/x-www-form-urlencoded.
Full code for client side:
var import_data = {
action: 'start_import',
sliced_batch: {
rows_to_add: [],
rows_to_delete: [],
rows_to_update: [1,2,3,4,5]
}
};
function ajax_call(import_data) {
// ... processes
jQuery.ajax({
url: 'test.php', // url from php file
type: 'POST',
contentType: "application/json;charset=utf-8", // sending string with cyrillic (ukrainian lng)
dataType: 'json', // want to recieve json
data: JSON.stringify(import_data),
success: function(response) {
// ... processes import_data ...
},
error: function(e) {
// here is where I end up
}
});
}
Code for PHP:
$data = json_decode(file_get_contents('php://input'), true);
// use $data['sliced_batch'] to access `rows_to_add`, `rows_to_delete` etc.
Option 2
Use content type application/x-www-form-urlencoded.
With this content type, you will be able to access $_POST properly.
However, to use this request content type in header, the jQuery itself will be modify the value if it is empty jQuery will be just delete it!! So, you need to JSON string only sliced_batch property.
Here is the JS code:
var import_data = {
action: 'start_import',
sliced_batch: {
rows_to_add: [],
rows_to_delete: [],
rows_to_update: [1,2,3,4,5]
}
};
function ajax_call(import_data) {
// ... processes
// modify `sliced_batch` property to be JSON string to prevent jQuery remove empty properties.
import_data.sliced_batch = JSON.stringify(import_data.sliced_batch);
jQuery.ajax({
url: 'test.php', // url from php file
type: 'POST',
// just remove contentType option. It is no need.
//contentType: "application/json;charset=utf-8", // sending string with cyrillic (ukrainian lng)
dataType: 'json', // want to recieve json
data: import_data,
success: function(response) {
// ... processes import_data ...
},
error: function(e) {
// here is where I end up
}
});
}
PHP:
$sliced_batch = ($_POST['sliced_batch'] ?? '');
$sliced_batch = json_decode($sliced_batch, true);
// you can now access $sliced_batch['rows_to_add'], etc...
So, thanks once again to #vee for his explanation, but here's one more thing I'd like to share as it was crucial to get everything to work.
First, for json_decode method the JS object keys should be double-quoted, i.e. NOT
$bad_json = '{ bar: "baz" }';
json_decode($bad_json); // null
or
$bad_json = '{ 'bar': "baz" }';
json_decode($bad_json); // null
BUT
$bad_json = '{ "bar": "baz" }';
json_decode($bad_json); // array("bar" => "baz")
Second and most important!
When dealing with WordPress it sets its own rules and shows focuses!
Depending on what answer you'd like to get, you may want to use function wp_unslash(). Looking at the stringified data in console I saw somth like this:
"\u0421\u0435\u0440\u0432\u0435\u0440: \u0424\u0430\u0439\u043b\u0456\u0432 av_imp_p_WEB.csv \u0456 av_imp_p_WEB_previous.csv \u043d\u0435 \u0431\u0443\u043b\u043e \u0432\u0438\u044f\u0432\u043b\u0435\u043d\u043e. \u041f\u043e\u0447\u0438\u043d\u0430\u044e \u0456\u043c\u043f\u043e\u0440\u0442 \u0432\u0441\u044c\u043e\u0433\u043e
// it is more common for contentType: "application/x-www-form-urlencoded"
It is the dirty work of WooCommerce (as I read from another's people opinion) and it hinders parsing it the right way, so my full code is:
JS
var import_data = {
"action": "start_import",
"sliced_batch": {
"rows_to_add": my_data1,
"rows_to_delete": my_data2,
"rows_to_update": my_data3
}
};
function ajax_call(import_data) {
// ... processes
jQuery.ajax({ // ajax to php to save the file to uploads and move it to the plugin's folder
url: start_import_ajax.url, // url from php file
type: 'POST',
//contentType: "application/json;charset=utf-8", // what you send
dataType: 'JSON', // what you would like as a response
data: {
"action": import_data.action,
"sliced_batch": JSON.stringify(import_data.sliced_batch)
},
success: function(response) {
//response = JSON.parse(response); // if you'd like to console.log what you've sent
console.log(response);
}
....
PHP
$sliced_batch = wp_unslash($_POST['sliced_batch']);
$sliced_batch = json_decode($sliced_batch, true);
$result = start_import($sliced_batch);
if($result == 0) {
echo json_encode(["status" => 0]);
} else echo json_encode(["status" => 1]);

Iterating over the data received from ajax / json

Below is the type of data I am getting via ajax.
[{"model": "blogapp.articles", "pk": 1, "fields": {"title": "Rainbow Buildings in Tokyo", "slug": "Rainbow-Buildings-in-Tokyo"}}, {"model": "blogapp.articles", "pk": 2, "fields": {"title": "4 Cool Cube Facades", "slug": "4-Cool-Cube-Facades"}}]
How can I iterate over this data using .each to get the title and the slug for each entry?
The below code gives me a syntax error on the data.
app.js
$(document).ready(function () {
$(".tag-nav-links").on("click", function (e) {
e.stopPropagation();
return $.ajax({
type: "POST",
url: "",
dataType: "json",
data: { filter: `${e.target.textContent}` },
success: function (data) {
var html = "";
$(data).each(function (index, value) {
html += "<h4>{{" + value.title + "}}</h4>";
});
$("trial").append(html);
},
});
});
});
The jQuery function (which you're using like this: $(data)) isn't what you want there. (You may have meant $.each(data, ...), but these days there's no need.) If data really is an array as shown, just use map on it, then join the result together with a blank string:
success: function (data) {
$("trial").append(data.map(value => {
return "<h4>{{" + value.fields.title + "]]</h4>";
}).join(""));
},
If data is really as shown in the screenshot, then it's an object with a data property containing a string of JSON. That's probably a misconfiguration or coding error on the server, current it's returning text something like this:
{"data":"[{\"model\": \"blogapp.articles\", \"pk\": 1,...
when it should be returning something like this:
{"data":[{"model":"blogapp.articles","pk":1,...
Something is pre-stringifying the data before passing it to whatever wraps it in the {"data": ___} wrapper, stringifies it, and returns it.
Until/unless you fix it, you'll have to parse it twice. jQuery is doing one of those for you, but you'll have to do the second one, after which you should be able to use the array:
// Until/unless the server is fixed
success: function (data) {
data = JSON.parse(data.data); // *** Second parse
$("trial").append(data.map(value => {
return "<h4>{{" + value.fields.title + "]]</h4>";
}).join(""));
},
If you fix the server so it's not double-stringifying, you'd use data.data instead (since data is your parameter name, and it refers to an object with a data property that has the array you want to use):
// After the server is fixed
success: function (data) {
$("trial").append(data.data.map(value => {
// ^^^^^^^^^
return "<h4>{{" + value.fields.title + "]]</h4>";
}).join(""));
},

JSON Data cannot be stored in variable

Im trying to load the content of a JSON File into an variable.
Before, the variable looked something like this:
var Data = {
teams : [
["Team 1", "Team 2"],
["Team 3", "Team 4"]
],
results : [
[[1,2], [3,4]],
[[4,6], [2,1]]
]}
Now I have a JSON File looking something like this:
{"teams":[["Team 1","Team 2"],["Team 3","Team 4"],"results":[[[[1,2],[3,4]],[[4,6],[2,1]]]}
Now I want that the the content of the JSON File is stored in the Data Variable before. I tried it with Ajax which looks like this:
$.ajax({
type: "GET",
dataType : 'json',
async: true,
url: 'data.json',
success: function(data) {
console.log(data)
var Data = data
},
});
Console.log works perfect, but the Data is not saved in the variable and I'm getting the error: Uncaught ReferenceError: Data is not defined.
I also tried it with var Data = JSON.parse(data), but this doesn't seem to work either.
And now I'm stuck without any clue.
Thanks for help in advance.
I'm not sure what your code looks like after the ajax call, but I'm guessing the the code where you are using Data is after the ajax call. ajax is asynchrounous. That means that your code doesn't wait for it to finish before moving on. Any code that needs to wait until after it's done fetching the data, you can put in the .success function. Also, it's worth noting that success only gets called when the ajax request is successful. If you want to handle errors, you can use .error Something like this should work:
$.ajax({
type: "GET",
dataType : 'json',
async: true,
url: 'data.json',
success: function(data) {
console.log(data)
var Data = data;
// Anything that needs to use Data would go inside here
},
error: function(err) {
// handle errors
console.error(err);
}
});
// Any code here will not wait until `Data` is defined
// console.log(Data) // error

Parse a json reply from a jquery result in php

I have a simple search form which query an external server for result with jquery
$("#formsearch").on("submit", function (event) {
// everything looks good!
event.preventDefault();
submitFormSearch();
});
function submitFormSearch(){
// Initiate Variables With Form Content
var searchinput = $("#searchinput").val();
$.ajax({
type: "GET",
url: "https://external-server/api/",
headers: {"Authorization": "xxxxxxxxxxxxxx"},
data: "action=Search&query="+searchinput,
success:function(json){
console.log(json);
$.ajax({
type: "POST",
url:'search_func.php',
data: "func=parse&json="+json,
success:function(data) {
console.log(data);
$('#risultato_ricerca').html(data);
}
});
}
});
}
The first GET ajax works properly and I get correct data but trying to send this json data to my php script in post I can't get data.
This is the code in search_func.php
if(isset($_POST['func']) && !empty($_POST['func'])){
switch($_POST['func']){
case 'parse':
parse($_POST['json']);
break;
default:
break;
}
}
function parse($json) {
$obj = json_decode($json,true);
var_dump($obj);
}
... it displays NULL
Where I'm wrong ?
EDIT:
SOLVED
changing:
data: "func=parse&json="+json,
to:
data: { func: 'parse', json: JSON.stringify(json) },
json code is correctly passed to search_func.php
Changed function parse in php file to:
function parse($json) {
$data = json_decode(stripslashes($json),true);
print_r($data);
}
Thank you.
Is the javascript json variable correctly filled (i.e. what does your console show you?) Possible you must encode the json variable to a string before posting.
i.e: instead of data: "func=parse&json="+json, use data: "func=parse&json="+JSON.stringify(json),
See this: http://api.jquery.com/jquery.ajax/
The correct syntax is: data: { func: 'parse', json: my_json_here }
If this doesn't works is probably that you have to encode the JSON to a string (see JSON.stringify())

accessing json data from jquery

I'm creating an ajax app using jQuery 1.4.2 and I've tried using using get(), post() and the ajax() method itself. My php service returns:
[{"k":"label0","v":0.5},{"k":"label1","v":99.43},{"k":"label2","v":2.46},{"k":"label3","v":46.29},{"status":"OK"}]
in my success callback I have tried accessing as json.status and json[0][0]
but it always returns "undefined". what am I doing wrong?
function getSysinfo(source) {
var json = null;
$.ajax({
url: source,
type: 'POST',
dataType: 'json',
success: function (data) {
json = eval("(" + data + ")");
$('#data').html(json.status);
alert(json[0][0]);
refreshChart(json);
},
error: function (request, status, error) {
alert("REQUEST:\t" + request + "\nSTATUS:\t" + status +
"\nERROR:\t" + error);
}
});
return json;
}
I've been googling this for days. How the heck do I access the returned data? any help would be appreciated.
To access that status value you would need:
data[4].status
This is because it is an object stored in the the fifth element in an array, with status being a property on the object.
Your JSON-data looks like this:
[
{
"k": "label0",
"v": 0.5
},
{
"k": "label1",
"v": 99.43
},
{
"k": "label2",
"v": 2.46
},
{
"k": "label3",
"v": 46.29
},
{
"status": "OK"
}
]
You would have to read your status using
json[4].status
with the 4 as a magical number or length-1 - not desirable. I would consider modifying your servers response to something more useful like this:
{
"status": "OK",
"entries": [ ... ] // add your data here
}
In your success callback try:
var parsed = $.parseJSON(data);
$.each(parsed, function (i, jsondata) {
alert( jsondata.k );
alert( jsondata.v );
});
You don't need the eval("("+data+")");. jQuery is automatically parsing the JSON response for you because you specified dataType:'json'
From the jQuery docs for dataType:
"json": Evaluates the response as JSON and returns a JavaScript object. In jQuery 1.4 the JSON data is parsed in a strict manner; any malformed JSON is rejected and a parse error is thrown. (See json.org for more information on proper JSON formatting.)
no need to use eval any more use below code which can be more for json
$.getJSON(url+query,function(json){
$.each(json,function(i,value){
});
});
nategood already wrote that you don't need do do anything with data, it's already an object.
In this case it's an array, if you like to access the status, you need to retrieve it from the last item of the data-array(that's where you'll find it in this array):
data[data.length-1].status
But maybe you should think about another structure of your JSON, it doesn't look very comfortable.
Something like that:
{
"items":[
{"k":"label0","v":0.5},
{"k":"label1","v":99.43},
{"k":"label2","v":2.46},
{"k":"label3","v":46.29}
],
"status":"OK"
}
...should be easier to handle, because you can simply access data.status instead of first looking where you may find it inside the response(what may be error-prone ).
The data parameter is the decoded JSON as you can see in this example:
http://www.jsfiddle.net/rLprV/1/
$.ajax({
url: url,
type: 'POST',
dataType: 'json',
data: formData,
showLoader:true,
success: function (response) {
var parsed = JSON.parse(JSON.stringify(response));
$.each(parsed, function (key, val) {
alert( val.name );
});
},
error: function (err) {
alert("Please enter a valid id")
}
});

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