How do I add to a .json file with PHP? Currently, I'm appending a .json file with PHP, but it won't add the data to an existing JSON object. It makes a new object. I need the data all stored in one object, in an external JSON file. Basically, I have a JSON object and want to add more values to it.
$jsonFile = "test.json";
$fh = fopen($jsonFile, 'w');
$json = json_encode(array("message" => $name, "latitude" => $lat, "longitude" => $lon, "it" => $it));
fwrite($fh, $json);
You can decode the json file to a php array, then insert new data and save it again.
<?php
$file = file_get_contents('data.json');
$data = json_decode($file);
unset($file);//prevent memory leaks for large json.
//insert data here
$data[] = array('data'=>'some data');
//save the file
file_put_contents('data.json',json_encode($data));
unset($data);//release memory
what's suggested above is the hard way. i am considering there should be an easier way, to literally append an array into the json file.
here is the algo:
$handle=fopen($jsonFile);
fseek($handle,-1,SEEK_END);
fwrite($handle,$arrayToAdd);
fclose($handle);
but i am not sure it's more cpu/memory efficient to do so than reading the whole json file into memory, adding the array and then getting it stored.
Related
I was given a task to sort out data from a text file into JSON using PHP and object oriented principal.
The text file has information and is displayed as follows (ignore #):
#product_num:name:cost
5:tv:59.99
7:radio:10.99
I created a class and in this class I have one function that ignores any # or blank spaces from the data and puts the data in an array and json_encode it. When I echo this data it looks like this:
[{"1":"5:tv:59.99","2":"7:radio:10.99"}]
Is it possible to write other functions to separate the data further, for example so it looks more like:
[{"product_number":"5","name":"tv","cost":"59.99"},{"product_number":"7","name":"radio","cost":"10.99"}]
If so can anyone give me any pointers and tips because I have no idea where or how to begin even after numerous google searches.
There is a function inside PHP for reading value separated lines, like CSV; it's called fgetcsv which can also be used in object oriented PHP through SplFileObject::fgetcsv.
You will need to read each line, add the variable labels then append that to an array.
Depending on the size of the file you may need to optimize for memory usage as your array grows by saving as you proceed through the file.
<?php
$file = new SplFileObject('test.txt', 'r'); //Load the file
$file->current(); //Skip the first line (Side note: seek(1) did not appear to work while testing)
$result = [];
do { //While there are lines in the file
list($product_num, $name, $cost) = $file->fgetcsv(':'); //Break the line on the : delimiter into an array and populate the array into the three named values
$result[] = [ //Build the new json representation and add to result array
'product_num' => $product_num,
'name' => $name,
'cost' => $cost,
];
} while (!$file->eof());
file_put_contents('output.json', json_encode($result)); //Save the result
Your file format is basically a csv file and PHP has a CSV import function.
http://php.net/manual/en/function.fgetcsv.php
If you scroll down and check the CsvImporter example, you can copy/paste that and add a json_encode:
$importer = new CsvImporter("small.txt",true,":");
$data = $importer->get();
echo json_encode($data);
[{
"\ufeff#product_num": "5",
"name": "tv",
"cost": "59.99"
},
{
"\ufeff#product_num": "7",
"name": "radio",
"cost": "10.99"
}]
I need to update my JSON array in the file jsonData_0_123.json. I can get the data from the file and decode it, but I can't update the data in the file (in this case, the array answers)
$contents = file_get_contents('json_files/jsonData_0_123.json');
//Decode the JSON data into a PHP array.
$contentsDecoded = json_decode($contents, true);
//Update the decoded array
$contentsDecoded[1]["answers"] = "hello";
//Encode the array back into a JSON string.
$json = json_encode($contentsDecoded);
//Save the file.
file_put_contents('json_files/jsonData_0_123.json', $json);
I tried your code it is updating in json file with array answers.I found problem with file permission error for (jsonData_0_123.json) writing data into it.Otherwise it's working fine.
I'm working on a project that needs to add JSON to the file after every form submission.
My goal is to get the JSON to look like:
{
"word0":[
"cheese",
"burger"
],
"word1":[
"sup",
"boi"
],
"word2":[
"nothin'",
"much"
]
}
But I'm not able to add to the JSON file afterwards.
EDIT: I'm thinking about just creating a new file for every form submission. Would this be a better option?
(Storage size isn't a problem)
Here's my current code that places JSON into a file:
$response['word' . $count] = array('word1' => $_POST['firstrow'], 'word2' => $_POST['secondrow']);
file_put_contents("query.json", file_get_contents("query.json") . json_encode($response) . "\n");
Well if you have no problem with storage size you can do a new file for every form submission.
But you can make it one large file via reading the writing the file.
$data = json_decode(file_get_contents("data.json"), true);
$data["word3"] = array("i don't" , "know");
file_put_contents("data.json", json_encode($data));
If you want to save on your IO, you can do writing at a specific position via fseek.
$file = fopen("data.json", "c");
fseek($file, -5, SEEK_END); // 5 character back from the end of the file.
fwrite($file, $newJsonArrayElement);
fclose($file);
^^^^^^^^^^^^^^^^^^^^^^^^^
this is an example snipper, you will need to calculate the characters to seek back from the end and somehow generate the new json.
Working on a website and need to store data for each user. Currently using json files and the way it is set up currently it overwrites the data each time.
1st question, is using one json file the best way to house this data or should I set up a directory for each user?
2nd question, if one file is the best way to go, how do I append 'unique' data? I found some example code from the posts on "Overwrite JSON if fields match PHP" but it is not working for me. It is not writing to the file at all now.
Original code:
$posts[] = array('vhclID'=> $vhclID, 'statVal1'=> $engStat, 'statVal2'=> $brakeStat);
$response['posts'] = $posts;
$fp = fopen('results.json', 'w');
fwrite($fp, json_encode($response));
fclose($fp);
Revised code to be able to append new data and eliminate redundancies(Does not work):
$file = file_get_contents('results.json');
$data = json_decode($file);
unset($file);//prevent memory leaks for large json.
//insert data here
$data[vhclID] = array('vhclID'=> $vhclID, 'statVal1'=> $engStat,
'statVal2'=> $brakeStat);
//save the file
$data = array_values($data);
file_put_contents('results.json',json_encode($data));
echo json_encode($data);
unset($data);//release memory
Thanks for your help!!
You should use a database if you're storing typical user data; clearly you don't want to load megabytes of user data just to observer or modify one field for one user.
If you have some posted data, and I understand your question correctly, you might do something like this (but add more security):
$new_data = $_POST[];
foreach ($new_data as $name=>$datum) {
if (empty($data[vhclID][$name]) {
// This means that this field is unique
$data[vhclID][$name] = $datum;
}
}
And then just save that data to your JSON file.
$fp = fopen('results.json', 'r');
$postjson = json_decode(fread($fp, 1024*1024), true);
fclose($fp);
$posts = ($posts==array()) array('vhclID'=> $vhclID, 'statVal1'=> $engStat, 'statVal2'=> $brakeStat) : $postjson['posts'];
$response['posts'] = $posts;
$fp = fopen('results.json', 'w');
fwrite($fp, json_encode($response));
fclose($fp);
Should do what you want.
Modify $posts.
I mess around with PHP and json data a lot.
One thing I've noticed is that json_decode will create a PHP object(stdClass) by default
Example
Contents of results.json >>> {"example":"test"}
$file = file_get_contents("results.json");
$json = json_decode($file);
var_dump($json); // Outputs: object(stdClass)#14 (1) { ["example"]=> string(4) "test" }
If you add true as the second parameter to json_decode you end up with an array instead
Example
$file = file_get_contents("results.json");
$json = json_decode($file, TRUE); // Added TRUE as second parameter
var_dump($json); // Outputs: array(1) { ["example"]=> string(4) "test" }
Once you have your appropriate data, you can modify and change the $json however you want and then re-write it to the .json file.
So for question 1: Having an individual json file for each user (eg: userID-001.json, userID-002.json) is probably the better way to go.
For question 2: You can take the individual file, grab the contents and store it in a PHP array using json_decode($data, TRUE) // with true as second parameter if you want an array and then modify the array and resave it (using json_encode).
Hope this helps~!
Here is a JSON data example saved in a file data.txt
[
{"name":"yekky"},
{"name":"mussie"},
{"name":"jessecasicas"}
...// many rows
]
I would like to update the file so it will look like this:
[
{"name":"yekky","num":"1"},
{"name":"mussie","num":"2"},
{"name":"jessecasicas","num":"3"}
...// many rows
]
This is what I have got so far:
$json_data = file_get_contents('data.txt');
// What goes here?
And how do I count how many rows there are in the JSON tree?
Use json_decode() to decode the JSON data in a PHP array, manipulate the PHP array, then re-encode the data with json_encode().
For example:
$json_data = json_decode(file_get_contents('data.txt'), true);
for ($i = 0, $len = count($json_data); $i < $len; ++$i) {
$json_data[$i]['num'] = (string) ($i + 1);
}
file_put_contents('data.txt', json_encode($json_data));
You should use the PHP JSON library for such tasks. For example, after having read your JSON data from the file, do something like:
$json = json_decode($json_data);
$itemCount = count($json);
After having modified your JSON data, just encode it again:
$json_data = json_encode($json);
Also, you seem to want to beatify your JSON data. My advise is to just use whatever comes out of json_encode and save that to your file, because it will probably be the smallest (in file size) possible representation of your JSON data.
If you format it in a way readable for humans, you've got lots of extra spaces / tabs / line-breaks which increase file size and parsing time.
If you need to read it yourself, you can still beautify your JSON data by hand.
$file = 'data.txt';
$data = json_decode(file_get_contents($file));
foreach ($data as $key => $obj) {
$obj->num = (string)($key+1);
}
file_put_contents($file, json_encode($data));