I am parsing JSON using the following example php syntax
$carModel = strip_tags($_REQUEST['car']['model']);
The only problem is that some times the "model" array is missing from the provided JSON. When this is the case my php script shuts down when it reaches that line. Can any one recommend a way to check for the model array before parsing so that my php scrip will still run if "model" isn't present.
Just check to see if it's there. If not assign a default value to it:
$carModel = (isset($_REQUEST['car']['model'])) ? strip_tags($_REQUEST['car']['model']) : '';
I'm not sure how this is related to json, but if you want to check if a variable exists before you use it, you can do:
if (isset($_REQUEST['car']['model']))
{
$carModel = strip_tags($_REQUEST['car']['model']);
}
Related
So i am using this PHP code to create the json output, and I am having an issue where it’s creating an array of array with the info. I would like to get rid of one array and just display the list of API’s thats been used and number that has been used.
Looks as though the difference is you have...
"apis":[{"item_search":"0\n"},{"item_recommended":"0\n"}]
and want
"apis":{"item_search":"0\n","item_recommended":"0\n"}
If this is the case, you need to change the way you build the data from just adding new objects each time to setting the key values directly in the array...
$zone_1 = [];
foreach($zone_1_apis as $api_name ) {
$zone_1[substr($api_name, 0,-5)] = file_get_contents('keys/'.$_GET['key'].'/zone_1/'.$api_name);
}
You also need to do the same for $zone_2 as well.
It may also be good to use trim() round some of the values as they also seem to contain \n characters, so perhaps...
trim(file_get_contents('keys/'.$_GET['key'].'/zone_1/'.$api_name))
PHP is unable to get the value for dynamic object prepared as:
$abc->{$dynamic_object_pattern}
Where the value of the variable $dynamic_object_pattern is, json->{'data_1'}->{'value'}
For me, PHP 7.1 is understanding the statically defined pattern like below, and fetching the value as it should:
$abc->json->{'data_1'}->{'value'}
But not when I put the whole portion into a variable and then try to get its value. I Tried,
$abc->{$dynamic_object_pattern} and $abc->$dynamic_object_pattern
both ways, but no solution yet.
The error comes is Notice: Undefined property: stdClass::$json->{'data_1'}->{'value'}
I'm attempting an answer without seeing your JSON data
Here you say :
But not when I put the whole portion into a variable and then try to
get its value
From that line alone it sounds like you are trying to get value from a string rather than array. If you put the whole portion into a variable, PHP will interpret it as string. Make sure you add array() before newly created variable.
Natural array :
$array = array();
Now a string
$variable = $array;
Convert string to array
$new_array = array($variable);
Also, have you tried decoding?
// decode
$response = json_decode($new_array, true);
//print out
var_export(array_unique(array($response)));
This is what I am trying to do. I am trying pass variable(s) from one form to another. I can do it in "HTML" I would like to have done in a PHP echo statement
When I call the second program from the first program I have nothing coming back in the "GET" array. I think ($v_resource_id, $v_category_id) are not being translated correctly What I am doing wrong in my syntax ? What you see here is part of the first program or calling program
echo'';
Aside from the noted html error (missing quote), you are not retrieving the correct keys, you have var and var2 but are trying to retrieve v_resource_id. You need to retrieve $_GET['var'] and $_GET['var2'].
Do print_r($_GET); to see what is being sent via $_GET. You should get:
Array (
[var] => whatever
[var2] => something else
)
Also, you may want to use the native query building function by doing http_build_query(array('var'=>'something','var2'=>'what ever')) to get a query string. Makes this easier and I think it takes care of urlencode(), you'd have to double check that.
Try this, it's about proper quoting
echo "here";
you'll use your values as $_GET['var'] and $_GET['var2']
So... I need to save a large-ish amount of data from a platform with an excruciatingly limited amount of memory.
Because of this, I'm basically storing the data on my webserver, using a php script to just write JSON to a flat file, because I'm lazy af.
I could go to the trouble of having it store the data in my mysql server, but frankly the flat file thing should have been trivial, but I've run up against a problem. There are several quick and dirty workarounds that would fix it, but I've been trying to fix it the "right" way (I know, I know, the right way would be to just store the data in mysql, but I actually need to be able to take the json file this produces and send it back to the platform that needs the data (In a ridiculously roundabout fashion), so it made sense to just have the php save it as a flat file in the first place. And It's already working, aside from this one issue, so I hate to reimpliment.
See... Because of the low memory on the platform I'm sending the json to my server from... I'm sending things one field at a time. Each call to the php script is only setting ONE field.
So basically what I'm doing is loading the file from disk if it exists, and running it through json_decode to get my storage object, and then the php file gets a key argument and a value argument, and if the key is something like "object1,object2", it explodes that, gets the length of the resulting array, and then stores the value in $data->$key[0]->$key[1].
Then it's saved back to disk with fwrite($file, json_encode($data));
This is all working perfectly. Except when $value is a simple string. If it's an array, it works perfectly. If it's a number, it works fine. If it's a string, I get null from json_decode. I have tried every way I can think of to force quotes on to the ends of the $value variable in the hopes of getting json_decode to recognize it. Nothing works.
I've tried setting $data->$key[0]->$key[1] = $value in cases where value is a string, and not an array or number. No dice, php just complains that I'm trying to set an object that doesn't exist. It's fine if I'm using the output of json_decode to set the field, but it simply will not accept a string on its own.
So I have no idea.
Does anyone know how I can either get json_decode to not choke on a string that's just a string, or add a new field to an existing php object without using the output of json_decode?
I'm sure there's something obvious I'm missing. It should be clear I'm no php guru. I've never really used arrays and objects in php, so their vagaries are not something I'm familiar with.
Solutions I'm already aware of, but would prefer to avoid, are: I could have the platform that's sending the post requests wrap single, non-numeric values with square braces, creating a single item array, but this shouldn't be necessary, as far as I'm aware, so doing this bothers me (And ends up costing me something like half a kilobyte of storage that shouldn't need to be used).
I could also change some of my json from objects to arrays in order to get php to let me add items more readily, but it seems like there should be a solution that doesn't require that, so I'd really prefer not to...
I skim through your post.
And I know this works for StdClass :
$yourClass->newField = $string;
Is this what you wanted ?
OK so... ultimately, as succinctly as possible, the problem was this:
Assuming we have this JSON in $data:
{
"key1":
{
"key2":["somedata","someotherdata"]
}
}
And we want it to be:
{
"key1":
{
"key2":["somedata","someotherdata"],
"key3":"key3data"
}
}
The php script has received "key=key1,key3&value=key3data" as its post data, and is initialized thusly:
$key = $_POST["key"];
$key = explode($key,",");
$value = $_POST["value"];
...which provides us with an array ($key) representing the nested json key we want to set as a field, and a variable ($value) holding the value we want to set it to.
Approach #1:
$data->$key[0]->$key[1] = json_decode($value);
...fails. It creates this JSON when we re-encode $data:
{
"key1":
{
"key2":["somedata","someotherdata"],
"key3":null
}
}
Approach #2:
$data->$key[0]->$key[1] = $value;
...also fails. It fails to insert the field into $data at all.
But then I realized... the problem with #2 is that it won't let me set the nonexistent field, and the problem with approach #1 is that it sets the field wrong.
So all I have to do is brute force it thusly:
$data->$key[0]->$key[1] = json_decode($value);
if (json_decode($value) == NULL)
{
$data->$key[0]->$key[1] = $value;
}
This works! Since Approach #1 has created the field (Albeit with the incorrect value), PHP now allows me to set the value of that field without complaint.
It's a very brute force sort of means of fixing the problem, and I'm sure there are better ones, if I understood PHP objects better. But this works, so at least I have my code working.
I got used to this notation for creating empty arrays and add named elements to them when needed;
$array = [];
// in case there is an error
$array["error"][] = "new error message as element 0 of $array['error']";
Now I learned that the [] notation for arrays does not work in older versions of PHP, like PHP 5.2.
Instead I have to do;
$array = array(
"error" => array()
);
array_push($array["error"], "new error message as element 0 of $array['error']");
This way is a little bit inconvenient in my case because the great thing about the first code snippet is that the "error" entry in $array is only created when there is an actual error, whereas in the latter case the entry (although empty) exists either way.
Is there a way to get similar 'functionality' (i.e. specifying/adding named elements when needed, not at initialisation) in a way that is also easily readable in PHP 5.2?
EDIT:
The first code snippet in the original post was reading $array = array[];. The author corrected it after I posted this answer.
The first code snipped is incorrect. There is no such thing as array[]. The correct syntax is array().
$array = array();
// in case there is an error
$array["error"][] = "new error message as element 0 of $array['error']";
You don't have to worry about PHP versions. This syntax always worked on PHP since its dawn and it will probably work forever. Keep using it.
The first way of creating array in PHP is incorrect. This syntax works in PHP5.2 below too, so you dont need to worry about it. You don't need to use array_push and simply do following.
The correct syntax is:
$array = array(); // notice it doesn't to array[]
// add error when there is one
$array["error"][] = "new error message as element 0 of $array['error']";