storing live data in Mongodb

Question

I am pushing data to a server using an API from a website. Every time my arduino detects a pulse it sends it to COSM. And by using a trigger, the data goes to my server. I was initially writing the data into a .txt file and a Json object, but now I want to start implementing mongo to have different collections.

For some reason the data is not being transmitted to my server after I added the Mongo connection when I tried to write it as a Mongo collection. I want to be able to write down the information in Mongo directly and avoid creating files.

Any suggestion is more than welcome, here is the code:

<?php

// Creating a data base in Mongodb to store my information from my $jsonFile
$connection = new MongoClient(); //Connect to mongo
$db = $connection -> qandm; // select my DB which is called qandM
$collection = $db -> pulseData;

//Gets all the information from Cosm
$pulse = $_POST['body'];

//access and open a file
//echo $pulse;

//Converts the data into PHP arrays
$pulseObj = json_decode($pulse, true);

//Parse through the specific information from the array and gets each piece of information in an array
$userName = $pulseObj["triggering_datastream"]["id"];
$dataTime= $pulseObj["triggering_datastream"]["at"];
$dataValue= $pulseObj["triggering_datastream"]["value"]["value"];


//Writes all the data coming from COSM
$file = fopen("data.txt", "a+");//a+ give the option to have the cursor at the end to access the file read and write it
    /*  $pulse.="\r\n"; */
fwrite($file, $pulse);//takes incoming data and writes it in the file
fclose($file);

//Opens a new .txt file and writes the values that we selected before into our file
$string = $userName." ".$dataTime." ".$dataValue." \r\n";
//error_log allows me to see in my Apache log server the information that I'm printing
error_log($string);

//Write all the information I parsed in my three variables in a new file
$file2 = fopen("rawData.txt", "a+");
fwrite($file2,$string);
fclose($file2);

//json sample

//Inputs the data from the time and the pulse value into a json object
$json = array("User" => $userName, "timestamp"=> $dataTime, "value"=> $dataValue);

//Opens a new json object
$jsonFile = fopen("data.json", "a+");

//Writes the data of our new arrayed information into the open json object
fwrite($jsonFile, json_encode($json));
fclose($jsonFile);




//A loop to populate
foreach($json as $data){
    $collection->insert($data);

}

//find the data I just stored
$cursor = $collection->find();

//Output it in a UL
echo "<p> My Pulse </p>";

echo '<ul>';
foreach($cursor as $doc){

    echo' <li> My pulse is: '.$doc['value'];

}
 echo '</ul>';


/*$data = "data.txt";
$fh = fopen($data, "w") or die ("can't open file");
$data = json_encode($_POST);
fwrite($fh, $data);
fclose($fh);*/

//print_r($file);



?>

Answer 1

This is likely the source of your problems:

//A loop to populate
foreach($json as $data){
    $collection->insert($data);

}

You are iterating over your $json array and passing the values (but not the keys) to the insert method of MongoCollection. According to the doc this method expects an object or an array. Based on what I understand your code to be trying to do this foreach loop should be replaced with the following:

$collection->insert($json);

This will create a mongo object resembling your array. Your code currently is attempting to insert the values of each array element as an individual entry.