ammaps / amcharts using dataLoader and passing post

Question

Using ammaps' dataLoader, is there a way to pass post parameters to an external file?

I'm creating a report that contains a map, which when clicked, will provide a list of news articles from a MySQL table. I'm pulling in json data using dataLoader. However, I need to be able to pass a value (reportId) to the script that generates the json file.

here's my code:

var map = AmCharts.makeChart("mapdiv", {
  type: "map",
  "dataLoader": {
    "url": "maparticlesfeed.json.php",
    "format":"json",
    "showErrors": false//,
    // tried this:  
    //"type" : "post",
    //"data" : {"reportIdFromPost" : 1}
  },
. . . //the rest of the map config 

And this is maparticlesfeed.json.php:

<?php include('database-connect.php'); 
$con=Database::connect();
$query=$con->prepare("SELECT * from articles Where reportId=$POST['reportIdFromPost']");
$query=>execute();
$articlesList=$query->fetchall(PDO::FETCH_ASSOC);
?>

{
"map" : "MyMapName",
"_comment" : "Here, instead of hard-coding the headlines, we will iterate through $articlesList",
"areas" : [   
    { "title" : "Virginia",
        "id" : "US-VA", 
        "selectable" : true,
        "numArticles" : 4,
        "articles" : [
            { "headline" : "This is the first headline",
                "link" : "link url"
            },
            { "headline" : "This is the second headline",
                "link" : "link url"
            },
            { "headline" : "This is the third headline",
                "link" : "link url"
            },
            { "headline" : "This is the fourth headline",
                "link" : "link url"
            }
        ]
    },
    { "title" : "Tennessee",
        "id" : "US-TN", 
        "selectable" : false,
        "numArticles" : 6
    } 
  ]
} 

Answer 1

I went the jQuery route to solve this. I'd still like to know if there's a way to do this with dataLoader, but here's a workaround in case anyone else has this issue in the future:

$.ajax({
  dataType: "json",
  url: "maparticlesfeed.json.php",
  data: { reportIdFromPost: 1 },
  type: "post",
  success: function(data){ 
    console.log(data); // for debugging
    makeMap(data);
  },
  error: function(data) {
    console.log('it did not work.');
    console.log(data.responseText); 
  }
});
function makeMap(theData) {
    var map = AmCharts.makeChart("mapdiv", {
    type: "map",
    /* DON'T NEED THIS ANYMORE:  
      "dataLoader": {
      "url": "maparticlesfeed.json.php",
      "format":"json",
      "showErrors": false
    },*/
    // replace instead with this:
    "dataProvider" : theData,
    // ... the rest of the map config ...
    }
});

And, in maparticlesfeed.json.php:

<?php 
include('database-connect.php'); 
$con=Database::connect();

if(!empty($_POST) && isset($_POST['reportIdFromPost']) ) { 
    $postedReportId= $_POST['reportIdFromPost']; 
}

include('database-connect.php'); 
$con=Database::connect();
$query=$con->prepare("SELECT * from articles Where reportId=$postedReportId ");
$query->execute();
$articlesList=$query->fetchall(PDO::FETCH_ASSOC);
?>

{
"map" : "MyMapName",
"areas" : [
       // Code to json_encode the results from $articlesList
    ]   
}

Answer 2

It may be that you're posting json data and then not decoding it when you're trying to use the value in your php script.

Try this at the top of maparticlesfeed.json.php:

<?php
include('database-connect.php');

$postedValues = json_decode($POST['reportIdFromPost'], true);

$con=Database::connect();
$query=$con->prepare("SELECT * from articles Where reportId=$postedValues['reportIdFromPost']");
$query=>execute();
$articlesList=$query->fetchall(PDO::FETCH_ASSOC);
?>

You'll also need to uncomment the two lines in the map config:

"type" : "post",
"data" : {"reportIdFromPost" : 1}

Answer 3

Maybe you could add the parameters in the "url" parameter of the dataloader.

"url": "urlA.do?param1=" + $('.selector').val()

and then in some trigger (ie. button click) modify the url and reload

var url = "same URL with different parameters values";
chart.dataLoader.url = url;
chart.dataLoader.loadData()