Recover distance with Google Map API

[georgie]

Hello

I would do a kind of Ubber App with Fabrik. I try the "Direction" option in Map Viz, nice!
I would recover distance between my 2 point according Google Map, please is it possible?
Have you some documentation about this?

THX

 

[cheesegrits]

I've never tried it, but I'm sure it's possible.

What exactly are you trying to do? Do you want this in JavaScript? Where would you display it?

-- hugh

 

[georgie]

Yes in Javascript I think, in a PHP plugin form for example, to recover the value in a field.

Indeed after, I would do a calculation with the distance, to display a "Estimated price".

You think to anything?

 

[georgie]

Hello

It going...
For now, by GM API, I can create an URL in a Fabrik form plugin, URL that leads to a dynamic JSON, with correct distance and time according Google, greats!

I use for that two Fabrik GM elements, from which I remove parentheses and zoom, and replace spaces by "%20".
Then I put them in the GM URL to ask distance. It works fine, and it corresponds to the map provided by the Fabrik Direction option!
Here my code in a PHP Fabrik form plugin (with a var_dump at end):

// Clean Start GM element
$VarStart =  '{booking___start_address_coord}' ;
$MaVarStart2 =  substr($VarStart, 0, strpos($VarStart, ":"));
$MaVarStart3 = str_replace('(' , '' , $MaVarStart2) ;
$MaVarStart4 = str_replace(')' , '' , $MaVarStart3) ;
$MaVarStart5 = str_replace(' ' , '%20' , $MaVarStart4) ;
$VarStart= $MaVarStart5 ;

// Clean End GM element
$VarArrival =  '{booking___end_address_coord}' ;
$MaVarArrival2 =  substr($VarArrival, 0, strpos($VarArrival, ":"));
$MaVarArrival3 = str_replace('(' , '' , $MaVarArrival2) ;
$MaVarArrival4 = str_replace(')' , '' , $MaVarArrival3) ;
$MaVarArrival5 = str_replace(' ' , '%20' , $MaVarArrival4) ;
$VarArrival= $MaVarArrival5 ;

// Create URL according GM API
$VarURLGM = "https://maps.googleapis.com/maps/api/distancematrix/json?origins=$MaVarStart5&destinations=$MaVarArrival5" ;

// Read the JSON
//$obj = json_decode("$VarURLGM") ;

// Look up var
var_dump((string) $VarURLGM) ;
exit ;

And here an example to a dynamic JSON URL created:
https://maps.googleapis.com/maps/ap...2&destinations=49.0449034, 2.0419157999999697

But now I am blocked, indeed I can not read variables from this JSON in my var_dump.
I have tried some syntaxs with "json_decode" and "file_get_contents", without success...

Please can you help me?

 

[cheesegrits]

Good work.

I think the you'll need to get a key, and append it to your API call:

https://developers.google.com/maps/documentation/distance-matrix/get-api-key

To avoid excessive use of the API, the best place to do this would be when submitting the form, in a PHP plugin onBeforeProcess, and set the form data for the distance.

To get the coords, there's a helper, FabrikString::mpStrToCoords() ...

// get the simple "lat,long" strings
$coords = FabrikString::mapStrToCoords('{booking___start_address_coord}') ;
$startCoords= $coords->lat . ',' . $coords->long;
$coords = FabrikString::mapStrToCoords('{booking___end_address_coord}') ;
$endCoords = $coords->lat . ',' . $coords->long;

//build the URL, with API key
$distanceURL = "https://maps.googleapis.com/maps/api/distancematrix/json?origins=$startCoords&destinations=$endCoords&key=xxxxxxxxxxxxxxx" ;

// get the result and decode it
$distanceData = file_get_contents($distanceURL);
$distanceResult = json_decode($distanceData);

// test ... comment this out once you have the right URL and are getting sane JSON
var_dump($distanceURL, $distanceResult); exit;

// if result OK, grab the 'value' from the first row's first element data and stuff it into your distance element
if ($distanceResult->status === 'OK') {
   $firstRow = FArrayHelper::getValue($distanceResults->rows, 0);
   $firstElement = FArrayHelper::getValue($firstRow, 0);
   $formModel->setFormData('booking___distance', $firstElement->distance->value);
}

I haven't tried that code, so I can't guarrantee it, but looking at the JSON example you gave, it should be right.

-- hugh

 

[cheesegrits]

Oh, also, make sure your PHP ini has 'allow_fopen_url' set to Yes (or 1), so that file_get_contents() will work.

-- hugh

 

[georgie]

Hello

Thanks for "FabrikString::mapStrToCoords" , more short...

Indeed, with the "get the result and decode it" method, I can read the JSON, thanks

But I can not select row and value, this code for example (var_dump at end) gives no error but just "NULL":

// get the simple "lat,long" strings
$coords = FabrikString::mapStrToCoords('{booking___start_address_coord}') ;
$startCoords= $coords->lat . ',' . $coords->long;
$coords = FabrikString::mapStrToCoords('{booking___end_address_coord}') ;
$endCoords = $coords->lat . ',' . $coords->long;

//build the URL, with API key
$distanceURL = "https://maps.googleapis.com/maps/api/distancematrix/json?origins=$startCoords&destinations=$endCoords&key=MYKEY" ;

// get the result and decode it
$distanceData = file_get_contents($distanceURL);
$distanceResult = json_decode($distanceData);

$firstRow = FArrayHelper::getValue($distanceResults->rows,0);
$firstElement = FArrayHelper::getValue($firstRow,0);

// Test ... comment this out once you have the right URL and are getting sane JSON
var_dump($firstElement ); exit;

Please what do you think about?

 

[troester]

I don't know exactly what FArrayHelper is doing.
Maybe FArrayHelper::getValue($firstRow->elements,0); is doing.

"Manually" with var_dump($distanceResult->rows[0]->elements[0]); I see
object(stdClass)#3 (3) {
["distance"]=>
object(stdClass)#4 (2) {
["text"]=>
string(6) "4.8 km"
["value"]=>
int(4842)
}
["duration"]=>
object(stdClass)#5 (2) {
["text"]=>
string(7) "11 mins"
["value"]=>
int(673)
}
["status"]=>
string(2) "OK"
}

 

[georgie]

Thanks!
"Manually" it seems to work. You do not advice to do like this in PHP form plugin?
Because it seems to work without "FArrayHelper", just with "$distanceResult->rows[0]->elements[0]->distance->value".
I keep my tests.

 

[cheesegrits]

You should still use the array helper, in case you don't get a result from Google, in which case just trying to blindly access [0] will error out. The array helper (which is actually the Joomla JArrayHelper, with a few extra function) getValue() will prevent getting an error trying to access a non-existant array index. The way you use it is ...

$whatever = FArrayHelper($yourArray, $yourIndex, $yourDefault);

... so if $yourIndex doesn't exist in $yourArray, you get back $yourDefault instead of a PHP error / warning and a null result.

You also need to test for "OK" in the status.

The reason it's NULL is because I made a typo. Look at the code, and you'll see I assigned $distanceResult, then used $distanceResults (plural) in the array helper.

if ($distanceResult->status === 'OK') {
   // get the first row, by using the array helper to get index 0, with an empty array as default
   $firstRow = FArrayHelper::getValue($distanceResult->rows, 0, array());
   // check to see if the result is empty
   if (!empty($firstRow)) {
      // if we got the first row, get the first element from it
      $firstElement = FArrayHelper::getValue($firstRow, 0);
      if (!empty($firstElement)) {
         // if we got the element, get the distance
         $formModel->setFormData('booking___distance', $firstElement->distance->value);
      }
   }
}

 

[cheesegrits]

At some point I might add this functionality to the map element, and let you designate a 'distance' element in with the rest of the geocode settings. It's something I did think of doing when I added the Directions from feature, I just haven't had time to do it.

-- hugh