General Support: Images on a Map

I too am interested in this. I've been carrying a GPS with me for years when taking photos, but haven't really made any practical use of it.

I've written a Javascript GPX viewer using google maps (http://notions.okuda.ca/geotagging/projects-im-working-on/gpx-viewer/), I'm writing my own geotagger in C# that uses Google Maps (http://code.google.com/p/geotagger/), and some code for my previous gallery (mg2) to read the GPS data from photos (http://notions.okuda.ca/mg2-hacks/exif-parser/), but have never got around to putting any of these things together.

It would be very easy to add a couple of fields for the coordinates of photos that could either be extracted from the images when they are uploaded (using the php exif library) , or edited in the admin interface. It would be easy to get the coordinates from clicking on a Google Map (see my geotagger project, as it uses a Javascript interface with Google Maps for that purpose, with dragging and dropping markers).

Once you have the data in the database, then getting it out in a readable format should be straight forward. A list of photos and coordinates, either XML (GPX?), JSON, or some other format, should be easy to parse and display in a Google Map (see my GPX viewer).

I would be interested in helping out with this (when I have the time) or feel free to use the code I've published around this to make it happen. I would love to see it happen.

KOkuda,

If you are still around I am dying to know how you did http://okuda.ca/gallery/index.php?id=70 on your site with the link to the google maps on the GPS section. I have been working for about a week now trying to do exactly that. My problem is on plogger when I get to the picture view that displays all the field (same place your picture is at in the above link), I can not tell plogger to send that pictures Lat Long to google maps to link me to the location. If you are around and can help send me an email at mstreubert AT hotmail dot com

EDIT: TO be more specific I need to know how to put the below into the exif picture.php

function MakeMapURL($exif)
{
if (isset($exif['GPSVersion']))
{
echo "<a href=\"http://maps.google.com/maps?q=";
echo $exif['GPSLatitudeRef'];
echo $exif['GPSLatitude'];
echo ",+";
echo $exif['GPSLongitudeRef' ];
echo $exif['GPSLongitude'];
echo "&spn=0.0,0.0&t=h&hl=en\" target=\"_blank\">View location in Google Maps</a>";
}
}


I have made mine to represent my fields in my DB so the naming is changed a bit

function MakeMapURL($exif)
{
if (isset($exif['GPSVersion']))
{
echo "<a href=\"http://maps.google.com/maps?q=";
echo $exif['EXIF_lat_ref'];
echo $exif['EXIF_lat'];
echo ",+";
echo $exif['EXIF_long_ref' ];
echo $exif['EXIF_long'];
echo "&spn=0.0,0.0&t=h&hl=en\" target=\"_blank\">View location in Google Maps</a>";
}
}



I think I have to change if (isset($exif['GPSVersion'])) but I do not know what it is : P Is GPSVerision your field on your details? So for plogger I need to put this function in plog-functions, but again I do not know exactly where and I do not know how to use the GPSVersion. Most of my photos have Lat Long.

Also I am hoping that plogger will allow this function to reside in plog-functions.php as well I need to figure out how to fit the new field which you are linking to google maps into the function generate_exif_table, as that is where I want the hyperlink to be displayed.

I am testing in the exif table like this

<tr>
<td><strong>GPS</strong></td>
<td><? echo MakeMapURL($exif_data) ?></td>
</tr>

but that is not working... because I do not know how to tell it how to populate the field with the result of the function


Thanks

Sid,

Thanks for the advice on creating my own functions. I have done so now the problem I have run into is incorporating the result of that function into the table

$table_data = '<div id="exif_table">';
$table_data .= '
<table id="exif_data_visible">
<tr>
<td><strong>GPS</strong></td>
<td><MakeMapURL($exif_data)></td>
</tr>
<tr>
<td><strong>Subject</strong></td>
<td>'.$row["EXIF_subj_ref"].'</td>
</tr>
<tr>
<td><strong>Date/Time</strong></td>
<td>'.$row["EXIF_date_time_orig"].'</td>
</tr>
<tr>
<td><strong>Latitude</strong></td>
<td>'.$row["EXIF_lat"].' '.$row["EXIF_lat_ref"].'</td>
</tr>
<tr>
<td><strong>Longitude</strong></td>
<td>'.$row["EXIF_long"].' '.$row["EXIF_long_ref"].'</td>
</tr>
</table>';

If you recall that is the table you helped me make for my visible exif data. In its current form the GPS html will not display. Any thoughts on how to make that link display on my picture.php

<td><? echo "GPS" ?></td>
<td><? echo MakeMapURL($exif_data) ?></td>

was the suggestion on KOkuda's website, but that will not work either.

thanks

function MakeMapURL($exif)
{
if (!empty($exif['EXIF_lat']))
{
echo "<a href=\"http://maps.google.com/maps?q=";
echo $exif['EXIF_lat_ref'];
echo $exif['EXIF_lat'];
echo ",+";
echo $exif['EXIF_long_ref' ];
echo $exif['EXIF_long'];
echo "&spn=0.0,0.0&t=h&hl=en\" target=\"_blank\">View location in Google Maps</a>";
}
}

with that as my function it returns <>

One problem I see is that there is a mixing of styles. Your html is being built as a string in php, while my examples assume that the php is being escaped briefly in the html. You are building a string, so you need to close the string before calling any php functions.

You are starting the string here...
$table_data .= '

So the following will not call any functions, only generate MakeMapURL as part of the html.
<td><MakeMapURL($exif_data)></td>

You need to close the string, call the function, and then open it again. Hence the suggestion of <td><'.MakeMapURL(...).'></td>

However, this assumes that the MakeMapURL function will return a string. I'm not sure if the echo calls within that function will do the trick (it will probably cause the output to be out of order). You should make both parts of the code follow the same format. Either echo each line of output, or generate a single string that you echo at the end.

I suggest you add the '. and .' around the MakeMapURL call and change the function to build and return a string, like you are doing with $table_data.

edit: Sorry, the formatting was all lost as html
edit2: What sidtheduck said.

function generate_exif_table($id, $condensed = 0){
global $config;
$query = "SELECT * FROM `".TABLE_PREFIX."pictures` WHERE `id`=".intval($id);
$result = run_query($query);
if (mysql_num_rows($result) > 0){
$row = mysql_fetch_assoc($result);
foreach($row as $key => $val) if (trim($row[$key]) == '') $row[$key] = '&nbsp;';
$exif_map_link = MakeMapURL($exif_data);
$table_data = '<div id="exif_table">';
$table_data .= '
<table id="exif_data_visible">
<tr>
<td><strong>GPS</strong></td>
<td>'.$exif_map_link.'</td>

with the function

function MakeMapURL($exif)
{
if (!empty($exif['EXIF_lat']))
{
return "<a href=\"http://maps.google.com/maps?q=".$exif['EXIF_lat_ref'].$exif['EXIF_lat'].",+".$exif['EXIF_long_ref' ].$exif['EXIF_long']."&spn=0.0,0.0&t=h&hl=en\" target=\"_blank\">View location in Google Maps</a>";
}
}

Now leaves the area after GPS blank. I dunno why but also tried it with $exif_map_link = MakeMapURL($exif); instead of $exif_data

DOH! You need to do:
$exif_map_link = MakeMapURL($row);

How about this (with single quotes instead of doubles)? It *shouldn't* matter, but maybe it does.
return '<a href="http://maps.google.com/maps?q='.$exif['EXIF_lat_ref'].$exif['EXIF_lat'].',+'.$exif['EXIF_long_ref'].$exif['EXIF_long'].'&spn=0.0,0.0&t=h&hl=en" target="_blank">View location in Google Maps</a>';

UPDATE:

I did this as my work around

function MakeMapURL($exif)
{
if (!empty($exif['EXIF_lat']))
{
$long=substr($exif['EXIF_long'], 0, -1);
$lat=substr($exif['EXIF_lat'], 0, -1);
return "<a href=\"http://maps.google.com/maps?q=".$exif['EXIF_lat_ref'].$lat.",".$exif['EXIF_long_ref' ].$long."&spn=0.0.,.0.0&t=h&hl=en\" target=\"_blank\">View location in Google Maps</a>";
}
}

Basically the " in the database were ending the google map search so I used the substr php to elimate that quotation mark.

Works very good

Final question if anyone can help me with is I would like a better means to stop photo's without the lat and long from having the google map link. I do not want the user to be able to click or see the google map link if no lat exists. How can I do that?