Need help with warning map. PHP

[davefootball123]

Hi everyone. I'm coding an Environment Canada weather warning map for better ease of use for people. What I need is hopefully simple. On the EC website if a warning is issued a text bulliten for the forecast page will say SEVERE THUNDERSTORM WARNING or any type of warning for that matter. Here is an example of the page http://www.weatheroffice.gc.ca/city/pages/on-94_metric_e.html , if a severe thunderstorm warning is issued at the top of the page it will say SEVERE THUNDERSTORM WARNING IN EFFECT, or TORNADO WARNING IN EFFECT for a tornado warning. What I need to do is have a php code check that url and see if SEVERE THUNDERSTORM WARNING exists and it if does show an image...just a normal <img src="file name"> image.

I hope i explained it clear enough. I think what I need is for php to read the content of an external url and if the required content exists...show the image...if not dont show the image. If anyone could help me that would be greatly appreciated. Thanks, Dave

[xyph]

What have you tried so far?

[davefootball123]

I haven't tried very much, except get_file_contents...and then the url. I think thats how I need to go but I have no clue how to make it look for a piece of text...and if that piece of text is there...show an image.

[Jessica]

for the text you could use strpos

[davefootball123]

Thanks very much. I'm probably sounding rude here but can anyone put some code together... that would read content from a url and then if the defined text is found show an image...of someone could do that...that would be greatly appreciated then I could do it all from there.

 

Thanks, Dave

[Jessica]

You could do all what? That's the whole project minus one if construct. :-P

 

Edit: Wait no, that is the whole project.

[davefootball123]

Lol true...im just new to PHP and trying to make a better weather warning map than what our weather agency is currently using. I'm not sure how much code it would take though..

[Jessica]

$url = '';
$search_string = 'WARNING IN EFFECT';
$file_contents = file_get_contents($url);
if(stripos($file_contents, $search_string) !== FALSE){
// There's a warning.
}

[davefootball123]

Wow, thats so much. Another quick question. What code would display <img src="filenamegoeshere">

 

Thanks so much for the help. It is greatly appreciated.

[Jessica]

The code you just posted. It's HTML. PHP can output HTML using echo or print.

[davefootball123]

<?php

$url = 'http://www.southernontariochasing.ca/testwarn.html';

$search_string = 'SEVERE THUNDERSTORM WARNING IN EFFECT';

$file_contents = file_get_contents($url);

if(stripos($file_contents, $search_string) !== FALSE){

// There's a warning.

echo '<img src="Day 1 Cat.png" />';

}

?>

 

Works great. Thanks!

If I have another issue I will be sure to come back. You guys are great!

[davefootball123]

To follow up to my last post...heres a quick example of what im doing http://www.southernontariochasing.ca/test.php

 

Works wonderful. Thank you.

 

EDIT: One other quick thing. the website that is being read displays the data as <a herf="link>SEVERE THUNDERSTORM WARNING</a> and I have to put that full html code in the seach_string...works fine however the link changes with the issuance of each weather warning. Is there anyway to get around that?

 

Sorry to edit again. I have seem'd to figure it out. Thanks for all the help!

[davefootball123]

I've run into some trouble. Is there a way to have multiple $search_strings...What I mean is it has to meet like SEVERE THUNDERSTORM WATCH and then like the city ie WINDSOR...how would I do this?

[Christian F.]

I think this page will be a good starting point for you, especially if you read the user notes as well. I also recommend reading some tutorials on how to write PHP, the one in the PHP manual is a good start.

Programming is pure logic, after all. So if you've done something that works before, and want to do something just a bit differently, chances are you just have to change the part that's different.

[Drongo_III]

Does the site you're scraping have an RSS feed for weather warnings?

 

That would provide you with a much more robust way of outputting multiple weather warnings...

[davefootball123]

Yes it does, however its an RSS feed for each warning region. Would it still work?

[davefootball123]

One other thing. How could I replace file_get_contents with cUrl?

[Christian F.]

The PHP manual has some very good examples on how to use cURL, along with all of the information you'd ever need about the library. Read it, try for yourself, and come back (with code and a detailed description) if you have problems.

[davefootball123]

OK, thanks Christian

[davefootball123]

OK, I've done a little bit of work, however I continue to have some issues. I believe I changed to cURL properly...however I think strpos is having some trouble reading $search_string because when the condition is met...the overlay doesnt show up. When I set the ! == TRUE...the overlays will always show up. If i set it to false the overlays never show up even when they should.

Here is the code

<?php
$url = 'http://www.weatheroffice.gc.ca/city/pages/on-147_metric_e.html';
function curl_get_contents($url) {
// Initiate the curl session
$ch = curl_init('http://www.weatheroffice.gc.ca/city/pages/on-147_metric_e.html');
// Set the URL<span id="more-487"></span>
curl_setopt($ch, CURLOPT_URL, $url);
// Removes the headers from the output
curl_setopt($ch, CURLOPT_HEADER, 0);
// Return the output instead of displaying it directly
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
// Execute the curl session
$output = curl_exec($ch);
// Close the curl session
curl_close($ch);
// Return the output as a variable
return $output;
}

$output = curl_get_contents('http://www.weatheroffice.gc.ca/city/pages/on-147_metric_e.html');
$search_string = 'SEVERE THUNDERSTORM WATCH IN EFFECT</a>';


if(strpos($output, $search_string) !== false){
// There's a watch.
echo '<center><img style="position:absolute;left:50%;margin-left:-397px; margin-top:30px" src="/Warningoverlays/SVR 

Watch/windsor.png" border="0">';
}

?>

[Christian F.]

Try to add echo '<pre>';var_dump ($output);die (); after your call to curl_get_contents (), and see what you get.

[davefootball123]

It shows the whole webpage on my page...without any CSS of course. I need it to grab that data but only look for 1 thing...the $search_string variable.

[Christian F.]

OK, at least we know that the cURL request works. Now you only need to figure out why the strpos () call fails. I suspect it has something to do with the </a> at the end of the search string.

[davefootball123]

I will try a few things to see if it helps. I will report back in a minute.

 

OK, I tried the full link, didnt work, tried no link and just text didnt work. Still shows the full web page.

[Christian F.]

Ah, yeah... The snippet with var_dump () I gave above was just to debug the process, to check that the cURL request was working. You can delete it now.