IMO this example would have been better if it had done a check for curl_error(), in order to advertize the existence of this function to people learning about cURL who try the example but mysteriously get no response back for whatever reason.
Once you've compiled PHP with cURL support, you can begin using the cURL functions. The basic idea behind the cURL functions is that you initialize a cURL session using the curl_init(), then you can set all your options for the transfer via the curl_setopt(), then you can execute the session with the curl_exec() and then you finish off your session using the curl_close(). Here is an example that uses the cURL functions to fetch the example.com homepage into a file:
Example #1 Using PHP's cURL module to fetch the example.com homepage
<?php
$ch = curl_init("http://www.example.com/");
$fp = fopen("example_homepage.txt", "w");
curl_setopt($ch, CURLOPT_FILE, $fp);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_exec($ch);
curl_close($ch);
fclose($fp);
?>
IMO this example would have been better if it had done a check for curl_error(), in order to advertize the existence of this function to people learning about cURL who try the example but mysteriously get no response back for whatever reason.
It is important to notice that when using curl to post form data and you use an array for CURLOPT_POSTFIELDS option, the post will be in multipart format
<?php
$params=['name'=>'John', 'surname'=>'Doe', 'age'=>36)
$defaults = array(
CURLOPT_URL => 'http://myremoteservice/',
CURLOPT_POST => true,
CURLOPT_POSTFIELDS => $params,
);
$ch = curl_init();
curl_setopt_array($ch, ($options + $defaults));
?>
This produce the following post header:
--------------------------fd1c4191862e3566
Content-Disposition: form-data; name="name"
Jhon
--------------------------fd1c4191862e3566
Content-Disposition: form-data; name="surnname"
Doe
--------------------------fd1c4191862e3566
Content-Disposition: form-data; name="age"
36
--------------------------fd1c4191862e3566--
Setting CURLOPT_POSTFIELDS as follow produce a standard post header
CURLOPT_POSTFIELDS => http_build_query($params),
Which is:
name=John&surname=Doe&age=36
This caused me 2 days of debug while interacting with a java service which was sensible to this difference, while the equivalent one in php got both format without problem.
Using ArangoDB with PHP
Coding with a NoSQL data base like ArangoDB can be made more complicated then need be. A simple solution to code for ArangoDB is to use the REST interface directly.
All you need is a few initialization variables and a small function to ease the typing - and of cause install the php5-curls module...
See ArangoDB REST API documentation for options and request types.
<?php
// Initialize options for REST interface
$adb_url="http://127.0.0.1:8529";
$adb_option_defaults = array(
CURLOPT_HEADER => false,
CURLOPT_RETURNTRANSFER => true,
CURLOPT_TIMEOUT => 2
);
// ArangoDB REST function.
// Connection are created demand and closed by PHP on exit.
function adb_rest($method,$uri,$querry=NULL,$json=NULL,$options=NULL){
global $adb_url,$adb_handle,$adb_option_defaults;
// Connect
if(!isset($adb_handle)) $adb_handle = curl_init();
echo "DB operation: $method $uri $querry $json\n";
// Compose querry
$options = array(
CURLOPT_URL => $adb_url.$uri."?".$querry,
CURLOPT_CUSTOMREQUEST => $method, // GET POST PUT PATCH DELETE HEAD OPTIONS
CURLOPT_POSTFIELDS => $json,
);
curl_setopt_array($adb_handle,($options + $adb_option_defaults));
// send request and wait for responce
$responce = json_decode(curl_exec($adb_handle),true);
echo "Responce from DB: \n";
print_r($responce);
return($responce);
}
?>
Here's some examples:
<?php
// Create a collection
$responce = adb_rest("POST","/_api/collection","",'{"name" : "test"}');
// Create a document
$responce = adb_rest("POST","/_api/document","collection=test",'{ "hello" : "World" }');
// List documents in a collection
$responce=adb_rest("GET","/_api/document","collection=test");
// Change document
$document_handle=$responce['documents'][0];
$responce=adb_rest("PATCH",$document_handle,"",'{ "hello" : "World of mine" }');
// Show document
$responce=adb_rest("GET",$document_handle);
// Search
$responce=adb_rest("POST","/_api/cursor","",'{
"query" : "FOR t IN test RETURN t",
"count" : true,
"batchSize" : 50
}');
while($responce['hasMore'])
$responce=adb_rest("PUT","/_api/cursor/".$responce['id']);
// Delete document
$responce=adb_rest("DELETE",$document_handle);
// DB Delete collection
$responce=adb_rest("DELETE","/_api/collection/test");
// to handle errors, add something like this:
if($responce['error']) die ("can't create collection");
?>
The example fetches a resource (the homepage of a website) and writes it to the the file represented by $fp.
Judging from comments elsewhere in this chapter, the example given ought to set CURLOPT_RETURNTRANSFER to true prior to setting CURLOPT_FILE.