Difference between revisions of "LlHTTPRequest"
Reno Parkin (talk | contribs) m |
|||
| Line 18: | Line 18: | ||
|caveats= | |caveats= | ||
*If there is a space in '''url''', the [[http_response]] status code will be 499. | *If there is a space in '''url''', the [[http_response]] status code will be 499. | ||
*The corresponding [[http_response]] event will be triggered in all scripts in the [[prim]], not just in the requesting script. | *The corresponding [[http_response]] event will be triggered in all scripts in the [[prim]], not just in the requesting script. (This appears to have changed in Server 11.10.21.243634 and now only the originating script gets the event.) | ||
*Requests must fully complete after 60 seconds, or else the response will be thrown away and the [[http_response]] status code will be 499. | *Requests must fully complete after 60 seconds, or else the response will be thrown away and the [[http_response]] status code will be 499. | ||
*The response body is limited to 2048 bytes; if it is longer it will be truncated. | *The response body is limited to 2048 bytes; if it is longer it will be truncated. | ||
Revision as of 13:03, 8 November 2011
| LSL Portal | Functions | Events | Types | Operators | Constants | Flow Control | Script Library | Categorized Library | Tutorials |
Summary
Function: key llHTTPRequest( string url, list parameters, string body );| 0.0 | Forced Delay |
| 10.0 | Energy |
Sends an HTTP request to the specified URL with the body of the request and parameters.
Returns a key that is a handle identifying the HTTP request made.
| • string | url | – | A valid HTTP/HTTPS URL. | |
| • list | parameters | – | configuration parameters, specified as HTTP_* flag-value pairs
[ parameter1, value1, parameter2, value2, . . . parameterN, valueN] |
|
| • string | body | – | Contents of the request. |
| Flag | Parameter(s) | Default Parameter Value(s) | Description | |||||
|---|---|---|---|---|---|---|---|---|
| HTTP_METHOD | 0 | [string method] | ["GET"] | "GET", "POST", "PUT" and "DELETE" | ||||
| HTTP_MIMETYPE | 1 | [string MIME_type] | ["text/plain;charset=utf-8"] | text/* MIME types should specify a charset. To emulate HTML forms use application/x-www-form-urlencoded. This allows you to set the body to a properly escaped (llEscapeURL) sequence of <name,value> pairs in the form var=value&var2=value2 and have them automatically parsed by web frameworks.
| ||||
| HTTP_BODY_MAXLENGTH | 2 | [integer length] | [2048] | Sets the maximum (UTF-8 encoded) byte length of the HTTP response body. The maximum that can be set depends upon which VM is used.
| ||||
| HTTP_VERIFY_CERT | 3 | [integer verify] | [TRUE] | If TRUE, the server SSL certificate must be verifiable using one of the standard certificate authorities[1] when making HTTPS requests. If FALSE, any server SSL certificate will be accepted. | ||||
| HTTP_VERBOSE_THROTTLE | 4 | [integer noisy] | [TRUE] | If TRUE, shout error messages to DEBUG_CHANNEL if the outgoing request rate exceeds the server limit. If FALSE, the error messages are suppressed (llHTTPRequest will still return NULL_KEY). | ||||
| HTTP_CUSTOM_HEADER | 5 | [string name, string value] | NA | Add an extra custom HTTP header to the request. The first string is the name of the parameter to change, e.g. "Pragma", and the second string is the value, e.g. "no-cache". Multiple custom headers may be configured per request, as long as the combined custom header length is no greater than 4096 characters. Note that certain headers, such as the default headers, are blocked for security reasons. | ||||
| HTTP_PRAGMA_NO_CACHE | 6 | [integer send_header] | [TRUE] | Sends "Pragma: no-cache" header (TRUE), or does not send a "Pragma" header (FALSE). | ||||
| HTTP_USER_AGENT | 7 | [string user agent value] | [(none)] | The user agent value is appended to the one generated by LSL itself. It should follow the syntax from the HTTP standard like: "My-Script-Name/1.0 (Mozilla compatible)".
Note: Spaces are not allowed in HTTP User Agent token values, so "My Script Name/1.0" will produce a script error; change the spaces to hyphens ("-") | ||||
| HTTP_ACCEPT | 8 | [string MIME_type] | ["text/plain;charset=utf-8"] | HTTP_ACCEPT parameters can be passed to limit the number of mime types that are sent in the Accept: header of the HTTP request. Specified mime types may include character set and q parameters. This parameter may be specified multiple times.
The specified mime type must be one already recognized by llHTTPRequest. These include any text/ mime type, or the following application mime types: “application/xhtml+xml”, “application/atom+xml”, “application/json”, “application/xml”, “application/llsd+xml”, “application/x-javascript”, “application/javascript”, “application/x-www-form-urlencoded”, or “application/rss+xml”. The Content-Type header in the response is checked against the specified HTTP_ACCEPT parameters. If the value of the header is not in the list of acceptable mime types, llHTTPRequest will return 415 as a result code and the body will be "Unsupported or unknown Content-Type." | ||||
| HTTP_EXTENDED_ERROR | 9 | [integer extended] | [FALSE] | If TRUE llHTTPRequest will always return a key. If there was an error making the HTTP request. Detailed error information will be returned through the http_response event using the provided key. Error information is delivered in a JSON block as described in RFC 7807. Details about extended return codes can be found below. |
| Header | Description | Example data |
|---|---|---|
| Connection | Connection options | close |
| Cache-Control | Maximum response age accepted. | max-age=259200 |
| X-Forwarded-For | Used to show the IP address connected to through proxies. | 127.0.0.1 |
| Via | Shows the recipients and protocols used between the User Agent and the server. | 1.1 sim10115.agni.lindenlab.com:3128 (squid/2.7.STABLE9) |
| Content-Length | The size of the entity-body, in decimal number of octets. | 17 |
| Pragma | The message should be forwarded to the server, even if it has a cached version of the data. | no-cache |
| X-SecondLife-Shard | The environment the object is in. "Production" is the main grid and "Testing" is the preview grid | Production |
| X-SecondLife-Region | The name of the region the object is in, along with the global coordinates of the region's south-west corner | Jin Ho (264448, 233984) |
| X-SecondLife-Owner-Name | Legacy name of the owner of the object | Zeb Wyler |
| X-SecondLife-Owner-Key | UUID of the owner of the object | 01234567-89ab-cdef-0123-456789abcdef |
| X-SecondLife-Object-Name | The name of the object containing the script | Object |
| X-SecondLife-Object-Key | The key of the object containing the script | 01234567-89ab-cdef-0123-456789abcdef |
| X-SecondLife-Local-Velocity | The velocity of the object | 0.000000, 0.000000, 0.000000 |
| X-SecondLife-Local-Rotation | The rotation of the object containing the script | 0.000000, 0.000000, 0.000000, 1.000000 |
| X-SecondLife-Local-Position | The position of the object within the region | (173.009827, 75.551231, 60.950001) |
| User-Agent | The user-agent header sent by LSL Scripts. Contains Server version. | Second Life LSL/16.05.24.315768 (http://secondlife.com) |
| Content-Type | The media type of the entity body. | text/plain; charset=utf-8 |
| Accept-Charset | Acceptable character sets from the server. Q being the quality expected when sending the different character sets. | utf-8;q=1.0, *;q=0.5 |
| Accept | Media types the server will accept. | text/*, application/xhtml+xml, application/atom+xml, application/json, application/xml, application/llsd+xml, application/x-javascript, application/javascript, application/x-www-form-urlencoded, application/rss+xml |
| Accept-Encoding | Acceptable content encodings for the server. | deflate, gzip |
| Host | The internet host being requested. | secondlife.com |
|
||
Caveats
- If there is a space in url, the http_response status code will be 499.
- The corresponding http_response event will be triggered in all scripts in the prim, not just in the requesting script. (This appears to have changed in Server 11.10.21.243634 and now only the originating script gets the event.)
- Requests must fully complete after 60 seconds, or else the response will be thrown away and the http_response status code will be 499.
- The response body is limited to 2048 bytes; if it is longer it will be truncated.
- Requests are throttled on a per object basis (not per prim).
- Requests are throttled to a maximum of 25 requests per 20 seconds. This is to support a sustained rate of 1 per second or a burst of up to 25.
- NULL_KEY is returned if the request is throttled.
- See this thread and this thread for more details.
- Cannot be used to load textures or images from the internet, for more information see Web Textures.
- If the accessed site is relying on the LSL script to report L$ transactions, then it must check the X-SecondLife-Shard header to see if the script is running on the beta grid.
- Some servers will return a 405 error if you send POST to a file that can't accept metadata, such as a text or HTML file. Make sure you use the GET method to ensure success in any environment.
- While the HTTP status code from the server is provided to the script, redirect codes such as 302 will result in the redirect being automatically and transparently followed ONLY IF the HTTP_METHOD is GET, with the resulting response being returned. If the HTTP_METHOD is anything other then GET then you'll get back an http_response with a status code of 302, but without any way to view the headers, you can't know where you were being redirected to unless that was also included in the body.
- The following applies when making a request to a script using HTTP-In:
- When appending a query string to a cap URL there MUST be a trailing slash between the cap guid and the query string token '?'. IE https://sim123.agni.lindenlab.com/cap/f23b4b94-012d-44f2-bd0c-16c328321221?arg=gra will return an HTTP 500, but https://sim123.agni.lindenlab.com/cap/f23b4b94-012d-44f2-bd0c-16c328321221/?arg=gra will succeed.
- X-SecondLife-Owner-Name may return "(Loading...)" instead of owner name (still true, 18th of July, 2011)
- Requests made at approx 0625 SLT may fail with a 503 status code, with "ERROR: The requested URL could not be retrieved", and "(111) Connection refused" in the body of the response. This has been confirmed as expected behaviour by Kelly, due to the nightly maint & log rotation. It does reliably impact object to object HTTP at that time, and quite probably may impact object to/from web around the same time. The interruption in service is fairly brief, and the precise timing may vary as LL adjust their nightly maint processes, or due to server load.
Examples
<lsl>key http_request_id;
default {
state_entry()
{
http_request_id = llHTTPRequest("url", [], "");
}
http_response(key request_id, integer status, list metadata, string body)
{
if (request_id == http_request_id)
{
llSetText(body, <0,0,1>, 1);
}
}
}</lsl>
Example PHP test script: <php><?php header("content-type: text/plain; charset=utf-8"); ?> Headers received: <?php
/**
* @author Wouter Hobble * @copyright 2008 */
foreach ($_SERVER as $k => $v) { if( substr($k, 0, 5) == 'HTTP_') { print "\n". $k. "\t". $v; } } ?></php>
example wrapper script Both capturing apache headers and global methodes <php> <?PHP // Author Waster Skronski. // General Public License (GPL). // Mind that some headers are not included because they're either useless or unreliable. $USE_APACHE_HEADERS = TRUE; // switch to false if you need cgi methods if ($USE_APACHE_HEADERS) { $headers = apache_request_headers(); $objectgrid = $headers["X-SecondLife-Shard"]; $objectname = $headers["X-SecondLife-Object-Name"]; $objectkey = $headers["X-SecondLife-Object-Key"]; $objectpos = $headers["X-SecondLife-Local-Position"]; $ownerkey = $headers["X-SecondLife-Owner-Key"]; $ownername = $headers["X-SecondLife-Owner-Name"]; $regiondata = $headers["X-SecondLife-Region"]; $regiontmp = explode ("(",$regiondata); // cut cords off $regionpos = explode (")",$regiontmp[1]); // $regionname = substr($regiontmp[0],0,-1); // cut last space from simname } else { $db = $GLOBALS; $headers = $db['HTTP_ENV_VARS']; $objectgrid = $headers["HTTP_X_SECONDLIFE_SHARD"]; $objectname = $headers["HTTP_X_SECONDLIFE_OBJECT_NAME"]; $objectkey = $headers["HTTP_X_SECONDLIFE_OBJECT_KEY"]; $ownerkey = $headers["HTTP_X_SECONDLIFE_OWNER_KEY"]; $objectpos = $headers["HTTP_X_SECONDLIFE_LOCAL_POSITION"]; $ownername = $headers["HTTP_X_SECONDLIFE_OWNER_NAME"]; $regiondata = $headers["HTTP_X_SECONDLIFE_REGION"]; $regiontmp = explode ("(",$regiondata); $regionpos = explode (")",$regiontmp[1]); $regionname = substr($regiontmp[0],0,-1); } ?> </php>
Notes
If for some reason while using llHTTPRequest/http_response you are unable to parse a known good RSS feed or some other form of web contents, you will need to work around it outside of SecondLife. This is unlikely to change in the near future since checking the headers requires more overhead at the simulator level.
You may find that some web servers return either a null or a nonsensical result when llHTTPRequest is used, even though the same URL in a PC web browser returns the expected result. This may be due to the fact that the llHTTPRequest User Agent string is not recognised by some web servers as it does not contain "Mozilla", which would identify it as a web browser instead of, for example, a Shoutcast or an RSS client. A workaround is to append " HTTP/1.0\nUser-Agent: LSL Script (Mozilla Compatible)\n\n" or similar to the URL string, which will kludge the HTTP request to look like it originates from a web browser. This is also true when the PHP relays on $_COOKIE. LSL http request can neither set cookie nor retrieve them.
CGI environments may place the headers into variables by capitalizing the entire name, replacing dashes with underscores, and prefixing the name with "HTTP_", e.g. "HTTP_X_SECONDLIFE_OBJECT_NAME". PHP $_SERVER variables do this as well.
Apache can include the headers in its logs, using the CustomLog and LogFormat directives. See the docs for details on the syntax.