Working with Request
About Request
When route handler (or controller) is executed, dispatcher will
call its handleRequest() and pass request object that contains handful data
related to current request.
This request object is instance of IRequest interface that can be queried for
data such as query strings, cookies, POST data send by client or uploaded files.
Read Working with Controllers for more information on how to work with route handler or controller.
Getting query parameters
If you registered route /home and user open http://[your hostname]/home?msg1=test&msg2=nice
To retrieve value of msg1 and msg2 parameters, you can use getQueryParam()
method.
var msg1, msg2 : string;
...
msg1 := request.getQueryParam('msg1'); //msg1 = 'test'
msg2 := request.getQueryParam('msg2'); //msg2 = 'nice'
To set default value if msg1 is not set,
msg1 := request.getQueryParam('msg1', 'ok');
To retrieve all query parameters at once, use getQueryParams()
var params : IReadOnlyList;
...
params := request.getQueryParams();
Retrieve cookies
To retrieve value of msg1 and msg2 parameters from cookies, you can use getCookieParam() method.
var msg1, msg2 : string;
...
msg1 := request.getCookieParam('msg1');
msg2 := request.getCookieParam('msg2');
To set default value if msg1 cookie is not set,
msg1 := request.getCookieParam('msg1', 'ok');
To retrieve all cookie parameters at once, use getCookieParams()
var cookies : IReadOnlyList;
...
cookies := request.getCookieParams();
Get POST/PUT/PATCH data
If you have form like following snippet
<form action="/submit" method="post">
<input type="text" name="msg1" value="test">
<input type="text" name="msg2" value="nice">
<button type="submit">Submit</button>
</form>
To retrieve value of msg1 and msg2 parameters from POST/PUT/PATCH data, you can use getParsedBodyParam() method.
var msg1, msg2 : string;
...
msg1 := request.getParsedBodyParam('msg1');
msg2 := request.getParsedBodyParam('msg2');
To set default value if msg1 parameter is not set,
msg1 := request.getParsedBodyParam('msg1', 'ok');
To retrieve all POST parameters at once, use getParsedBodyParams()
var params : IReadOnlyList;
...
params := request.getParsedBodyParams();
Get query parameters and POST/PUT/PATCH data
To get query string parameters and POST/PUT/PATCH data as one list
var params : IReadOnlyList;
...
params := request.getParams();
To read single value
msg1 := request.getParam('msg1', 'ok');
Above method search query string parameter first. If it cannot find data with key msg1, it tries to read body parameters. If none found, default value ok is returned.
Read request header
To get request headers, use headers() methods of IRequest. It returns instance of IReadOnlyHeaders interface.
To read request header value, call getHeader() method and pass header to read. For example to read Accept-Language header value,
var acceptLang : string;
...
acceptLang := request.headers().getHeader('Accept-Language');
To test availability of header, call has() method. For example to test if Accept-Language header is set,
var langAvail : boolean;
...
langAvail := request.headers().has('Accept-Language');
Get HTTP method
To get request http method such as GET, POST, etc., use method property.
var httpMethod : string;
...
httpMethod := request.method;
Get request URI
To get request URI, use uri() method. It returns IUri interface which you can use to get information regarding current request URI such as scheme, host, port, path, query string, fragment. Read RFC 3986 for information regarding URI.
var reqUri : IUri;
...
reqUri := request.uri();
//if we have https://example.com:8080/hello?q=good#fano
//print uri scheme i.e, https
writeln(reqUri.scheme);
//print uri host i.e, example.com
writeln(reqUri.host);
//print uri port i.e, 8080
writeln(reqUri.port);
//print uri path i.e, /hello
writeln(reqUri.path);
//print uri query i.e, q=good
writeln(reqUri.query);
//print uri fragment i.e, fano
writeln(reqUri.fragment);
Get current environment variables
You can get current CGI environment using env property.
var reqEnv : ICGIEnvironment;
...
reqEnv := request.env;
Read CGI Environment for more information.
Check if request is AJAX
To test if request is AJAX request, use isXhr() method.
var ajax : boolean;
...
ajax := request.isXhr();
Handling request with JSON body
To handle request with application/json body, such as following shell command
$ curl --header "Content-Type: application/json" \
--request POST \
--data '{"username":"xyz","password":"xyz"}' \
http://yourapp.fano/submit
Fano Framework provides TJsonRequest class which decorates IRequest instance to handle such request. For example, to read username in request above,
var originalRequest, jsonRequest : IRequest;
...
jsonRequest := TJsonRequest.create(originalRequest);
username := jsonRequest.getParsedBodyParam('username');
password := jsonRequest.getParsedBodyParam('password');
For more complex JSON structure, you can read it using its name separated by dot. For JSON data,
{
"username" : "xyz",
"password" : "xyz",
"login" : {
"lastLogin" : "2020-02-10 10:10:00"
}
}
You can read lastLogin data as follows,
lastLogin := jsonRequest.getParsedBodyParam('login.lastLogin');
The process of wrapping original request as TJsonRequest is implemented in TJsonContentTypeMiddleware middleware (View TJsonContentTypeMiddleware source).
. When you attach this middleware to a route, everytime application receive method POST, PUT, PATCH or DELETE with Content-Type header set to application/json, original request will be wrapped inside TJsonRequest (View TJsonRequest source).
To register this middleware, use TJsonContentTypeMiddlewareFactory class.
container.add(
'jsonReq',
TJsonContentTypeMiddlewareFactory.create()
);
In route registration, attach middleware to route, as shown in following code.
router.post(
'/submit',
container['submit.controller'] as IRequestHandler
).add(container['jsonReq'] as IMiddleware);
Please read middleware documentation for information how to work with middleware.
See Fano Json Request for example how to use TJsonContentTypeMiddleware middleware to handle request with JSON body.