I am trying to implement datatables server-side-processing in golang with gin framework. I have my resource in php. I want to convert it into golang gin. Need a little help.
// php codes
$params = $_REQUEST;
$draw = $params["draw"];
$orderColumn = $params['order'][0]['column'];
$sortColumnDir = $params['order'][0]['dir'];
// golang gin codes
// no idea what to do to get $_REQUEST as in php
// $params = $_REQUEST; // here what will be go code in gin ?
// I have tried following, but not sure
draw := c.Request.Form.Get("draw")
orderColumn := c.Request.Form.Get("order[0][column]")
sortColumnDir := c.Request.Form.Get("order[0][dir]")
Stop thinking about $_REQUEST. Simply forget it exists. There is luckily no such thing in Go (for various reasons), and will never be.
Read the docs; figure out that c.Request is actually a
http.Request.
Read its docs,
figure out its Form field is an url.Values.
Read its docs, figure out it's a map of keys which are names of query parameters to slices of the arguments of these parameters.
Armed with that knowledge, in your request processing code, dump the whole contents of the c.Request.Form somewhere (that depends on how you run your server — if you fire it off right in a terminal for testing, then a simple log.Print(c.Request.Form) will suffice).
Study what's there.
Work from there.
Related
I'm implementing server using GIN Framework.
The Gin framework has a handler for each route.
Each function handler has it's own controller that returns some result (basically error)
package controller
var (
ErrTooManyAttempts = errors.New("too many attempts")
ErrNoPermission = errors.New("no permission")
ErrNotAvailable = errors.New("not available")
)
This errors are created for developers and logging, so we need to beautify and translate these before sending them to the client.
To be able to get translation we should know the key of the message.
But the problem is I need to bind these errors in some map[error]string (key) to get translation key by error.
It's quite complex because I have to bind all the errors with the corresponding keys.
To improve it, I'd like to use reflection:
Get all variables in the package
Walk through and find Err prefix
Generate translation key based on package name and error name, ex: controller-ErrTooManyAttempts
Merge translation file, so it should look like this:
`
{
"controller-ErrTooManyAttempts": "Too many attempts. Please try again later",
"controller-ErrNoPermission": "Permission to perform this action is denied",
"controller-ErrNotAvailable": "Service not available. Please try again later"
}
`
What is the correct way to translate errors from the package? Is it possible to provide me with some example?
I'm building a NativeScript plugin for iOS to integrate a card payment terminal as an external accessory. It is almost done, and working, but I have problem with passing one argument called "optionals". This is the whole code I'm trying to implement. It's the payworks framework for a Miura terminal. http://www.payworks.mpymnt.com/node/143
MPTransactionParameters *tp = [MPTransactionParameters chargeWithAmount:[NSDecimalNumber decimalNumberWithString:#"5.00"]
currency:MPCurrencyEUR
optionals:^(id<MPTransactionParametersOptionals> _Nonnull optionals) {
optionals.subject = #"Bouquet of Flowers";
optionals.customIdentifier = #"yourReferenceForTheTransaction";
}];
I cannot find a way of sending this "optionals" function.
In the generate typing metadata I see the MPTransactionParametersOptionals is a #protocol, but still don't know how to use it here as a parameter.
This is my current javascript code for the block
const tp = MPTransactionParameters.chargeWithAmountCurrencyOptionals(
amount,
MPCurrencyEUR,
function (optionals) {
console.log(optionals); //logs the newly created MPTransactionParameters instance, with set amount and currency properties, but cannot touch or set the optional properties.
}
);
The 3rd parameter of chargeWithAmountCurrencyOptionals() should be a function, but I'm doing it wrong, and searched everywhere in google how to do it but no success. I'm already trying for 2 days.
It is working, when the 3rd parameter is null, but I need the set the optional properties.
EDIT: adding the metadata. There are a lot of typings for MPtransactionParameters, so I decided to give you the whole file so you can search.
https://drive.google.com/open?id=1kvDoXtGbCoeCT20b9_t2stc2Qts3VyQx
EDIT2: Adding the typings:
https://drive.google.com/open?id=1lZ3ULYHbX7DXdUQMPoZeSfyEZrjItSOS
I am doing some web develoment using the go programming language using the package html/template. At some point of the code, I need to call the function template.ParseFiles(...) so I can create a template from those files ad then execute it using temp.Execute(w,data). I would like to know if it is better to create the template on each request or to do it once in the main and declare a global variable.
Right now I do it on each request on my handle functions, like most tutorials do. However, I don't know If I'm wasting resources by doing it on each request instead of having them as global variables.
This is how it looks on each request
func ViewStats(w http.ResponseWriter, r *http.Request) {
//Get stuff from db and put them in data
//...
//return data to user
tmp, err := template.ParseFiles("views/guest-layout.html",
"views/stats.html")
if err != nil {
fmt.Println(err)
} else {
tmp.Execute(w,data)
}
}
I would like to know if this is better:
var temp1 template.Template
func main() {
temp1, err = template.ParseFiles("file1","file2")
//...
}
As usual: It depends.
But first some nuance:
You should never do template parsing (or anything else interesting) in your main() function. Instead, your main() function should call methods (or a single method) that kicks off the chain of interesting things in your program.
Go doesn't have globals, so it's not actually an option to store your parsed templates in a global variable in the first place. The closest Go has to global variables is package variables. You could store your parsed templates in a package variable in the main package, but this is also bad form, as your main package (except for tiny, trivial programs), should just be an entry point, and otherwise nearly empty.
But now, on to the core of your question:
Should you parse templates per request, or per run?
And here it depends.
If you have templates that change frequently (i.e. during development, when you're constantly editing your HTML files), once per request can be best.
But this is far less efficient than just parsing once, so in production, you may wish to parse the templates once on startup only. Then you can store the templates in a package variable, or better, in a struct that is initialized at runtime. But I leave that to you.
But what may be best is actually a bit of a compromise between the two approaches. It may be best to load your templates at start-up, and re-load them occasionally, either automatically (say, every 5 minutes), or watch your filesystem, and reload them whenever the on-disk representation of the templates changes.
How to do this is left as an exercise for the reader.
I'm trying to do something that seems like it should be trivial until I read up and now it seems like it should be really complex. ;-)
I've knocked up a test pattern to illustrate:
http://play.golang.org/p/Re88vJZvPT
At the most basic I'm trying to have a function that can read data from a channel and spit it out on another one. Easy. The test does this as long as you use the pusher function shown.
However the problem with this is that doing it this way I would need a different pusher function for each type of data I want to push through it.
Now I've done similar things in the past with an empty interface as nothing in the pusher code cares about what's in the data structure. What I can't figure out is when I'm dealing with channels of an un-cared-about data structure.
To illustrate the concept of what I'm trying to achieve please see the function pusher_naive_generic.
However that doesn't work either so more reading up implied the way to do it was making use of reflection and finally you see my pusher_reflect_generic function(obviously this won't achieve the same intended function as the others it's showing where I got to before getting stuck).
Which still fails because I can't get from an interface that contains a chan to the structure read from that chan.
Hopefully the code makes more sense of what I'm trying to achieve than my words actually do. I can make all of this work by explicitly coding for every type, but what I can't figure out how to do is code it for any future type.
If I have understood your question correctly, then this might be the solution:
http://play.golang.org/p/xiDO7xkoW4
func forwardChannel(i interface{}, o interface{}) {
it, ot := reflect.TypeOf(i), reflect.TypeOf(o)
if it != ot {
panic("forwardChannel: both arguments must be of the same type")
}
iv, ov := reflect.ValueOf(i), reflect.ValueOf(o)
for {
v, k := iv.Recv()
if !k {
break
}
ov.Send(v)
}
ov.Close()
}
Note that Recv, Send and Close panic if i and o are not channels.
I am trying to write an online message board in Haxe (OpenFL). There are lots of server/client examples online. But I am new to this area and I do not understand any of them. What is the easiest way to send a list of objects between server and client? Could you guys give an example?
You could use JSON
You can put this in your openFL project (client):
var myData = [1,2,3,4,5];
var http = new haxe.Http("server.php");
http.addParameter("myData", haxe.Json.stringify(myData));
http.onData = function(resultData) {
trace('the data is send to server, this is the response:' + resultData);
}
http.request(true);
If you have a server.php file, you can access the data like this:
$myData = json_decode($_POST["myData"]);
If the server returns Json data which needs to be read in the client, then in Haxe you need to do haxe.Json.parse(resultData);
EDIT: I'm not still sure if the user's problem is really about sending "a list of objects"; see comment to the question...
The easiest way is to use Haxe Serialization, either with Haxe Remoting or with your own protocol on top of TCP/UDP. The choice of protocol depends whether you already have something built and whether you will be calling functions or simply getting/posting data.
In either case, haxe.Serializer/Unserializer will give you a format to transmit most (if not all) Haxe objects from client to server with minimal code.
See the following minimal example (from the manual) on how to use the serialization APIs. The format is string based and specified.
import haxe.Serializer;
import haxe.Unserializer;
class Main {
static function main() {
var serializer = new Serializer();
serializer.serialize("foo");
serializer.serialize(12);
var s = serializer.toString();
trace(s); // y3:fooi12
var unserializer = new Unserializer(s);
trace(unserializer.unserialize()); // foo
trace(unserializer.unserialize()); // 12
}
}
Finally, you could also use other serialization formats like JSON (with haxe.Json.stringify/parse) or XML, but they wouldn't be so convenient if you're dealing with enums, class instances or other data not fully supported by these formats.