jsonrpc: github.com/ybbus/jsonrpc Index | Files

package jsonrpc

import "github.com/ybbus/jsonrpc"

Package jsonrpc provides a JSON-RPC 2.0 client that sends JSON-RPC requests and receives JSON-RPC responses using HTTP.

Index

Package Files

jsonrpc.go

func Params Uses

func Params(params ...interface{}) interface{}

Params is a helper function that uses the same parameter syntax as Call(). But you should consider to always use NewRequest() instead.

e.g. to manually create an RPCRequest object: request := &RPCRequest{

Method: "myMethod",
Params: Params("Alex", 35, true),

}

same with new request: request := NewRequest("myMethod", "Alex", 35, true)

If you know what you are doing you can omit the Params() call but potentially create incorrect rpc requests: request := &RPCRequest{

Method: "myMethod",
Params: 2, <-- invalid since a single primitive value must be wrapped in an array --> no magic without Params()

}

correct: request := &RPCRequest{

Method: "myMethod",
Params: []int{2}, <-- invalid since a single primitive value must be wrapped in an array

}

type HTTPError Uses

type HTTPError struct {
    Code int
    // contains filtered or unexported fields
}

HTTPError represents a error that occurred on HTTP level.

An error of type HTTPError is returned when a HTTP error occurred (status code) and the body could not be parsed to a valid RPCResponse object that holds a RPCError.

Otherwise a RPCResponse object is returned with a RPCError field that is not nil.

func (*HTTPError) Error Uses

func (e *HTTPError) Error() string

Error function is provided to be used as error object.

type RPCClient Uses

type RPCClient interface {
    // Call is used to send a JSON-RPC request to the server endpoint.
    //
    // The spec states, that params can only be an array or an object, no primitive values.
    // So there are a few simple rules to notice:
    //
    // 1. no params: params field is omitted. e.g. Call("getinfo")
    //
    // 2. single params primitive value: value is wrapped in array. e.g. Call("getByID", 1423)
    //
    // 3. single params value array or object: value is unchanged. e.g. Call("storePerson", &Person{Name: "Alex"})
    //
    // 4. multiple params values: always wrapped in array. e.g. Call("setDetails", "Alex, 35, "Germany", true)
    //
    // Examples:
    //   Call("getinfo") -> {"method": "getinfo"}
    //   Call("getPersonId", 123) -> {"method": "getPersonId", "params": [123]}
    //   Call("setName", "Alex") -> {"method": "setName", "params": ["Alex"]}
    //   Call("setMale", true) -> {"method": "setMale", "params": [true]}
    //   Call("setNumbers", []int{1, 2, 3}) -> {"method": "setNumbers", "params": [1, 2, 3]}
    //   Call("setNumbers", 1, 2, 3) -> {"method": "setNumbers", "params": [1, 2, 3]}
    //   Call("savePerson", &Person{Name: "Alex", Age: 35}) -> {"method": "savePerson", "params": {"name": "Alex", "age": 35}}
    //   Call("setPersonDetails", "Alex", 35, "Germany") -> {"method": "setPersonDetails", "params": ["Alex", 35, "Germany"}}
    //
    // for more information, see the examples or the unit tests
    Call(method string, params ...interface{}) (*RPCResponse, error)

    // CallRaw is like Call() but without magic in the requests.Params field.
    // The RPCRequest object is sent exactly as you provide it.
    // See docs: NewRequest, RPCRequest, Params()
    //
    // It is recommended to first consider Call() and CallFor()
    CallRaw(request *RPCRequest) (*RPCResponse, error)

    // CallFor is a very handy function to send a JSON-RPC request to the server endpoint
    // and directly specify an object to store the response.
    //
    // out: will store the unmarshaled object, if request was successful.
    // should always be provided by references. can be nil even on success.
    // the behaviour is the same as expected from json.Unmarshal()
    //
    // method and params: see Call() function
    //
    // if the request was not successful (network, http error) or the rpc response returns an error,
    // an error is returned. if it was an JSON-RPC error it can be casted
    // to *RPCError.
    //
    CallFor(out interface{}, method string, params ...interface{}) error

    // CallBatch invokes a list of RPCRequests in a single batch request.
    //
    // Most convenient is to use the following form:
    // CallBatch(RPCRequests{
    //   NewRequest("myMethod1", 1, 2, 3),
    //   NewRequest("myMethod2", "Test"),
    // })
    //
    // You can create the []*RPCRequest array yourself, but it is not recommended and you should notice the following:
    // - field Params is sent as provided, so Params: 2 forms an invalid json (correct would be Params: []int{2})
    // - you can use the helper function Params(1, 2, 3) to use the same format as in Call()
    // - field JSONRPC is overwritten and set to value: "2.0"
    // - field ID is overwritten and set incrementally and maps to the array position (e.g. requests[5].ID == 5)
    //
    //
    // Returns RPCResponses that is of type []*RPCResponse
    // - note that a list of RPCResponses can be received unordered so it can happen that: responses[i] != responses[i].ID
    // - RPCPersponses is enriched with helper functions e.g.: responses.HasError() returns  true if one of the responses holds an RPCError
    CallBatch(requests RPCRequests) (RPCResponses, error)

    // CallBatchRaw invokes a list of RPCRequests in a single batch request.
    // It sends the RPCRequests parameter is it passed (no magic, no id autoincrement).
    //
    // Consider to use CallBatch() instead except you have some good reason not to.
    //
    // CallBatchRaw(RPCRequests{
    //   &RPCRequest{
    //     ID: 123,            // this won't be replaced in CallBatchRaw
    //     JSONRPC: "wrong",   // this won't be replaced in CallBatchRaw
    //     Method: "myMethod1",
    //     Params: []int{1},   // there is no magic, be sure to only use array or object
    //   },
    //   &RPCRequest{
    //     ID: 612,
    //     JSONRPC: "2.0",
    //     Method: "myMethod2",
    //     Params: Params("Alex", 35, true), // you can use helper function Params() (see doc)
    //   },
    // })
    //
    // Returns RPCResponses that is of type []*RPCResponse
    // - note that a list of RPCResponses can be received unordered
    // - the id's must be mapped against the id's you provided
    // - RPCPersponses is enriched with helper functions e.g.: responses.HasError() returns  true if one of the responses holds an RPCError
    CallBatchRaw(requests RPCRequests) (RPCResponses, error)
}

RPCClient sends JSON-RPC requests over HTTP to the provided JSON-RPC backend.

RPCClient is created using the factory function NewClient().

func NewClient Uses

func NewClient(endpoint string) RPCClient

NewClient returns a new RPCClient instance with default configuration.

endpoint: JSON-RPC service URL to which JSON-RPC requests are sent.

func NewClientWithOpts Uses

func NewClientWithOpts(endpoint string, opts *RPCClientOpts) RPCClient

NewClientWithOpts returns a new RPCClient instance with custom configuration.

endpoint: JSON-RPC service URL to which JSON-RPC requests are sent.

opts: RPCClientOpts provide custom configuration

type RPCClientOpts Uses

type RPCClientOpts struct {
    HTTPClient    *http.Client
    CustomHeaders map[string]string
}

RPCClientOpts can be provided to NewClientWithOpts() to change configuration of RPCClient.

HTTPClient: provide a custom http.Client (e.g. to set a proxy, or tls options)

CustomHeaders: provide custom headers, e.g. to set BasicAuth

type RPCError Uses

type RPCError struct {
    Code    int         `json:"code"`
    Message string      `json:"message"`
    Data    interface{} `json:"data,omitempty"`
}

RPCError represents a JSON-RPC error object if an RPC error occurred.

Code: holds the error code

Message: holds a short error message

Data: holds additional error data, may be nil

See: http://www.jsonrpc.org/specification#error_object

func (*RPCError) Error Uses

func (e *RPCError) Error() string

Error function is provided to be used as error object.

type RPCRequest Uses

type RPCRequest struct {
    Method  string      `json:"method"`
    Params  interface{} `json:"params,omitempty"`
    ID      int         `json:"id"`
    JSONRPC string      `json:"jsonrpc"`
}

RPCRequest represents a JSON-RPC request object.

Method: string containing the method to be invoked

Params: can be nil. if not must be an json array or object

ID: may always set to 1 for single requests. Should be unique for every request in one batch request.

JSONRPC: must always be set to "2.0" for JSON-RPC version 2.0

See: http://www.jsonrpc.org/specification#request_object

Most of the time you shouldn't create the RPCRequest object yourself. The following functions do that for you: Call(), CallFor(), NewRequest()

If you want to create it yourself (e.g. in batch or CallRaw()), consider using Params(). Params() is a helper function that uses the same parameter syntax as Call().

e.g. to manually create an RPCRequest object: request := &RPCRequest{

Method: "myMethod",
Params: Params("Alex", 35, true),

}

If you know what you are doing you can omit the Params() call to avoid some reflection but potentially create incorrect rpc requests: request := &RPCRequest{

Method: "myMethod",
Params: 2, <-- invalid since a single primitive value must be wrapped in an array --> no magic without Params()

}

correct: request := &RPCRequest{

Method: "myMethod",
Params: []int{2}, <-- invalid since a single primitive value must be wrapped in an array

}

func NewRequest Uses

func NewRequest(method string, params ...interface{}) *RPCRequest

NewRequest returns a new RPCRequest that can be created using the same convenient parameter syntax as Call()

e.g. NewRequest("myMethod", "Alex", 35, true)

type RPCRequests Uses

type RPCRequests []*RPCRequest

RPCRequests is of type []*RPCRequest. This type is used to provide helper functions on the request list

type RPCResponse Uses

type RPCResponse struct {
    JSONRPC string      `json:"jsonrpc"`
    Result  interface{} `json:"result,omitempty"`
    Error   *RPCError   `json:"error,omitempty"`
    ID      int         `json:"id"`
}

RPCResponse represents a JSON-RPC response object.

Result: holds the result of the rpc call if no error occurred, nil otherwise. can be nil even on success.

Error: holds an RPCError object if an error occurred. must be nil on success.

ID: may always be 0 for single requests. is unique for each request in a batch call (see CallBatch())

JSONRPC: must always be set to "2.0" for JSON-RPC version 2.0

See: http://www.jsonrpc.org/specification#response_object

func (*RPCResponse) GetBool Uses

func (RPCResponse *RPCResponse) GetBool() (bool, error)

GetBool converts the rpc response to a bool and returns it.

If result was not a bool an error is returned.

func (*RPCResponse) GetFloat Uses

func (RPCResponse *RPCResponse) GetFloat() (float64, error)

GetFloat converts the rpc response to float64 and returns it.

If result was not an float64 an error is returned.

func (*RPCResponse) GetInt Uses

func (RPCResponse *RPCResponse) GetInt() (int64, error)

GetInt converts the rpc response to an int64 and returns it.

If result was not an integer an error is returned.

func (*RPCResponse) GetObject Uses

func (RPCResponse *RPCResponse) GetObject(toType interface{}) error

GetObject converts the rpc response to an arbitrary type.

The function works as you would expect it from json.Unmarshal()

func (*RPCResponse) GetString Uses

func (RPCResponse *RPCResponse) GetString() (string, error)

GetString converts the rpc response to a string and returns it.

If result was not a string an error is returned.

type RPCResponses Uses

type RPCResponses []*RPCResponse

RPCResponses is of type []*RPCResponse. This type is used to provide helper functions on the result list

func (RPCResponses) AsMap Uses

func (res RPCResponses) AsMap() map[int]*RPCResponse

AsMap returns the responses as map with response id as key.

func (RPCResponses) GetByID Uses

func (res RPCResponses) GetByID(id int) *RPCResponse

GetByID returns the response object of the given id, nil if it does not exist.

func (RPCResponses) HasError Uses

func (res RPCResponses) HasError() bool

HasError returns true if one of the response objects has Error field != nil

Package jsonrpc imports 7 packages (graph) and is imported by 12 packages. Updated 2019-03-19. Refresh now. Tools for package owners.