jquery.jsonrpc.js

/*
 * jQuery JSON-RPC Plugin
 *
 * @version: 1.1(2016-03-23)
 * @author hagino3000 <http://twitter.com/hagino3000> (Takashi Nishibayashi)
 * @author alanjds <http://twitter.com/alanjds> (Alan Justino da Silva)
 *
 * A JSON-RPC 2.0 implementation for jQuery.
 * JSON-RPC is a stateless, light-weight remote procedure call (RPC) protocol.
 * Read more in the <http://www.jsonrpc.org/specification>
 */
(function($) {
    var rpcId = 1;
    var emptyFn = function(){};

    function makePostPayload(rpcParam) {
        return {
            jsonrpc: '2.0',
            method: rpcParam.method || '',
            params: rpcParam.params || {},
            id: rpcId++
        };
    }

    function makePostBody(rpcParam) {
        var payload = $.isArray(rpcParam) ? rpcParam.map(makePostPayload) : makePostPayload(rpcParam);
        return JSON.stringify(payload);
    }

    function sortBatchResults(results) {
        return results.sort(rpcIdComparator);
    }

    function rpcIdComparator(a, b) {
        return a.id < b.id ? -1 : 1;
    }

    function jsonrpc(rpcParam, ajaxOpts) {
        var deferred = new $.Deferred();

        ajaxOpts = ajaxOpts || {};
        var successCallback = ajaxOpts.success || emptyFn;
        var errorCallback = ajaxOpts.error || emptyFn;
        delete ajaxOpts.success;
        delete ajaxOpts.error;

        var isBatch = $.isArray(rpcParam);
        var ajaxParams = $.extend({
            url: (isBatch ? rpcParam[0].url : rpcParam.url) || $.jsonrpc.defaultUrl,
            contentType: 'application/json',
            dataType: 'text',
            dataFilter: function(data, type) {
                try {
                    return JSON.parse(data);
                } catch (e) {
                    result = {
                        status: null,
                        code: -32603,
                        message: "Internal error",
                        data: null
                    };
                    errorCallback(result);
                    deferred.reject(result);
                }
            },
            type: 'POST',
            processData: false,
            data: makePostBody(rpcParam),
            success: function(resp) {
                if (isBatch) {
                    var orderedResults = sortBatchResults(resp);
                    successCallback(orderedResults);
                    deferred.resolve(orderedResults);
                    return;
                } else {
                    if (resp.hasOwnProperty('error')) {
                        // HTTP Response 20x but error
                        errorCallback(resp.error);
                        deferred.reject(resp.error);
                        return;
                    }
                    if (resp.hasOwnProperty('result')) {
                        successCallback(resp.result);
                        deferred.resolve(resp.result);
                        return;
                    }
                }
                throw 'Invalid response returned';
            },
            error: function(xhr, status, error) {
                var result = null;
                if (error === 'timeout') {
                    result = {
                        status: status,
                        code: -32000,
                        message: "Request Timeout",
                        data: null
                    };
                } else {
                    try {
                        var res = JSON.parse(xhr.responseText);
                        result = res.error;
                    } catch (e) {
                        result = {
                            status: status,
                            code: -32603,
                            message: error,
                            data: xhr.responseText
                        };
                    }
                }
                errorCallback(result);
                deferred.reject(result);
            }
        }, ajaxOpts);

        $.ajax(ajaxParams);

        return deferred.promise();
    }

    $.extend({
        jsonrpc: jsonrpc
    });
    $.jsonrpc.defaultUrl = '/jsonrpc';

})(jQuery);