2.1.21.11 okutil_http_get

Description

get a string from a web service

Syntax

int okutil_http_get( LPCSTR lpcszURL, string * pstrResult, int nConnectTimeout = 0, int nResponseTimeout = 0 )

Parameters

lpcszURL

[input] the web service URL

pstrResult

[output] result from the call

nConnectTimeout

[input] optional, in seconds

nResponseTimeout

[input] optional, in seconds

Return

0 if succcess, otherwise an negative error code

Examples

EX1

void test_rest_service()
{
    string result;
    int err = okutil_http_get("http://services.groupkt.com/state/get/IND/UP", &result);
    if( err )
        printf("Error %d\n", err);
    else //no err
    {
        printf("%s\n", result);
        Tree tr;
        JSON.FromString(tr, result);
        out_tree(tr);
    }
}

EX2

//assume default new project with active book
void so2()
{
    string url = "http://api.openweathermap.org/pollution/v1/so2/0.0,10.0/2016Z.json?appid=f80146dfac8f9ecbc2bbcc1cf97465cb";
    string strJS;
    int err = okutil_http_get(url, &strJS);
    if( err != 0 )
        return;
    Tree tr;
    JSON.FromString(tr, strJS);
    Worksheet wks = Project.ActiveLayer();
    Column col1 = wks.Columns(0);
    Column col2 = wks.Columns(1);
    vectorbase &v1 = col1.GetDataObject();
    vectorbase &v2 = col2.GetDataObject();
    JSON.TreeToVector(tr.data, v1, "pressure");
    JSON.TreeToVector(tr.data, v2, "value");
}

EX3

#include <ocu.h> //for ocu_url_encode
void yy()
{
    string url ="https://query.yahooapis.com/v1/public/yql?q=";
    string strSearch = "select item.condition from weather.forecast where woeid = 2487889";
    ocu_url_encode(&strSearch);
    url += strSearch;
    url += "&format=json&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys";
    string strJS;
    int err = okutil_http_get(url, &strJS);
    if( err != 0 )
        return;
    Tree tr;
    JSON.FromString(tr, strJS);
    out_tree(tr);
}

Remark

See Also

JSON::FromString

JSON::TreeToVector

okutil_http_range_request

Header to Included

origin.h

Reference