docs.sheetjs.com/docz/static/maple/sheetjs-maple.c

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2023-10-03 22:58:43 +00:00
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "maplec.h"
#include "duktape.h"
/* --- EXPORT_DECL macro from official example --- */
#if !defined(EXPORT_DECL)
#ifdef _MSC_VER
#define EXPORT_DECL __declspec(dllexport)
#else
#define EXPORT_DECL
#endif
#endif
/* --- the SheetJS + Duktape demo cover these machinations --- */
#define FAIL_LOAD { \
duk_push_undefined(ctx); \
perror("Error in load_file"); \
return 1; \
}
static char *read_file(const char *filename, size_t *sz) {
FILE *f = fopen(filename, "rb");
if(!f) return NULL;
long fsize; { fseek(f, 0, SEEK_END); fsize = ftell(f); fseek(f, 0, SEEK_SET); }
char *buf = (char *)malloc(fsize * sizeof(char));
*sz = fread((void *) buf, 1, fsize, f);
fclose(f);
return buf;
}
static duk_int_t eval_file(duk_context *ctx, const char *filename) {
size_t len; char *buf = read_file(filename, &len);
if(!buf) FAIL_LOAD
duk_push_lstring(ctx, (const char *)buf, (duk_size_t)len);
duk_int_t retval = duk_peval(ctx);
duk_pop(ctx);
return retval;
}
static duk_int_t load_file(duk_context *ctx, const char *filename, const char *var) {
size_t len; char *buf = read_file(filename, &len);
if(!buf) FAIL_LOAD
duk_push_external_buffer(ctx);
duk_config_buffer(ctx, -1, buf, len);
duk_put_global_string(ctx, var);
return 0;
}
static duk_int_t save_file(duk_context *ctx, const char *filename, const char *var) {
duk_get_global_string(ctx, var);
duk_size_t sz;
char *buf = (char *)duk_get_buffer_data(ctx, -1, &sz);
if(!buf) return 1;
FILE *f = fopen(filename, "wb"); fwrite(buf, 1, sz, f); fclose(f);
return 0;
}
#define FAIL_DUK(cmd) { \
const char *errmsg = duk_safe_to_string(ctx, -1); \
duk_destroy_heap(ctx); \
MapleRaiseError2(kv, "error in %1 : %2", ToMapleString(kv, cmd), ToMapleString(kv, errmsg)); \
return NULL; \
}
#define DOIT(cmd) duk_eval_string_noresult(ctx, cmd);
/* SheetToXLSX function */
EXPORT_DECL ALGEB M_DECL SheetToXLSX( MKernelVector kv, ALGEB *args ) {
duk_int_t res = 0;
/* get filename */
if(MapleNumArgs(kv, (ALGEB)args) != 1) {
MapleRaiseError(kv, "must specify a filename");
return NULL;
}
if(!IsMapleString(kv, args[1])) {
MapleRaiseError(kv, "filename must be a string");
return NULL;
}
const char *filename = MapleToString(kv, args[1]);
/* initialize duktape */
duk_context *ctx = duk_create_heap_default();
/* duktape does not expose a standard "global" by default */
DOIT("var global = (function(){ return this; }).call(null);");
/* load SheetJS library */
res = eval_file(ctx, "shim.min.js");
if(res != 0) FAIL_DUK("shim load")
res = eval_file(ctx, "xlsx.full.min.js");
if(res != 0) FAIL_DUK("library load")
/* read file */
res = load_file(ctx, filename, "buf");
if(res != 0) FAIL_DUK("file load")
printf("Loaded file %s\n", filename);
/* parse workbook and write to XLSX */
DOIT("wb = XLSX.read(buf.slice(0, buf.length), {type:'buffer'});");
DOIT("newbuf = (XLSX.write(wb, {type:'array', bookType:'xlsx'}));");\
/* write file */
res = save_file(ctx, "sheetjsw.xlsx", "newbuf");\
if(res != 0) FAIL_DUK("save sheetjsw.xlsx")
/* return filename */
return ToMapleString(kv, "sheetjsw.xlsx");
}