Mirrors/libwebsockets
1
0
Fork 0
mirror of https://github.com/warmcat/libwebsockets.git synced 2025-03-16 00:00:07 +01:00
Code Issues Releases Wiki Activity
libwebsockets/minimal-examples-lowlevel/api-tests/api-test-lhp/main.c

320 lines
8.1 KiB
C
Raw Normal View History

lhp: Lightweight HTML Parser Introduce a very lightweight html5 + css2.1+ stateful stream parser, along the same lines as the lws json and cbor ones. This is interesting primarily because of just how low-resource it is for modest css + html, it uses an lwsac to hold the entirity of the css in memory at once but the html is parsed in chunks without any need to keep previous chunks around (chunks may be as small as 1 byte). A user callback receives element entry and exit callbacks with payload and all attributes parsed out, CSS related to the active element stack is parsed to provide a list of active css attributes, which takes heap for the duration of the parsing. In effect this provides rich information about the html and css state to the callback, which has the job of producing the layout in a user-defined way. As such, there is no DOM in memory at one time, there is only a stack of active elements like <html><body><div>xxx with their associated attributes (like class). So as it is, it does not support DOM modification such as JS changing elements after parsing, although elements with interesting IDs could be kept around by the callback. There is a corresponding tiny and relatively flat heap usage regardless of html size. Default CSS is specified as recommended in the CSS 2.1 standard. Inline <style></style> elements are supported, but not pre-html5 style= in element attributes, since these are incompatible with strict CSP. What the attributes should mean on your system, eg, font-size, font-family etc is left for the user callback to decide, along with how to lay out the items using the CSS attributes, and render them. Fixed point 32.32 constants are used (fraction expressed at parts in 100M) instead of floating point. If you have presentation needs, even on a constrained display on a constrained microcontroller, this makes it feasible to use standardized markup and styling instead of roll your own.
2021-12-19 19:10:20 +00:00
/*
* lws-api-test-lhp
*
* Written in 2010-2022 by Andy Green <andy@warmcat.com>
*
* This file is made available under the Creative Commons CC0 1.0
* Universal Public Domain Dedication.
*
* sanity tests for lhp
*/
#include <libwebsockets.h>
#include <stdio.h>
static const char * const cb_reasons[] = {
"LHPCB_CONSTRUCTED",
"LHPCB_DESTRUCTED",
"LHPCB_COMPLETE",
"LHPCB_FAILED",
"LHPCB_ELEMENT_START", /* reported at end of <> */
"LHPCB_ELEMENT_END",
"LHPCB_CONTENT",
"LHPCB_COMMENT",
};
static const char * const html_tests[] = {
/* test 1 */
"hello",
/* test 2 */
"<!doctype html>",
/* test 3 */
"<!DOCTYPE html PUBLIC \"-//W3C//DTD HTML 4.0//EN\">",
/* test 4 */
"<!doctype html><html><head></head><body>hello</body></html>",
/* test 5 */
"<!doctype html>\n"
"<html>\n"
"<head>\n"
"<title>An HTML standard template</title>\n"
"<meta charset=\"utf-8\" />\n"
"</head>\n"
"<body>\n"
"<h1>heading</h1>\n"
"<b>bold</b>, normal<br>\n"
"</body>\n"
"</html>\n",
"<>",
"<thing></thing>",
"<thing a></thing>",
"<thing a b=c></thing>",
"<thing a b='d'></thing>",
"<thing a b=\"e\"></thing>",
"<thing ></thing>",
"<thing a ></thing>",
"<thing a b=c ></thing>",
"<thing a b='d' ></thing>",
"<thing a b=\"e\" ></thing>",
"<br/>",
"<br />",
"<br something/>",
"<br something />",
"<!--comment-->",
"<!doctype html>\n"
"<html>\n"
"<head>\n"
"<title>Test html</title>\n"
"<meta charset=\"utf-8\" />\n"
"</head>\n"
"<style>"
"h1 { font-size: 32px },"
"b { font-weight: bold }"
"</style>"
"<body>\n"
"<h1>libwebsockets.org</h1>\n"
"A bunch of normal text, long enough that it is going to want to wrap<br>"
"<b>bold</b>, normal<br>\n"
"<img src=\"something.png\">"
"</body>\n"
"</html>\n",
"&#x20ac;&#x1f44d;",
"<html><head><title>the title</title></head><body><style>"
"<!-- css comment-->"
"/* another css comment */"
"body { font-size: 16px; font-family: default }"
"div { font-size: 16px; display: inline-block }"
"h1 { font-size: 32px; font-family: \"term\" }"
"b { font-weight: bold; color: #f00 }"
".wordy { position: absolute; width: 280px; left: 10px; right: 10px; font-size: 16px; color: #7a7b7c }"
".cat { display: list-item; }"
"</style>"
"<h1>Heading</h1>\n"
"<div class=\"wordy cat\">"
"A bunch of normal <b> and bold</b>text in a div"
"</div>"
"hello</body></html>"
};
static unsigned int m, step;
static int
dump_atr(lws_dll2_t *d, void *user)
{
lhp_atr_t *atr = lws_container_of(d, lhp_atr_t, list);
const char *p = (const char *)&atr[1];
printf("{ \"%.*s\", \"%.*s\" }, ",
(int)atr->name_len, p, (int)atr->value_len, p + atr->name_len + 1);
return 0;
}
#if 0
static int
dump_css_atr(lws_dll2_t *d, void *user)
{
lcsp_atr_ptr_t *pa = lws_container_of(d, lcsp_atr_ptr_t, list);
lcsp_atr_t *a = pa->atr;
if (a->unit == LCSP_UNIT_RGBA)
lwsl_notice("css attr: color 0x%08x\n", a->u.rgba);
else
lwsl_notice("css attr: %d %u.%u %u\n", a->propval, a->u.i.whole, a->u.i.frac, a->unit);
return 0;
}
#endif
static lws_stateful_ret_t
test_cb(lhp_ctx_t *ctx, char reason)
{
lhp_pstack_t *ps = lws_container_of(ctx->stack.tail, lhp_pstack_t, list);
const lcsp_atr_t *a;
printf("{ %s, %u, \"%.*s\", %u, { ", cb_reasons[(unsigned int)reason], ctx->npos, ctx->npos, ctx->buf, ps->atr.count);
if (reason == LHPCB_ELEMENT_START || reason == LHPCB_ELEMENT_END) {
lws_dll2_foreach_safe(&ps->atr, NULL, dump_atr);
a = lws_css_cascade_get_prop_atr(ctx, LCSP_PROP_DISPLAY);
if (a)
lwsl_notice("display: %d\n", a->propval);
a = lws_css_cascade_get_prop_atr(ctx, LCSP_PROP_COLOR);
if (a)
lwsl_notice("color: %d 0x%08X\n", a->propval, a->u.rgba);
//lwsl_notice("color: active_stz %d, atr %d\n", ctx->active_stanzas.count, ctx->active_atr.count);
//lws_dll2_foreach_safe(&ctx->active_atr, NULL, dump_css_atr);
a = ps->css_position;
if (a)
lwsl_notice("position: %d\n", a->propval);
a = ps->css_width;
if (a)
lwsl_notice("width: %d.%u\n", a->u.i.whole, a->u.i.frac);
a = ps->css_height;
if (a)
lwsl_notice("height: %d.%u\n", a->u.i.whole, a->u.i.frac);
a = ps->css_pos[CCPAS_TOP];
if (a)
lwsl_notice("top: %d.%u\n", a->u.i.whole, a->u.i.frac);
a = ps->css_pos[CCPAS_RIGHT];
if (a)
lwsl_notice("right: %d.%u\n", a->u.i.whole, a->u.i.frac);
a = ps->css_pos[CCPAS_BOTTOM];
if (a)
lwsl_notice("bottom: %d.%u\n", a->u.i.whole, a->u.i.frac);
a = ps->css_pos[CCPAS_LEFT];
if (a)
lwsl_notice("left: %d.%u\n", a->u.i.whole, a->u.i.frac);
a = ps->css_margin[CCPAS_TOP];
if (a)
lwsl_notice("margin top: %d.%u\n", a->u.i.whole, a->u.i.frac);
a = ps->css_margin[CCPAS_RIGHT];
if (a)
lwsl_notice("margin right: %d.%u\n", a->u.i.whole, a->u.i.frac);
a = ps->css_margin[CCPAS_BOTTOM];
if (a)
lwsl_notice("margin bottom: %d.%u\n", a->u.i.whole, a->u.i.frac);
a = ps->css_margin[CCPAS_LEFT];
if (a)
lwsl_notice("margin left: %d.%u\n", a->u.i.whole, a->u.i.frac);
a = ps->css_padding[CCPAS_TOP];
if (a)
lwsl_notice("padding top: %d.%u\n", a->u.i.whole, a->u.i.frac);
a = ps->css_padding[CCPAS_RIGHT];
if (a)
lwsl_notice("padding right: %d.%u\n", a->u.i.whole, a->u.i.frac);
a = ps->css_padding[CCPAS_BOTTOM];
if (a)
lwsl_notice("padding bottom: %d.%u\n", a->u.i.whole, a->u.i.frac);
a = ps->css_padding[CCPAS_LEFT];
if (a)
lwsl_notice("padding left: %d.%u\n", a->u.i.whole, a->u.i.frac);
a = lws_css_cascade_get_prop_atr(ctx, LCSP_PROP_FONT_SIZE);
if (a)
lwsl_notice("font-size: %d.%u\n", a->u.i.whole, a->u.i.frac);
a = lws_css_cascade_get_prop_atr(ctx, LCSP_PROP_FONT_FAMILY);
if (a)
lwsl_notice("font-family: %s\n", (const char *)&a[1]);
}
printf(" },\n");
#if 0
if (m < LWS_ARRAY_SIZE(rpkg)) {
if (step < rpkg[m].len) {
// lwsl_notice("test %d, step %d\n", m, step);
if (reason != rpkg[m].r[step].reason) {
lwsl_err("%s: reason mismatch %d vs %d\n", __func__, reason, rpkg[m].r[step].reason);
return -1;
}
if (ctx->ipos != rpkg[m].r[step].ipos) {
lwsl_err("%s: ipos mismatch %d vs %d\n", __func__, ctx->ipos, rpkg[m].r[step].ipos);
return -1;
}
if (ctx->ipos && memcmp(ctx->i, rpkg[m].r[step].indexes, ctx->ipos)) {
lwsl_err("%s: indexes mismatch\n", __func__);
lwsl_hexdump_err(ctx->i, ctx->ipos);
lwsl_hexdump_err(rpkg[m].r[step].indexes, ctx->ipos);
return -1;
}
if (ctx->path_match != rpkg[m].r[step].path_match) {
lwsl_err("%s: path_match mismatch %d vs %d\n", __func__, ctx->path_match, rpkg[m].r[step].path_match);
return -1;
}
if (strcmp(ctx->path, rpkg[m].r[step].path)) {
lwsl_err("%s: path mismatch '%s' vs '%s'\n", __func__, ctx->path, rpkg[m].r[step].path);
return -1;
}
if (strcmp(ctx->buf, rpkg[m].r[step].buf)) {
lwsl_err("%s: buf mismatch '%s' vs '%s'\n", __func__, ctx->buf, rpkg[m].r[step].buf);
return -1;
}
} else {
lwsl_err("%s: extra steps\n", __func__);
return -1;
}
step++;
}
#endif
return 0;
}
static const lws_surface_info_t ic = {
.wh_px = { { 600,0 }, { 448,0 } },
.wh_mm = { { 114,5000000 }, { 82,5000000 } },
};
static lws_displaylist_t displaylist;
int
main(int argc, const char **argv)
{
int e = 0, logs = LLL_USER | LLL_ERR | LLL_WARN | LLL_NOTICE;
lws_stateful_ret_t n;
lws_dl_rend_t drt;
lhp_ctx_t ctx;
const char *p;
memset(&ctx, 0, sizeof(ctx));
if ((p = lws_cmdline_option(argc, argv, "-d")))
logs = atoi(p);
lws_set_log_level(logs, NULL);
lwsl_user("LWS API selftest: lhp HTML5 parser\n");
for (m = 0; m < (int)LWS_ARRAY_SIZE(html_tests); m++) {
const uint8_t *data;
size_t size;
lwsl_user("%s: ++++++++++++++++ test %d\n", __func__, m + 1);
step = 0;
drt.dl = &displaylist;
drt.w = ic.wh_px[0].whole;
drt.h = ic.wh_px[1].whole;
if (lws_lhp_construct(&ctx, test_cb, &drt, &ic)) {
e++;
continue;
}
ctx.flags = LHP_FLAG_DOCUMENT_END;
ctx.base_url = strdup("");
data = (uint8_t *)html_tests[m];
size = strlen(html_tests[m]);
lwsl_hexdump_info(data, size);
n = lws_lhp_parse(&ctx, &data, &size);
lwsl_notice("n = %d\n", (int)n);
if (n & LWS_SRET_FATAL)
e = 1;
lws_lhp_destruct(&ctx);
}
if (e)
goto bail;
lwsl_user("Completed: PASS\n");
return 0;
bail:
lwsl_user("Completed: FAIL\n");
return 1;
}
Reference in a new issue Copy permalink