From 8bab1aaec04a3b9359eee2db1eedfe681bab43b1 Mon Sep 17 00:00:00 2001 From: Michael Drake Date: Sat, 4 Dec 2010 14:56:03 +0000 Subject: Update LibDOM example to walk though the DOM and print the DOM's structure out. Still needs to be updated to print class attribute/value when present. Also, still needs a bit of tidying and more comments. svn path=/trunk/dom/; revision=10960 --- examples/dom-structure-dump.c | 150 +++++++++++++++++++++++++++++------------- 1 file changed, 106 insertions(+), 44 deletions(-) (limited to 'examples') diff --git a/examples/dom-structure-dump.c b/examples/dom-structure-dump.c index fc1b75e..6df421f 100644 --- a/examples/dom-structure-dump.c +++ b/examples/dom-structure-dump.c @@ -7,34 +7,22 @@ */ /* - * Load an html file into libdom with hubbub and print out the dom structure + * Load an HTML file into LibDOM with Hubbub and print out the DOM structure. * - * e.g.

NetSurf

+ * This example demonstrates the following: + * + * 1. Using LibDOM's Hubbub binding to read an HTML file into LibDOM. + * 2. Walking around the DOM tree. + * 3. Accessing DOM node attributes. + * 4. Using LibWapcaplet to intern and compare strings with strings in the DOM. + * + * Example input: + *

NetSurf

NetSurf is awesome!

Hubbub

Hubbub is too.

Big time.

* - * gives: - * - * HTML - * +-BODY - * | +-H1 class="woo" - * | | +-"NetSurf" - * | +-P - * | | +-"NetSurf is " - * | | +-EM - * | | | +-"awesome" - * | | +-"!" - * | +-DIV - * | | +-H2 - * | | | +-"Hubbub" - * | | +-P - * | | | +-"Hubbub is too." - * | | +-P - * | | | +-"Big time." - * - * - * or maybe just: + * Example output: * * HTML * +-BODY @@ -90,13 +78,10 @@ void test_msg(uint32_t severity, void *ctx, const char *msg, ...) int main(int argc, char **argv) { struct test_data test_data; - lwc_error err; dom_exception exc; + lwc_error err; dom_document *doc = NULL; dom_element *root = NULL; - dom_string *root_name = NULL; - lwc_string *lwcstr = NULL; - const char *string; /* Initialise the DOM library */ exc = dom_initialise(test_realloc, &test_data); @@ -119,8 +104,9 @@ int main(int argc, char **argv) return EXIT_FAILURE; } - /* Dump DOM structure */ - /* TODO: Actually just root element for now! */ + /* + * Dump DOM structure + */ /* Get root element */ exc = dom_document_get_document_element(doc, &root); @@ -131,40 +117,116 @@ int main(int argc, char **argv) printf("Broken: root == NULL\n"); return EXIT_FAILURE; } + dump_dom_structure(root, 0); + + /* Finalise the DOM library */ + exc = dom_finalise(); + if (exc != DOM_NO_ERR) { + printf("Failed to finalise DOM library.\n"); + return EXIT_FAILURE; + } + + return EXIT_SUCCESS; +} + + +/** + * Walk though a DOM (sub)tree, in depth first order, printing DOM structure. + * + * \param node The root node to start from + * \param depth The depth of 'node' in the (sub)tree + */ +dump_dom_structure(dom_node_internal *node, int depth) +{ + dom_exception exc; + dom_node_internal *child; + + /* Print this node's entry */ + dump_dom_element(node, depth); + + /* Get the node's first child */ + exc = dom_node_get_first_child(node, &child); + if (exc != DOM_NO_ERR) { + printf("Exception raised for node_get_first_child\n"); + return EXIT_FAILURE; + } else if (child != NULL) { + /* node has children; decend to children's depth */ + depth++; + + /* Loop though all node's children */ + do { + /* Visit node's descendents */ + dump_dom_structure(child, depth); + + /* Go to next sibling */ + exc = dom_node_get_next_sibling(child, &child); + if (exc != DOM_NO_ERR) { + printf("Exception raised for " + "node_get_next_sibling\n"); + return EXIT_FAILURE; + } + } while (child != NULL); /* No more children */ + } +} + + +/** + * Print a line in a DOM structure dump for an element + * + * \param node The node to dump + * \param depth The node's depth + */ +dump_dom_element(dom_node_internal *node, int depth) +{ + dom_exception exc; + lwc_error err; + dom_string *node_name = NULL; + lwc_string *lwcstr = NULL; + const char *string; + dom_node_type type; + int i; + size_t length; + + exc = dom_node_get_node_type(node, &type); + if (exc != DOM_NO_ERR) { + printf("Exception raised for node_get_node_type\n"); + return EXIT_FAILURE; + } else if (type != DOM_ELEMENT_NODE) { + return; + } /* Get root element name */ - exc = dom_node_get_node_name(root, &root_name); + exc = dom_node_get_node_name(node, &node_name); if (exc != DOM_NO_ERR) { printf("Exception raised for get_node_name\n"); return EXIT_FAILURE; - } else if (root_name == NULL) { + } else if (node_name == NULL) { printf("Broken: root_name == NULL\n"); return EXIT_FAILURE; } - /* Get root element name's lwc_string */ - exc = dom_string_get_intern(root_name, &lwcstr); + /* Get element name's lwc_string */ + exc = dom_string_get_intern(node_name, &lwcstr); if (exc != DOM_NO_ERR) { printf("Exception raised for string_get_intern\n"); return EXIT_FAILURE; } - /* Get string data and print */ - string = lwc_string_data(lwcstr); - printf("%4s\n", string); - - /* Finalise the DOM library */ - exc = dom_finalise(); - if (exc != DOM_NO_ERR) { - printf("Failed to finalise DOM library.\n"); - return EXIT_FAILURE; + /* Print ASCII tree structure for current node */ + if (depth > 0) { + for (i = 0; i < depth; i++) { + printf("| "); + } + printf("+-"); } - return EXIT_SUCCESS; + /* Get string data and print element name */ + string = lwc_string_data(lwcstr); + length = lwc_string_length(lwcstr); + printf("%*s\n", length, string); } - /** * Generate a LibDOM document DOM from an HTML file * -- cgit v1.2.3