forms.c

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/*
 * Copyright 2011 Vincent Sanders <vince@netsurf-browser.org>
 *
 * This file is part of NetSurf, http://www.netsurf-browser.org/
 *
 * NetSurf is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * NetSurf is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
/**
 * \file
 * HTML form handling implementation
 */
 
#include <string.h>
 
#include "utils/config.h"
#include "utils/corestrings.h"
#include "utils/log.h"
 
#include "html/form_internal.h"
#include "html/private.h"
 
/**
 * process form element from dom
 */
static struct form *
parse_form_element(const char *docenc, dom_node *node)
{
        dom_string *ds_action = NULL;
        dom_string *ds_charset = NULL;
        dom_string *ds_target = NULL;
        dom_string *ds_method = NULL;
        dom_string *ds_enctype = NULL;
        char *action = NULL, *charset = NULL, *target = NULL;
        form_method method;
        dom_html_form_element *formele = (dom_html_form_element *)(node);
        struct form * ret = NULL;
 
        /* Retrieve the attributes from the node */
        if (dom_html_form_element_get_action(formele,
                        &ds_action) != DOM_NO_ERR)
                goto out;
 
        if (dom_html_form_element_get_accept_charset(formele,
                        &ds_charset) != DOM_NO_ERR)
                goto out;
 
        if (dom_html_form_element_get_target(formele,
                        &ds_target) != DOM_NO_ERR)
                goto out;
 
        if (dom_html_form_element_get_method(formele,
                        &ds_method) != DOM_NO_ERR)
                goto out;
 
        if (dom_html_form_element_get_enctype(formele,
                        &ds_enctype) != DOM_NO_ERR)
                goto out;
 
        /* Extract the plain attributes ready for use.  We have to do this
         * because we cannot guarantee that the dom_strings are NULL terminated
         * and thus we copy them.
         */
        if (ds_action != NULL)
                action = strndup(dom_string_data(ds_action),
                                 dom_string_byte_length(ds_action));
 
        if (ds_charset != NULL)
                charset = strndup(dom_string_data(ds_charset),
                                  dom_string_byte_length(ds_charset));
 
        if (ds_target != NULL)
                target = strndup(dom_string_data(ds_target),
                                 dom_string_byte_length(ds_target));
 
        /* Determine the method */
        method = method_GET;
        if (ds_method != NULL) {
                if (dom_string_caseless_lwc_isequal(ds_method,
                                corestring_lwc_post)) {
                        method = method_POST_URLENC;
                        if (ds_enctype != NULL) {
                                if (dom_string_caseless_lwc_isequal(ds_enctype,
                                        corestring_lwc_multipart_form_data)) {
 
                                        method = method_POST_MULTIPART;
                                }
                        }
                }
        }
 
        /* Construct the form object */
        ret = form_new(node, action, target, method, charset, docenc);
 
out:
        if (ds_action != NULL)
                dom_string_unref(ds_action);
        if (ds_charset != NULL)
                dom_string_unref(ds_charset);
        if (ds_target != NULL)
                dom_string_unref(ds_target);
        if (ds_method != NULL)
                dom_string_unref(ds_method);
        if (ds_enctype != NULL)
                dom_string_unref(ds_enctype);
        if (action != NULL)
                free(action);
        if (charset != NULL)
                free(charset);
        if (target != NULL)
                free(target);
        return ret;
}
 
/* documented in html_internal.h */
struct form *html_forms_get_forms(const char *docenc, dom_html_document *doc)
{
        dom_html_collection *forms;
        struct form *ret = NULL, *newf;
        dom_node *node;
        unsigned long n;
        uint32_t nforms;
 
        if (doc == NULL)
                return NULL;
 
        /* Attempt to build a set of all the forms */
        if (dom_html_document_get_forms(doc, &forms) != DOM_NO_ERR)
                return NULL;
 
        /* Count the number of forms so we can iterate */
        if (dom_html_collection_get_length(forms, &nforms) != DOM_NO_ERR)
                goto out;
 
        /* Iterate the forms collection, making form structs for returning */
        for (n = 0; n < nforms; ++n) {
                if (dom_html_collection_item(forms, n, &node) != DOM_NO_ERR) {
                        goto out;
                }
                newf = parse_form_element(docenc, node);
                dom_node_unref(node);
                if (newf == NULL) {
                        goto err;
                }
                newf->prev = ret;
                ret = newf;
        }
 
        /* All went well */
        goto out;
err:
        while (ret != NULL) {
                struct form *prev = ret->prev;
                /* Destroy ret */
                free(ret);
                ret = prev;
        }
out:
        /* Finished with the collection, return it */
        dom_html_collection_unref(forms);
 
        return ret;
}
 
static struct form *
find_form(struct form *forms, dom_html_form_element *form)
{
        while (forms != NULL) {
                if (forms->node == form)
                        break;
                forms = forms->prev;
        }
 
        return forms;
}
 
static struct form_control *
parse_button_element(struct form *forms, dom_html_button_element *button)
{
        struct form_control *control = NULL;
        dom_exception err;
        dom_html_form_element *form = NULL;
        dom_string *ds_type = NULL;
        dom_string *ds_value = NULL;
        dom_string *ds_name = NULL;
 
        err = dom_html_button_element_get_form(button, &form);
        if (err != DOM_NO_ERR)
                goto out;
 
        err = dom_html_button_element_get_type(button, &ds_type);
        if (err != DOM_NO_ERR)
                goto out;
 
        if (ds_type == NULL) {
                control = form_new_control(button, GADGET_SUBMIT);
        } else {
                if (dom_string_caseless_lwc_isequal(ds_type,
                                corestring_lwc_submit)) {
                        control = form_new_control(button, GADGET_SUBMIT);
                } else if (dom_string_caseless_lwc_isequal(ds_type,
                                corestring_lwc_reset)) {
                        control = form_new_control(button, GADGET_RESET);
                } else {
                        control = form_new_control(button, GADGET_BUTTON);
                }
        }
 
        if (control == NULL)
                goto out;
 
        err = dom_html_button_element_get_value(button, &ds_value);
        if (err != DOM_NO_ERR)
                goto out;
        err = dom_html_button_element_get_name(button, &ds_name);
        if (err != DOM_NO_ERR)
                goto out;
 
        if (ds_value != NULL) {
                control->value = strndup(
                        dom_string_data(ds_value),
                        dom_string_byte_length(ds_value));
 
                if (control->value == NULL) {
                        form_free_control(control);
                        control = NULL;
                        goto out;
                }
        }
 
        if (ds_name != NULL) {
                control->name = strndup(
                        dom_string_data(ds_name),
                        dom_string_byte_length(ds_name));
 
                if (control->name == NULL) {
                        form_free_control(control);
                        control = NULL;
                        goto out;
                }
        }
 
        if (form != NULL && control != NULL)
                form_add_control(find_form(forms, form), control);
 
out:
        if (form != NULL)
                dom_node_unref(form);
        if (ds_type != NULL)
                dom_string_unref(ds_type);
        if (ds_value != NULL)
                dom_string_unref(ds_value);
        if (ds_name != NULL)
                dom_string_unref(ds_name);
 
        return control;
}
 
static struct form_control *
parse_input_element(struct form *forms, dom_html_input_element *input)
{
        struct form_control *control = NULL;
        dom_html_form_element *form = NULL;
        dom_string *ds_type = NULL;
        dom_string *ds_name = NULL;
        dom_string *ds_value = NULL;
 
        char *name = NULL;
 
        if (dom_html_input_element_get_form(input, &form) != DOM_NO_ERR)
                goto out;
 
        if (dom_html_input_element_get_type(input, &ds_type) != DOM_NO_ERR)
                goto out;
 
        if (dom_html_input_element_get_name(input, &ds_name) != DOM_NO_ERR)
                goto out;
 
        if (ds_name != NULL)
                name = strndup(dom_string_data(ds_name),
                               dom_string_byte_length(ds_name));
 
        if (ds_type != NULL && dom_string_caseless_lwc_isequal(ds_type,
                        corestring_lwc_password)) {
                control = form_new_control(input, GADGET_PASSWORD);
        } else if (ds_type != NULL && dom_string_caseless_lwc_isequal(ds_type,
                        corestring_lwc_file)) {
                control = form_new_control(input, GADGET_FILE);
        } else if (ds_type != NULL && dom_string_caseless_lwc_isequal(ds_type,
                        corestring_lwc_hidden)) {
                control = form_new_control(input, GADGET_HIDDEN);
        } else if (ds_type != NULL && dom_string_caseless_lwc_isequal(ds_type,
                        corestring_lwc_checkbox)) {
                control = form_new_control(input, GADGET_CHECKBOX);
        } else if (ds_type != NULL && dom_string_caseless_lwc_isequal(ds_type,
                        corestring_lwc_radio)) {
                control = form_new_control(input, GADGET_RADIO);
        } else if (ds_type != NULL && dom_string_caseless_lwc_isequal(ds_type,
                        corestring_lwc_submit)) {
                control = form_new_control(input, GADGET_SUBMIT);
        } else if (ds_type != NULL && dom_string_caseless_lwc_isequal(ds_type,
                        corestring_lwc_reset)) {
                control = form_new_control(input, GADGET_RESET);
        } else if (ds_type != NULL && dom_string_caseless_lwc_isequal(ds_type,
                        corestring_lwc_button)) {
                control = form_new_control(input, GADGET_BUTTON);
        } else if (ds_type != NULL && dom_string_caseless_lwc_isequal(ds_type,
                        corestring_lwc_image)) {
                control = form_new_control(input, GADGET_IMAGE);
        } else {
                control = form_new_control(input, GADGET_TEXTBOX);
        }
 
        if (control == NULL)
                goto out;
 
        if (name != NULL) {
                /* Hand the name string over */
                control->name = name;
                name = NULL;
        }
 
        if (control->type == GADGET_CHECKBOX || control->type == GADGET_RADIO) {
                bool selected;
                if (dom_html_input_element_get_checked(
                            input, &selected) == DOM_NO_ERR) {
                        control->selected = selected;
                }
        }
 
        if (control->type == GADGET_PASSWORD ||
            control->type == GADGET_TEXTBOX) {
                int32_t maxlength;
                if (dom_html_input_element_get_max_length(
                            input, &maxlength) != DOM_NO_ERR) {
                        maxlength = -1;
                }
 
                if (maxlength >= 0) {
                        /* Got valid maxlength */
                        control->maxlength = maxlength;
                } else {
                        /* Input has no maxlength attr, or
                         * dom_html_input_element_get_max_length failed.
                         *
                         * Set it to something insane. */
                        control->maxlength = UINT_MAX;
                }
        }
 
        if (control->type != GADGET_FILE && control->type != GADGET_IMAGE) {
                if (dom_html_input_element_get_value(
                            input, &ds_value) == DOM_NO_ERR) {
                        if (ds_value != NULL) {
                                control->value = strndup(
                                        dom_string_data(ds_value),
                                        dom_string_byte_length(ds_value));
                                if (control->value == NULL) {
                                        form_free_control(control);
                                        control = NULL;
                                        goto out;
                                }
                                control->length = strlen(control->value);
                        }
                }
 
                if (control->type == GADGET_TEXTBOX ||
                                control->type == GADGET_PASSWORD) {
                        if (control->value == NULL) {
                                control->value = strdup("");
                                if (control->value == NULL) {
                                        form_free_control(control);
                                        control = NULL;
                                        goto out;
                                }
 
                                control->length = 0;
                        }
 
                        control->initial_value = strdup(control->value);
                        if (control->initial_value == NULL) {
                                form_free_control(control);
                                control = NULL;
                                goto out;
                        }
 
                        control->last_synced_value = strdup(control->value);
                        if (control->last_synced_value == NULL) {
                                form_free_control(control);
                                control = NULL;
                                goto out;
                        }
 
                        control->node_value = dom_string_ref(ds_value);
                }
                /* Force the gadget and DOM to be in sync */
                form_gadget_sync_with_dom(control);
        }
 
        if (form != NULL && control != NULL)
                form_add_control(find_form(forms, form), control);
 
out:
        if (form != NULL)
                dom_node_unref(form);
        if (ds_type != NULL)
                dom_string_unref(ds_type);
        if (ds_name != NULL)
                dom_string_unref(ds_name);
        if (ds_value != NULL)
                dom_string_unref(ds_value);
 
        if (name != NULL)
                free(name);
 
        return control;
}
 
static struct form_control *
parse_textarea_element(struct form *forms, dom_html_text_area_element *ta)
{
        struct form_control *control = NULL;
        dom_html_form_element *form = NULL;
        dom_string *ds_name = NULL;
 
        char *name = NULL;
 
        if (dom_html_text_area_element_get_form(ta, &form) != DOM_NO_ERR)
                goto out;
 
        if (dom_html_text_area_element_get_name(ta, &ds_name) != DOM_NO_ERR)
                goto out;
 
        if (ds_name != NULL)
                name = strndup(dom_string_data(ds_name),
                               dom_string_byte_length(ds_name));
 
        control = form_new_control(ta, GADGET_TEXTAREA);
 
        if (control == NULL)
                goto out;
 
        if (name != NULL) {
                /* Hand the name string over */
                control->name = name;
                name = NULL;
        }
 
        if (form != NULL && control != NULL)
                form_add_control(find_form(forms, form), control);
 
out:
        if (form != NULL)
                dom_node_unref(form);
        if (ds_name != NULL)
                dom_string_unref(ds_name);
 
        if (name != NULL)
                free(name);
 
 
        return control;
}
 
static struct form_control *
parse_select_element(struct form *forms, dom_html_select_element *select)
{
        struct form_control *control = NULL;
        dom_html_form_element *form = NULL;
        dom_string *ds_name = NULL;
 
        char *name = NULL;
 
        if (dom_html_select_element_get_form(select, &form) != DOM_NO_ERR)
                goto out;
 
        if (dom_html_select_element_get_name(select, &ds_name) != DOM_NO_ERR)
                goto out;
 
        if (ds_name != NULL)
                name = strndup(dom_string_data(ds_name),
                               dom_string_byte_length(ds_name));
 
        control = form_new_control(select, GADGET_SELECT);
 
        if (control == NULL)
                goto out;
 
        if (name != NULL) {
                /* Hand the name string over */
                control->name = name;
                name = NULL;
        }
 
        dom_html_select_element_get_multiple(select,
                        &(control->data.select.multiple));
 
        if (form != NULL && control != NULL)
                form_add_control(find_form(forms, form), control);
 
out:
        if (form != NULL)
                dom_node_unref(form);
        if (ds_name != NULL)
                dom_string_unref(ds_name);
 
        if (name != NULL)
                free(name);
 
 
        return control;
}
 
 
static struct form_control *
invent_fake_gadget(dom_node *node)
{
        struct form_control *ctl = form_new_control(node, GADGET_HIDDEN);
        if (ctl != NULL) {
                ctl->value = strdup("");
                ctl->initial_value = strdup("");
                ctl->name = strdup("foo");
 
                if (ctl->value == NULL || ctl->initial_value == NULL ||
                                ctl->name == NULL) {
                        form_free_control(ctl);
                        ctl = NULL;
                }
        }
        return ctl;
}
 
/* documented in html_internal.h */
struct form_control *
html_forms_get_control_for_node(struct form *forms, dom_node *node)
{
        struct form *f;
        struct form_control *ctl = NULL;
        dom_exception err;
        dom_string *ds_name = NULL;
 
        /* Step one, see if we already have a control */
        for (f = forms; f != NULL; f = f->prev) {
                for (ctl = f->controls; ctl != NULL; ctl = ctl->next) {
                        if (ctl->node == node)
                                return ctl;
                }
        }
 
        /* Step two, extract the node's name so we can construct a gadget. */
        err = dom_element_get_tag_name(node, &ds_name);
        if (err == DOM_NO_ERR && ds_name != NULL) {
 
                /* Step three, attempt to work out what gadget to make */
                if (dom_string_caseless_lwc_isequal(ds_name,
                                corestring_lwc_button)) {
                        ctl = parse_button_element(forms,
                                        (dom_html_button_element *) node);
                } else if (dom_string_caseless_lwc_isequal(ds_name,
                                corestring_lwc_input)) {
                        ctl = parse_input_element(forms,
                                        (dom_html_input_element *) node);
                } else if (dom_string_caseless_lwc_isequal(ds_name,
                                corestring_lwc_textarea)) {
                        ctl = parse_textarea_element(forms,
                                        (dom_html_text_area_element *) node);
                } else if (dom_string_caseless_lwc_isequal(ds_name,
                                corestring_lwc_select)) {
                        ctl = parse_select_element(forms,
                                        (dom_html_select_element *) node);
                }
        }
 
        /* If all else fails, fake gadget time */
        if (ctl == NULL)
                ctl = invent_fake_gadget(node);
 
        if (ds_name != NULL)
                dom_string_unref(ds_name);
 
        return ctl;
}