path: root/camel/gmime-content-field.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* mime-content_field.c : mime content type field utilities  */

/* 
 *
 * Author : 
 *  Bertrand Guiheneuf <bertrand@helixcode.com>
 *
 * Copyright 1999, 2000 Helix Code, Inc. (http://www.helixcode.com)
 *
 * This program 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; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

#include <config.h>
#include "gmime-content-field.h"
#include "string-utils.h"
#include <string.h>
#include "hash-table-utils.h"

/**
 * gmime_content_field_new: Creates a new GMimeContentField object
 * @type: mime type
 * @subtype: mime subtype 
 * 
 * Creates a GMimeContentField object and initialize it with
 * a mime type and a mime subtype. For example, 
 * gmime_content_field_new ("application", "postcript");
 * will create a content field with complete mime type 
 * "application/postscript"
 * 
 * Return value: The newly created GMimeContentField object
 **/
GMimeContentField *
gmime_content_field_new (const gchar *type, const gchar *subtype)
{
    GMimeContentField *ctf;

    ctf = g_new (GMimeContentField, 1);
    ctf->type = g_strdup (type);
    ctf->subtype = g_strdup (subtype);
    ctf->parameters = g_hash_table_new (g_strcase_hash, g_strcase_equal);
    ctf->ref = 1;

    return ctf;
} 


static void
_free_parameter (gpointer name, gpointer value, gpointer user_data)
{
    g_free (name);
    g_free (value);
}

/**
 * gmime_content_field_free: free a GMimeContentField object
 * @content_field: GMimeContentField object
 * 
 * This method destroys the object and should be used very carefully.
 * Use gmime_content_field_unref instead.
 *
 **/
void 
gmime_content_field_free (GMimeContentField *content_field)
{
    if (!content_field) return;

    g_assert (content_field->ref <= 0);

    g_hash_table_foreach (content_field->parameters, _free_parameter, NULL);
    g_free (content_field->type);
    g_free (content_field->subtype);
    g_hash_table_destroy (content_field->parameters);
    g_free (content_field);
}

/**
 * gmime_content_field_ref: add a reference to a GMimeContentField object
 * @content_field: GMimeContentField object
 * 
 * Tell a GMimeContentField object that something holds a reference
 * on him. This, coupled with the corresponding 
 * gmime_content_field_unref() method allow several 
 * objects to use the same GMimeContentField object.
 **/
void 
gmime_content_field_ref (GMimeContentField *content_field)
{
    content_field->ref += 1;
}

/**
 * gmime_content_field_unref: remove a reference to a GMimeContentField object
 * @content_field: GMimeContentField object
 * 
 * Tell a GMimeContentField object that something which 
 * was holding a reference to him does not need it anymore.
 * When no more reference exist, the GMimeContentField object
 * is freed using gmime_content_field_free().
 *
 **/
void 
gmime_content_field_unref (GMimeContentField *content_field)
{
    if (!content_field) return;
    
    content_field->ref -= 1;
    if (content_field->ref <= 0)
        gmime_content_field_free (content_field);
}



/**
 * gmime_content_field_set_parameter: set a parameter for a GMimeContentField object
 * @content_field: content field
 * @attribute: parameter name 
 * @value: paramteter value
 * 
 * set a parameter (called attribute in RFC 2045) of a content field. Meaningfull
 * or valid parameters name depend on the content type object. For example, 
 * gmime_content_field_set_parameter (cf, "charset", "us-ascii");
 * will make sense for a "text/plain" content field but not for a 
 * "image/gif". This routine does not check parameter validity.
 **/
void 
gmime_content_field_set_parameter (GMimeContentField *content_field, const gchar *attribute, const gchar *value)
{
    gboolean attribute_exists;
    gchar *old_attribute;
    gchar *old_value;
    attribute_exists = g_hash_table_lookup_extended (content_field->parameters, 
                             attribute, 
                             (gpointer *) &old_attribute,
                             (gpointer *) &old_value);
    /** CHECK THAT : is normal to free pointers before insertion ? **/
    if (attribute_exists) {
        g_hash_table_remove(content_field->parameters, attribute);
        g_free (old_value);
        g_free (old_attribute);
    } 
        
    g_hash_table_insert (content_field->parameters, g_strdup (attribute), g_strdup (value));
}


/**
 * _print_parameter: print a parameter/value pair to a stream as described in RFC 2045
 * @name: name of the parameter
 * @value: value of the parameter
 * @user_data: CamelStream object to write the text to.
 * 
 * 
 **/
static void
_print_parameter (gpointer name, gpointer value, gpointer user_data)
{
    CamelStream *stream = (CamelStream *)user_data;
    
    camel_stream_write_strings (stream, 
                    "; \n    ", 
                    (gchar *)name, 
                    "=", 
                    (gchar *)value,
                    NULL);
    
}

/**
 * gmime_content_field_write_to_stream: write a mime content type to a stream
 * @content_field: content type object
 * @stream: the stream
 * 
 * 
 **/
void
gmime_content_field_write_to_stream (GMimeContentField *content_field, CamelStream *stream)
{
    if (!content_field) return;

    g_assert (stream);
    if (content_field->type) {
        camel_stream_write_strings (stream, "Content-Type: ", content_field->type, NULL);
        if (content_field->subtype) {
            camel_stream_write_strings (stream, "/", content_field->subtype, NULL);
        }
        /* print all parameters */
        g_hash_table_foreach (content_field->parameters, _print_parameter, stream);
        camel_stream_write_string (stream, "\n");
    }
}

/**
 * gmime_content_field_get_mime_type: return the mime type of the content field object
 * @content_field: content field object
 * 
 * A RFC 2045 content type field contains the mime type in the
 * form "type/subtype" (example : "application/postscript") and some
 * parameters (attribute/value pairs). This routine returns the mime type 
 * in a gchar object. THIS OBJECT MUST BE FREED BY THE CALLER.
 * 
 * Return value: the mime type in the form "type/subtype" or NULL if not defined.
 **/
gchar * 
gmime_content_field_get_mime_type (GMimeContentField *content_field)
{
    gchar *mime_type;

    if (!content_field->type) return NULL;

    if (content_field->subtype) 
        mime_type = g_strdup_printf ("%s/%s", content_field->type, content_field->subtype);
    else 
        mime_type = g_strdup (content_field->type);
    return mime_type;
}

static void
___debug_print_parameter (gpointer name, gpointer value, gpointer user_data)
{
    
    printf ("****** parameter \"%s\"=\"%s\"\n", (gchar *)name, (gchar *)value);
    
}

/**
 * gmime_content_field_get_parameter: return the value of a mime type parameter
 * @content_field: content field object
 * @name: name of the parameter
 * 
 * Returns the value of a parameter contained in the content field 
 * object. The content type is formed of a mime type, a mime subtype,
 * and a parameter list. Each parameter is a name/value pair. This 
 * routine returns the value assiciated to a given name. 
 * When the parameter does not exist, NULL is returned. 
 * 
 * Return value: parameter value, or NULL if not found.
 **/
const gchar *
gmime_content_field_get_parameter (GMimeContentField *content_field, const gchar *name)
{
    const gchar *parameter;
    const gchar *old_name;
    gboolean parameter_exists;

    g_assert (content_field->parameters);
    g_assert (name);
    /* parameter = (const gchar *)g_hash_table_lookup (content_field->parameters, name); */
    parameter_exists = g_hash_table_lookup_extended (content_field->parameters, 
                             name, 
                             (gpointer *) &old_name,
                             (gpointer *) &parameter);
    if (!parameter_exists) {
        g_hash_table_foreach (content_field->parameters, ___debug_print_parameter, NULL);
        return NULL;
    }
    return parameter;
}




/**
 * gmime_content_field_construct_from_string: construct a ContentType object by parsing a string.
 *
 * @content_field: content type object to construct 
 * @string: string containing the content type field 
 * 
 * Parse a string containing a content type field as defined in
 * RFC 2045, and construct the corresponding ContentType object.
 * The string is not modified and not used in the ContentType 
 * object. It can and must be freed by the calling part.
 **/
void
gmime_content_field_construct_from_string (GMimeContentField *content_field, const gchar *string)
{
    gint first, len;
    gint i=0;
    gchar *type, *subtype;
    gchar *param_name, *param_value;
    gboolean param_end;
    
    g_assert (string);
    g_assert (content_field);
 
    g_free (content_field->type);   
    g_free (content_field->subtype);
    
    
    first = 0;
    len = strlen (string);
    if (!len)
        return;

    /* find the type */
    while ( (i<len) && (!strchr ("/;", string[i])) ) i++;
    
    if (i == 0)
        return;
    
    type = g_strndup (string, i);
    string_trim (type, " \t\"", STRING_TRIM_STRIP_TRAILING | STRING_TRIM_STRIP_LEADING);
    content_field->type = type;
    if (i >= len-1) {
        content_field->subtype = NULL;
        return;         
    }
    
    first = i+1;
    /* find the subtype, if any */
    if (string[i++] == '/') {
        while ( (i<len) && (string[i] != ';') ) i++;
        if (i != first) {
            subtype = g_strndup (string+first, i-first);
            string_trim (subtype, " \t\"", STRING_TRIM_STRIP_TRAILING | STRING_TRIM_STRIP_LEADING);
            content_field->subtype = subtype;
            if (i >= len-1)
                return;
        }
    }
    first = i+1;

    /* parse parameters list */
    param_end = FALSE;
    do {
        while ( (i<len) && (string[i] != '=') ) i++;
        if ((i == len) || (i==first)) param_end = TRUE;
        else {
            /* we have found parameter name */
            param_name = g_strndup (string+first, i-first);
            string_trim (param_name, " \"", STRING_TRIM_STRIP_TRAILING | STRING_TRIM_STRIP_LEADING);
            i++;
            first = i;
            /* Let's find parameter value */
            while ( (i<len) && (string[i] != ';') ) i++;
            if (i != first) param_value = g_strndup (string+first, i-first);
            else param_value = g_strdup ("");
            string_trim (param_value, " \t\"", STRING_TRIM_STRIP_TRAILING | STRING_TRIM_STRIP_LEADING);
            gmime_content_field_set_parameter (content_field, param_name, param_value);
            g_free (param_name);
            g_free (param_value);
            i++;
            first = i;
        }
    } while ((!param_end) && (first < len));


}