Ejemplo n.º 1
0
 /// <summary>
 /// Gets the renderer that can render an assessmentItem.
 /// </summary>
 /// <param name="assessmentItem">The assessment item to render. This is the &lt;img&gt; element that is in 
 /// the original LRM content.</param>
 /// <remarks>RenderContext must have been set prior to calling this method.</remarks>
 internal AssessmentItemRenderer GetRenderer(AssessmentItem assessmentItem)
 {
     AssessmentItemRenderer renderer = m_renderers[assessmentItem.Type];
     renderer.AssessmentItem = assessmentItem;
     return renderer;
 }
Ejemplo n.º 2
0
        /// <summary>
        /// Use an assessmentItem from an LRM page.htm to create an AssessmentItem object. 
        /// </summary>
        /// <param name="assessmentItem">The src attribute value of the img tag that corresponds to the assessment item.</param>
        /// <returns>The object representing the parsed value.</returns>
        /// <remarks>
        /// If more than one of the same name/value pairs exists with the same name, only the first is used.
        /// </remarks>
        /// <exception cref="FormatException">Thrown if the <paramref name="assessmentItem"/> cannot be parsed.</exception>
        public static AssessmentItem Parse(string assessmentItem)
        {
            AIResources.Culture = LocalizationManager.GetCurrentCulture();

            // assessmentItem contains the value of the src attribute, which is of the form:
            // "http://localhost:3535/mslamrk,type=1,id=3,cols=10,akey=over,uak=0".
            // Split this string by the ',' character.
            string[] commaSplit = assessmentItem.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
            Dictionary<string, string> parsedValues = new Dictionary<string, string>(10);
            foreach (string pair in commaSplit)
            {
                string[] equalSplit = pair.Split(new char[] { '=' }, 2, StringSplitOptions.None);
                if (equalSplit.Length == 2) // gets rid of the "protocol://server/mslamrk" portion, and any non-value markup
                {
                    // convert id to all upper case
                    string id = equalSplit[0].ToUpperInvariant();
                    if (!parsedValues.ContainsKey(id))
                    {
                        parsedValues.Add(id, equalSplit[1]);
                    }
                }
            }

            // if (id contains invalid values per LRDG) throw FormatException.  id is required.
            if (!parsedValues.ContainsKey(AiStrings.Id) || !IsLegalId(parsedValues[AiStrings.Id]))
            {
                throw new FormatException(String.Format(CultureInfo.InvariantCulture, AIResources.InvalidId, assessmentItem));
            }

            // if (there is no type value) throw FormatException.  see switch statement below.
            if (!parsedValues.ContainsKey(AiStrings.Type))
            {
                throw new FormatException(String.Format(CultureInfo.InvariantCulture, AIResources.InvalidType, assessmentItem));
            }

            // if other values are not correct (eg, rows is not numeric) then just ignore the invalid values 
            // and 'be nice' about returning defaults that are appropriate for the type.
            AssessmentItem item = new AssessmentItem();
            item.m_id = parsedValues[AiStrings.Id]; // id is valid because of above check
            switch(parsedValues[AiStrings.Type]) // type is valid because of above check
            {
                default:
                    // If the type is not one of the cases, it is an invalid value.
                    throw new FormatException(String.Format(CultureInfo.InvariantCulture, AIResources.InvalidType, assessmentItem));
                case "1":
                    item.m_type = AssessmentItemType.Text;
                    item.m_cols = GetCols(parsedValues);
                    if (parsedValues.ContainsKey(AiStrings.Akey)) // optional argument
                    {
                        item.m_akey = LrdgDecodeString(parsedValues[AiStrings.Akey]); // optional argument
                        // according the LRDG, uak can be "0" or "1", and if it exists then
                        // akey must exist.  Here, if uak exists but akey doesn't, uak is never
                        // parsed.  Also, if uak exists but is anything other than "0" it is
                        // assumed to be "1" by default.
                        if (parsedValues.ContainsKey(AiStrings.Uak))
                        {
                            if (parsedValues[AiStrings.Uak] == "0") item.m_uak = false;
                            else item.m_uak = true;
                        }
                    }
                    else
                    {
                        item.m_akey = String.Empty;
                    }
                    break;
                case "2":
                    item.m_type = AssessmentItemType.TextArea;
                    item.m_cols = GetCols(parsedValues);
                    int rows;
                    if (parsedValues.ContainsKey(AiStrings.Rows)
                        && Int32.TryParse(parsedValues[AiStrings.Rows], NumberStyles.Integer, CultureInfo.InvariantCulture, out rows))
                    {
                        item.m_rows = rows;
                    }
                    else item.m_rows = 5;
                    break;
                case "3":
                    item.m_type = AssessmentItemType.Radio;
                    item.m_maxPts = GetMaxPts(parsedValues);
                    break;
                case "4":
                    item.m_type = AssessmentItemType.Checkbox;
                    item.m_maxPts = GetMaxPts(parsedValues);
                    break;
                case "5":
                    item.m_type = AssessmentItemType.ItemScore;
                    item.m_maxPts = GetMaxPts(parsedValues);
                    break;
                case "7":
                    item.m_type = AssessmentItemType.Select;
                    if (parsedValues.ContainsKey(AiStrings.Text))
                    {
                        item.m_text = LrdgDecodeString(parsedValues[AiStrings.Text]);
                    }
                    else
                    {
                        item.m_text = String.Empty;
                    }
                    break;
                case "8":
                    item.m_type = AssessmentItemType.Rubric;
                    item.m_maxPts = GetMaxPts(parsedValues);
                    break;
                case "9":
                    item.m_type = AssessmentItemType.File;
                    item.m_cols = GetCols(parsedValues);
                    break;
            }
            return item;
        }