added DataField::getCount(), exclude name wrap when fieldIndex is used in SingleDataField::read(), corrected json indent

src/lib/ebus/data.h

@@ -249,6 +249,12 @@ class DataField : public AttributedItem {
       const map<unsigned int, string>& values, map<string, string>* attributes,
       vector<const SingleDataField*>* fields) const = 0;
 
+  /**
+   * Get the field count (excluding ignored fields).
+   * @return the field count (excluding ignored fields).
+   */
+  virtual size_t getCount() const = 0;
+
   /**
    * Get the specified field name.
    * @param fieldIndex the index of the field (excluding ignored fields), or -1 for this.
@@ -392,6 +398,9 @@ class SingleDataField : public DataField {
    */
   bool hasFullByteOffset(bool after) const;
 
+  // @copydoc
+  size_t getCount() const override { return isIgnored() ? 0 : 1; }
+
   // @copydoc
   virtual string getName(ssize_t fieldIndex) const {
     return isIgnored() || fieldIndex > 0 ? "" : m_name;
@@ -628,6 +637,9 @@ class DataFieldSet : public DataField {
   // @copydoc
   size_t getLength(PartType partType, size_t maxLength) const override;
 
+  // @copydoc
+  size_t getCount() const override { return m_fields.size() - m_ignoredCount; }
+
   // @copydoc
   string getName(ssize_t fieldIndex) const override;