jdatadecode.m

function newdata=jdatadecode(data,varargin)
%
% newdata=jdatadecode(data,opt,...)
%
% Convert all JData object (in the form of a struct array) into an array
% (accepts JData objects loaded from either loadjson/loadubjson or 
% jsondecode for MATLAB R2018a or later)
%
% This function implements the JData Specification Draft 2 (Oct. 2019)
% see http://github.com/fangq/jdata for details
%
% authors:Qianqian Fang (q.fang <at> neu.edu)
%
% input:
%      data: a struct array. If data contains JData keywords in the first
%            level children, these fields are parsed and regrouped into a
%            data object (arrays, trees, graphs etc) based on JData 
%            specification. The JData keywords are
%               "_ArrayType_", "_ArraySize_", "_ArrayData_"
%               "_ArrayIsSparse_", "_ArrayIsComplex_", 
%               "_ArrayZipType_", "_ArrayZipSize", "_ArrayZipData_"
%      opt: (optional) a list of 'Param',value pairs for additional options 
%           The supported options include
%               Recursive: [1|0] if set to 1, will apply the conversion to 
%                            every child; 0 to disable
%               Base64: [0|1] if set to 1, _ArrayZipData_ is assumed to
%                         be encoded with base64 format and need to be
%                         decoded first. This is needed for JSON but not
%                         UBJSON data
%               Prefix: ['x0x5F'|'x'] for JData files loaded via loadjson/loadubjson, the
%                         default JData keyword prefix is 'x0x5F'; if the
%                         json file is loaded using matlab2018's
%                         jsondecode(), the prefix is 'x'; this function
%                         attempts to automatically determine the prefix;
%                         for octave, the default value is an empty string ''.
%               FormatVersion: [2|float]: set the JSONLab output version; 
%                         since v2.0, JSONLab uses JData specification Draft 1
%                         for output format, it is incompatible with all
%                         previous releases; if old output is desired,
%                         please set FormatVersion to 1
%
% output:
%      newdata: the covnerted data if the input data does contain a JData 
%               structure; otherwise, the same as the input.
%
% examples:
%      obj={[],{'test'},true,struct('sparse',sparse(2,3),'magic',uint8(magic(5)))}
%      jdata=jdatadecode(jdataencode(obj))
%      isequaln(obj,jdata)
%
% license:
%     BSD or GPL version 3, see LICENSE_{BSD,GPLv3}.txt files for details 
%
% -- this function is part of JSONLab toolbox (http://iso2mesh.sf.net/cgi-bin/index.cgi?jsonlab)
%

    newdata=data;
    opt=struct;
    if(nargin==2)
        opt=varargin{1};
    elseif(nargin>2)
        opt=varargin2struct(varargin{:});
    end

    %% process non-structure inputs
    if(~isstruct(data))
        if(iscell(data))
            newdata=cellfun(@(x) jdatadecode(x,opt),data,'UniformOutput',false);
        elseif(isa(data,'containers.Map'))
            newdata=containers.Map('KeyType',data.KeyType,'ValueType','any');
            names=data.keys;
            for i=1:length(names)
                newdata(names{i})=jdatadecode(data(names{i}),opt);
            end
        end
        return;
    end
    
    %% assume the input is a struct below
    fn=fieldnames(data);
    len=length(data);
    needbase64=jsonopt('Base64',0,opt);
    format=jsonopt('FormatVersion',2,opt);
    if(isoctavemesh)
        prefix=jsonopt('Prefix','',opt);
    else
        prefix=jsonopt('Prefix','x0x5F',opt);
    end
    if(~isfield(data,N_('_ArrayType_')) && isfield(data,'x_ArrayType_'))
        prefix='x';
        opt.prefix='x';
    end

    %% recursively process subfields
    if(jsonopt('Recursive',1,opt)==1)
      for i=1:length(fn) % depth-first
        for j=1:len
            if(isstruct(data(j).(fn{i})) || isa(data(j).(fn{i}),'containers.Map'))
                newdata(j).(fn{i})=jdatadecode(data(j).(fn{i}),opt);
            elseif(iscell(data(j).(fn{i})))
                newdata(j).(fn{i})=cellfun(@(x) jdatadecode(x,opt),newdata(j).(fn{i}),'UniformOutput',false);
            end
        end
      end
    end

    %% handle array data
    if(isfield(data,N_('_ArrayType_')) && (isfield(data,N_('_ArrayData_')) || isfield(data,N_('_ArrayZipData_'))))
      newdata=cell(len,1);
      for j=1:len
        if(isfield(data,N_('_ArrayZipSize_')) && isfield(data,N_('_ArrayZipData_')))
            zipmethod='zip';
            if(isfield(data,N_('_ArrayZipType_')))
                zipmethod=data(j).(N_('_ArrayZipType_'));
            end
            if(~isempty(strmatch(zipmethod,{'zlib','gzip','lzma','lzip','lz4','lz4hc'})))
                decompfun=str2func([zipmethod 'decode']);
                if(needbase64)
                    ndata=reshape(typecast(decompfun(base64decode(data(j).(N_('_ArrayZipData_')))),data(j).(N_('_ArrayType_'))),data(j).(N_('_ArrayZipSize_'))(:)');
                else
                    ndata=reshape(typecast(decompfun(data(j).(N_('_ArrayZipData_'))),data(j).(N_('_ArrayType_'))),data(j).(N_('_ArrayZipSize_'))(:)');
                end
            else
                error('compression method is not supported');
            end
        else
            if(iscell(data(j).(N_('_ArrayData_'))))
                data(j).(N_('_ArrayData_'))=cell2mat(cellfun(@(x) double(x(:)),data(j).(N_('_ArrayData_')),'uniformoutput',0)).';
            end
            ndata=cast(data(j).(N_('_ArrayData_')),char(data(j).(N_('_ArrayType_'))));
        end
        if(isfield(data,N_('_ArrayZipSize_')))
            ndata=reshape(ndata(:),fliplr(data(j).(N_('_ArrayZipSize_'))(:)'));
            ndata=permute(ndata,ndims(ndata):-1:1);
        end
        iscpx=0;
        if(isfield(data,N_('_ArrayIsComplex_')))
            if(data(j).(N_('_ArrayIsComplex_')))
               iscpx=1;
            end
        end
        if(isfield(data,N_('_ArrayIsSparse_')) && data(j).(N_('_ArrayIsSparse_')))
                if(isfield(data,N_('_ArraySize_')))
                    dim=double(data(j).(N_('_ArraySize_'))(:)');
                    if(iscpx)
                        ndata(end-1,:)=complex(ndata(end-1,:),ndata(end,:));
                    end
                    if isempty(ndata)
                        % All-zeros sparse
                        ndata=sparse(dim(1),prod(dim(2:end)));
                    elseif dim(1)==1
                        % Sparse row vector
                        ndata=sparse(1,ndata(1,:),ndata(2,:),dim(1),prod(dim(2:end)));
                    elseif dim(2)==1
                        % Sparse column vector
                        ndata=sparse(ndata(1,:),1,ndata(2,:),dim(1),prod(dim(2:end)));
                    else
                        % Generic sparse array.
                        ndata=sparse(ndata(1,:),ndata(2,:),ndata(3,:),dim(1),prod(dim(2:end)));
                    end
                else
                    if(iscpx && size(ndata,2)==4)
                        ndata(3,:)=complex(ndata(3,:),ndata(4,:));
                    end
                    ndata=sparse(ndata(1,:),ndata(2,:),ndata(3,:));
                end
        elseif(isfield(data,N_('_ArraySize_')))
            if(iscpx)
                ndata=complex(ndata(1,:),ndata(2,:));
            end
            if(format>1.9)
                data(j).(N_('_ArraySize_'))=data(j).(N_('_ArraySize_'))(end:-1:1);
            end
            dims=data(j).(N_('_ArraySize_'))(:)';
            ndata=reshape(ndata(:),dims(:)');
            if(format>1.9)
                ndata=permute(ndata,ndims(ndata):-1:1);
            end
        end
        newdata{j}=ndata;
      end
      if(len==1)
          newdata=newdata{1};
      end
    end

    %% handle table data
    if(isfield(data,N_('_TableRecords_')))
        newdata=cell(len,1);
        for j=1:len
            ndata=data(j).(N_('_TableRecords_'));
            if(iscell(ndata))
                rownum=length(ndata);
                colnum=length(ndata{1});
                nd=cell(rownum, colnum);
                for i1=1:rownum;
                    for i2=1:colnum
                        nd{i1,i2}=ndata{i1}{i2};
                    end
                end
                newdata{j}=cell2table(nd);
            else
                newdata{j}=array2table(ndata);
            end
            if(isfield(data(j),N_('_TableRows_'))&& ~isempty(data(j).(N_('_TableRows_'))))
                newdata{j}.Properties.RowNames=data(j).(N_('_TableRows_'))(:);
            end
            if(isfield(data(j),N_('_TableCols_')) && ~isempty(data(j).(N_('_TableCols_'))))
                newdata{j}.Properties.VariableNames=data(j).(N_('_TableCols_'));
            end
        end
        if(len==1)
            newdata=newdata{1};
        end
    end

    %% handle map data
    if(isfield(data,N_('_MapData_')))
        newdata=cell(len,1);
        for j=1:len
            key=cell(1,length(data(j).(N_('_MapData_'))));
            val=cell(size(key));
            for k=1:length(data(j).(N_('_MapData_')))
                key{k}=data(j).(N_('_MapData_')){k}{1};
                val{k}=jdatadecode(data(j).(N_('_MapData_')){k}{2},opt);
            end
            ndata=containers.Map(key,val);
            newdata{j}=ndata;
        end
        if(len==1)
            newdata=newdata{1};
        end
    end

    %% handle graph data
    if(isfield(data,N_('_GraphNodes_')) && exist('graph','file') && exist('digraph','file'))
        newdata=cell(len,1);
        isdirected=1;
        for j=1:len
            nodedata=data(j).(N_('_GraphNodes_'));
            if(isstruct(nodedata))
                nodetable=struct2table(nodedata);
            elseif(isa(nodedata,'containers.Map'))
                nodetable=[keys(nodedata);values(nodedata)];
                if(strcmp(nodedata.KeyType,'char'))
                    nodetable=table(nodetable(1,:)',nodetable(2,:)','VariableNames',{'Name','Data'});
                else
                    nodetable=table(nodetable(2,:)','VariableNames',{'Data'});
                end
            else
                nodetable=table;
            end

            if(isfield(data,N_('_GraphEdges_')))
                edgedata=data(j).(N_('_GraphEdges_'));
            elseif(isfield(data,N_('_GraphEdges0_')))
                edgedata=data(j).(N_('_GraphEdges0_'));
                isdirected=0;
            elseif(isfield(data,N_('_GraphMatrix_')))
                edgedata=jdatadecode(data(j).(N_('_GraphMatrix_')),varargin{:});
            end

            if(exist('edgedata','var'))
                if(iscell(edgedata))
                    endnodes=edgedata(:,1:2);
                    endnodes=reshape([endnodes{:}],size(edgedata,1),2);
                    weight=cell2mat(edgedata(:,3:end));
                    edgetable=table(endnodes,[weight.Weight]','VariableNames',{'EndNodes','Weight'});

                    if(isdirected)
                        newdata{j}=digraph(edgetable,nodetable);
                    else
                        newdata{j}=graph(edgetable,nodetable);
                    end
                elseif(ismatrix(edgedata) && isstruct(nodetable))
                    newdata{j}=digraph(edgedata,fieldnames(nodetable));
                end
            end
        end
        if(len==1)
            newdata=newdata{1};
        end
    end

    %% handle bytestream and arbitrary matlab objects
    if(isfield(data,N_('_ByteStream_')) && isfield(data,N_('_DataInfo_'))==2)
        newdata=cell(len,1);
        for j=1:len
            if(isfield(data(j).(N_('_DataInfo_')),'MATLABObjectClass'))
                if(needbase64)
                    newdata{j}=getArrayFromByteStream(base64decode(data(j).(N_('_ByteStream_'))));
                else
                    newdata{j}=getArrayFromByteStream(data(j).(N_('_ByteStream_')));
                end
            end
        end
        if(len==1)
            newdata=newdata{1};
        end
    end

    %% subfunctions 
    function escaped=N_(str)
      escaped=[prefix str];
    end
end