diff --git a/README.md b/README.md
index b7ba485c8a1992adc466b3d6b4a9bcb305a88f6e..634704408984f0e218d49fa811d01ea3b7935070 100644
--- a/README.md
+++ b/README.md
@@ -147,6 +147,72 @@ Example:
'BEA/NIUnderlyingDetail-U001BC/S315-Q',...
'BEA/NIUnderlyingDetail-U001BC/S315-M'});
+### Fetch the available datasets of a provider
+When fetching series from DBnomics, the user needs to give a provider and a dataset before specifying correct dimensions.
+With the function `mdbnomics_datasets`, the user can download the list of the available datasets for a provider.
+If no `provider_code` was supplied, an array of all datasets for every provider is returned.
+
+Example:
+
+ >> datasets = mdbnomics_datasets('provider_code', 'IMF');
+
+The result is a structure with with a cell array containing the dataset codes and names of the requested providers.
+With the same function, if the user wants to fetch the available datasets for multiple providers, a cell array of providers has to be given.
+
+Example:
+
+ >> datasets = mdbnomics_datasets('provider_code', {'IMF', 'BDF'});
+
+In the event that the user only requests the datasets for one provider, if `simplify` is defined as `true`, then the result will be a simple cell array, not a structure.
+
+Example:
+
+ >> datasets = mdbnomics_datasets('provider_code', 'IMF', 'simplify', true);
+
+### Fetch the possible dimensions of available datasets of a provider
+When fetching series from DBnomics, it can be interesting and especially useful to specify dimensions for a particular dataset to download only the series you want to analyse. With the function `mdbnomics_dimensions`,
+the user can download these dimensions and their meanings.
+
+Example:
+
+ >> datasets = mdbnomics_dimensions('provider_code', 'IMF', 'dataset_code', 'WEO');
+
+The result is a nested structure (its names are IMF_WEO and the dimensions names) with a structure at the end of each branch.
+
+In the event that the user only requests the dimensions for one dataset for one provider, if `simplify` is defined as `true`, then the result will be a simple structure, not a nested one.
+
+Example:
+
+ >> datasets = mdbnomics_dimensions('provider_code', 'IMF', 'dataset_code', 'WEO', 'simplify', true);
+
+To download the dimensions of every dataset gathered by DBnomics, the user does not have to set any arguments.
+
+Example:
+
+ >> datasets = mdbnomics_dimensions();
+
+### Fetch the series codes and names of available datasets of a provider
+The user can download the list of series, and especially their codes, of a dataset’s provider by using the function `mdbnomics_series`. The result is a structure with a cell array at the end of each branch. If `simplify` is defined as `true`,
+then the result will be a simple cell array.
+
+Example:
+
+ >> series = mdbnomics_series('provider_code', 'IMF', 'dataset_code', 'WEO', 'simplify', true);
+
+Like the function `mdbnomics()`, features can be added to `mdbnomics_series()`. The user can ask for the series with specific dimensions:
+
+Example:
+
+ >> series = mdbnomics_series('provider_code', 'IMF', 'dataset_code', 'WEO', 'dimensions', '{"weo-subject":["NGDP_RPCH"]}', 'simplify', true);
+
+or with a query:
+
+Example:
+
+ >> series = mdbnomics_series('provider_code', 'IMF', 'dataset_code', 'WEO', 'query', 'NGDP_RPCH');
+
+> :warning: **We ask the user to use this function parsimoniously because there are a huge amount of series per dataset. Please only fetch for one dataset if you need it or visit the DBnomics website.**
+
### Transform time series
The routines can interact with the [Time Series Editor](https://editor.nomics.world/) to transform time series by applying filters to them.
Available filters are listed on the [filters page](https://editor.nomics.world/filters).
diff --git a/src/mdbnomics_datasets.m b/src/mdbnomics_datasets.m
new file mode 100644
index 0000000000000000000000000000000000000000..2bfa5962d679551a2a28abf8acd64c44817a66bf
--- /dev/null
+++ b/src/mdbnomics_datasets.m
@@ -0,0 +1,137 @@
+function datasets = mdbnomics_datasets(varargin) % --*-- Unitary tests --*--
+% function mdbnomics_datasets(varargin)
+% Downloads the list of available datasets for a selection of providers (or all of them) from https://db.nomics.world/.
+% By default, the function returns a structure with a cell array containing the dataset codes and names of the requested providers.
+%
+% POSSIBLE PARAMETERS
+% provider_code [char] DBnomics code of one or multiple providers. If empty, the providers are firstly
+% dowloaded with the function mdbnomics_providers and then the available datasets are requested.
+% simplify [logical] If true, when the datasets are requested for only one provider then a cell array is returned, not a structure.
+% If not provided, the default value is false.
+%
+% OUTPUTS
+% datasets
+%
+% SPECIAL REQUIREMENTS
+% none
+
+% Copyright (C) 2020 Dynare Team
+%
+% This file is part of Dynare.
+%
+% Dynare 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 3 of the License, or
+% (at your option) any later version.
+%
+% Dynare 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 Dynare. If not, see <http://www.gnu.org/licenses/>.
+
+api_base_url = 'https://api.db.nomics.world';
+api_version = 22;
+
+p = inputParser;
+validStringInput = @(x) ischar(x) || iscellstr(x);
+p.addParameter('provider_code', '', validStringInput);
+p.addParameter('simplify', false, @islogical);
+p.KeepUnmatched = false;
+p.parse(varargin{:});
+
+if isempty(p.Results.provider_code)
+ provider_code = mdbnomics_providers('code', true);
+else
+ if ischar(p.Results.provider_code)
+ provider_code = {p.Results.provider_code};
+ else
+ provider_code = p.Results.provider_code;
+ end
+end
+
+datasets = struct();
+for i = 1:numel(provider_code)
+ pc = provider_code{i};
+ provider_page = sprintf('%s/v%d/providers/%s', api_base_url, api_version, pc);
+ provider_info = webread(provider_page);
+ provider_info = provider_info.category_tree;
+ code = [];
+ name = [];
+ if isfield(provider_info, 'children')
+ unpack_children(provider_info, code, name);
+ else
+ try
+ for n = 1:numel(provider_info)
+ code = [code, {provider_info{n}.code}];
+ name = [name, {provider_info{n}.name}];
+ end
+ catch
+ for n = 1:numel(provider_info)
+ code = [code, {provider_info(n).code}];
+ name = [name, {provider_info(n).name}];
+ end
+ end
+ end
+ datasets.(pc) = horzcat(code', name');
+end
+
+if p.Results.simplify
+ if length(fieldnames(datasets)) == 1
+ datasets = datasets.(pc);
+ else
+ error('Your query corresponds to multiple providers, not possible to simplify');
+ end
+end
+end
+
+%@test:1
+%$ try
+%$ datasets = mdbnomics_datasets('provider_code', 'IMF', 'simplify', true);
+%$ t(1) = 1;
+%$ catch
+%$ t = 0;
+%$ end
+%$
+%$ if t(1)
+%$ t(2) = dassert(length(unique(datasets(:,1))), 43);
+%$ t(3) = dassert(size(datasets, 2), 2);
+%$ end
+%$
+%$ T = all(t);
+%@eof:1
+
+%@test:2
+%$ try
+%$ datasets = mdbnomics_datasets('provider_code', 'IMF');
+%$ t(1) = 1;
+%$ catch
+%$ t = 0;
+%$ end
+%$
+%$ if t(1)
+%$ t(2) = dassert(fieldnames(datasets), {'IMF'});
+%$ t(3) = dassert(size(datasets.IMF,1), 43);
+%$ end
+%$
+%$ T = all(t);
+%@eof:2
+
+%@test:3
+%$ try
+%$ datasets = mdbnomics_datasets('provider_code', {'IMF', 'AMECO'});
+%$ t(1) = 1;
+%$ catch
+%$ t = 0;
+%$ end
+%$
+%$ if t(1)
+%$ t(2) = dassert(fieldnames(datasets), {'IMF'; 'AMECO'});
+%$ t(3) = dassert(size(datasets.IMF,1), 43);
+%$ t(4) = dassert(size(datasets.AMECO,1), 473);
+%$ end
+%$
+%$ T = all(t);
+%@eof:3
\ No newline at end of file
diff --git a/src/mdbnomics_dimensions.m b/src/mdbnomics_dimensions.m
new file mode 100644
index 0000000000000000000000000000000000000000..0196ae23155ba397699747a958f1a8a00696cb06
--- /dev/null
+++ b/src/mdbnomics_dimensions.m
@@ -0,0 +1,153 @@
+function dimensions = mdbnomics_dimensions(varargin) % --*-- Unitary tests --*--
+% function mdbnomics_dimensions(varargin)
+% Downloads the list of dimensions (if they exist) for available datasets of a selection of providers from https://db.nomics.world/.
+% By default, the function returns a structure containing the dimensions of datasets for DBnomics providers.
+%
+% POSSIBLE PARAMETERS
+% provider_code [char] DBnomics code of one or multiple providers. If empty, the providers are firstly
+% dowloaded with the function mdbnomics_providers and then the available datasets are requested.
+% dataset_code [char] DBnomics code of one or multiple datasets of a provider. If empty, the datasets codes are dowloaded
+% with the function mdbnomics_datasets and then the dimensions are requested.
+% simplify [logical] If true, when the dimensions are requested for only one provider and one dataset then only the dimension names and their values are provided.
+% If not provided, the default value is false.
+%
+% OUTPUTS
+% dimensions
+%
+% SPECIAL REQUIREMENTS
+% none
+
+% Copyright (C) 2020 Dynare Team
+%
+% This file is part of Dynare.
+%
+% Dynare 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 3 of the License, or
+% (at your option) any later version.
+%
+% Dynare 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 Dynare. If not, see <http://www.gnu.org/licenses/>.
+
+api_base_url = 'https://api.db.nomics.world';
+api_version = 22;
+
+p = inputParser;
+validStringInput = @(x) ischar(x) || iscellstr(x);
+p.addParameter('provider_code', '', validStringInput);
+p.addParameter('dataset_code', '', validStringInput);
+p.addParameter('simplify', false, @islogical);
+p.KeepUnmatched = false;
+p.parse(varargin{:});
+
+if isempty(p.Results.provider_code) && ~isempty(p.Results.dataset_code)
+ error('When you use dataset_code, you must specify provider_code as well.');
+end
+
+if iscell(p.Results.provider_code) || iscell(p.Results.dataset_code)
+ if ~isempty(p.Results.provider_code) && ~isempty(p.Results.dataset_code) && length(p.Results.provider_code) ~= length(p.Results.dataset_code)
+ error('Please specify as many provider codes as dataset codes.')
+ end
+end
+
+if isempty(p.Results.provider_code)
+ provider_code = mdbnomics_providers('code', true);
+else
+ if ischar(p.Results.provider_code)
+ provider_code = {p.Results.provider_code};
+ else
+ provider_code = p.Results.provider_code;
+ end
+end
+
+if isempty(p.Results.dataset_code)
+ dataset_code = mdbnomics_datasets('provider_code', provider_code);
+else
+ if ischar(p.Results.dataset_code)
+ dataset_code = {p.Results.dataset_code};
+ else
+ dataset_code = p.Results.dataset_code;
+ end
+end
+
+dimensions = struct();
+for i = 1:numel(provider_code)
+ pc = provider_code{i};
+ dc = dataset_code{i};
+ dataset_page = sprintf('%s/v%d/datasets/%s/%s', api_base_url, api_version, pc, dc);
+ dataset_info = webread(dataset_page);
+ dataset_name = sprintf('%s_%s', pc, dc);
+
+ try
+ tmp1 = dataset_info.datasets.docs.dimensions_labels;
+ catch
+ try
+ tmp1 = dataset_info.datasets.(dataset_name).dimensions_labels;
+ catch
+ tmp1 = {};
+ end
+ end
+
+ try
+ tmp2 = dataset_info.datasets.docs.dimensions_values_labels;
+ catch
+ try
+ tmp2 = dataset_info.datasets.(dataset_name).dimensions_values_labels;
+ catch
+ tmp2 = {};
+ end
+ end
+
+ dataset_dimensions = fieldnames(tmp1);
+ for d = 1:numel(dataset_dimensions)
+ dimensions.(dataset_name).(dataset_dimensions{d}) = tmp2.(dataset_dimensions{d});
+ end
+end
+
+if p.Results.simplify
+ if length(fieldnames(dimensions)) == 1
+ dimensions = dimensions.(dataset_name);
+ else
+ error('Your query corresponds to multiple datasets, not possible to simplify');
+ end
+end
+end
+
+%@test:1
+%$ try
+%$ dimensions = mdbnomics_dimensions('provider_code', 'IMF', 'dataset_code', 'WEO');
+%$ t(1) = 1;
+%$ catch
+%$ t = 0;
+%$ end
+%$
+%$ if t(1)
+%$ t(2) = dassert(fieldnames(dimensions), {'IMF_WEO'});
+%$ t(3) = dassert(isfield(dimensions.IMF_WEO, 'unit'), true);
+%$ t(4) = dassert(length(fieldnames(dimensions.IMF_WEO.unit)), 13);
+%$ end
+%$
+%$ T = all(t);
+%@eof:1
+
+%@test:2
+%$ try
+%$ dimensions = mdbnomics_dimensions('provider_code', 'IMF', 'dataset_code', 'WEO', 'simplify', true);
+%$ t(1) = 1;
+%$ catch
+%$ t = 0;
+%$ end
+%$
+%$ if t(1)
+%$ t(2) = dassert(isfield(dimensions, 'IMF_WEO'), false);
+%$ t(3) = dassert(isfield(dimensions, 'unit'), true);
+%$ t(4) = dassert(length(fieldnames(dimensions.unit)), 13);
+%$ end
+%$
+%$ T = all(t);
+%@eof:2
diff --git a/src/mdbnomics_series.m b/src/mdbnomics_series.m
new file mode 100644
index 0000000000000000000000000000000000000000..f76ec977e9e7bb5fcee098875ffdf95032382ffb
--- /dev/null
+++ b/src/mdbnomics_series.m
@@ -0,0 +1,238 @@
+function series = mdbnomics_series(varargin) % --*-- Unitary tests --*--
+% function mdbnomics_series(varargin)
+% Downloads the list of series for available datasets of a selection of providers from https://db.nomics.world/.
+% We warn the user that this function can be (very) long to execute!
+% We remind that DBnomics requests data from 63 providers to retrieve 21675 datasets for a total of approximately 720 millions series.
+% By default, the function returns a structure with a cell array at the end of each branch containing the series codes and names of datasets for DBnomics providers.
+%
+% POSSIBLE PARAMETERS
+% provider_code [char] DBnomics code of one or multiple providers. If empty, the providers are firstly
+% dowloaded with the function mdbnomics_providers and then the available datasets are requested.
+% dataset_code [char] DBnomics code of one or multiple datasets of a provider. If empty, the datasets codes are dowloaded
+% with the function mdbnomics_datasets and then the dimensions are requested.
+% dimensions [char] DBnomics code of one or several dimensions in the specified provider and dataset.
+% If provided it must be a string formatted like: '{"country":["ES","FR","IT"],"indicator":["IC.REG.COST.PC.FE.ZS.DRFN"]}'.
+% query [char] A query to filter/select series from a provider's dataset.
+% only_number_of_series [logical] If true, only the number of series for the given query will be printed in the command window.
+% If not provided, the default value is false.
+% simplify [logical] If true, when the datasets are requested for only one provider then a cell array is returned, not a structure.
+% If not provided, the default value is false.
+%
+% OUTPUTS
+% series
+%
+% SPECIAL REQUIREMENTS
+% none
+
+% Copyright (C) 2020 Dynare Team
+%
+% This file is part of Dynare.
+%
+% Dynare 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 3 of the License, or
+% (at your option) any later version.
+%
+% Dynare 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 Dynare. If not, see <http://www.gnu.org/licenses/>.
+
+api_base_url = 'https://api.db.nomics.world';
+api_version = 22;
+
+p = inputParser;
+validStringInput = @(x) ischar(x) || iscellstr(x);
+p.addParameter('provider_code', '', validStringInput);
+p.addParameter('dataset_code', '', validStringInput);
+p.addParameter('dimensions', '', validStringInput);
+p.addParameter('query', '', validStringInput);
+p.addParameter('only_number_of_series', false, @islogical);
+p.addParameter('simplify', false, @islogical);
+p.KeepUnmatched = false;
+p.parse(varargin{:});
+
+if iscell(p.Results.provider_code) || iscell(p.Results.dataset_code)
+ if ~isempty(p.Results.provider_code) && ~isempty(p.Results.dataset_code) && length(p.Results.provider_code) ~= length(p.Results.dataset_code)
+ error('Please specify as many provider codes as dataset codes.')
+ end
+end
+
+if isempty(p.Results.provider_code)
+ provider_code = mdbnomics_providers('code', true);
+else
+ if ischar(p.Results.provider_code)
+ provider_code = {p.Results.provider_code};
+ else
+ provider_code = p.Results.provider_code;
+ end
+end
+
+if isempty(p.Results.dataset_code)
+ dataset_code = mdbnomics_datasets('provider_code', provider_code);
+else
+ if ischar(p.Results.dataset_code)
+ dataset_code = {p.Results.dataset_code};
+ else
+ dataset_code = p.Results.dataset_code;
+ end
+end
+
+if ~isempty(p.Results.query)
+ if ischar(p.Results.query)
+ db_query = {p.Results.query};
+ else
+ db_query = p.Results.query;
+ end
+end
+
+if ~isempty(p.Results.dimensions)
+ if ischar(p.Results.dimensions)
+ dimensions = {p.Results.dimensions};
+ else
+ dimensions = p.Results.dimensions;
+ end
+end
+
+series = struct();
+for i = 1:numel(provider_code)
+ pc = provider_code{i};
+ dc = dataset_code{i};
+ dataset_page = sprintf('%s/v%d/series/%s/%s', api_base_url, api_version, pc, dc);
+ if exist('db_query', 'var')
+ dataset_page = sprintf('%s?q=%s', dataset_page, db_query{i});
+ end
+
+ if exist('dimensions', 'var')
+ if contains(dimensions{i}, '\\?')
+ spec = '&';
+ else
+ spec = '?';
+ end
+ dataset_page = sprintf('%s%sdimensions=%s', dataset_page, spec, dimensions{i});
+ end
+
+ dataset_info = webread(dataset_page);
+ dataset_name = sprintf('%s_%s', pc, dc);
+ limit = dataset_info.series.limit;
+ num_found = dataset_info.series.num_found;
+
+ if p.Results.only_number_of_series
+ sprintf('Number of series = %d', num_found)
+ return
+ else
+ sprintf('The dataset %s from provider %s contains %d series.', dc, pc, num_found)
+ series_code = [];
+ series_name = [];
+
+ if num_found > limit
+ sequence = 0:1:floor(num_found/limit);
+
+ if contains(dataset_page, 'offset=')
+ dataset_page = regexprep(dataset_page, '\\&offset=[0-9]+', '');
+ dataset_page = regexprep(dataset_page, '\\?offset=[0-9]+', '');
+ end
+
+ if contains(dataset_page, '\\?')
+ sep = '&';
+ else
+ sep = '?';
+ end
+
+ for j = 1:numel(sequence)
+ tmp_api_link = sprintf('%s%soffset=%d', dataset_page, sep, sequence(j)*limit);
+ dataset_info = webread(tmp_api_link);
+ series_info = dataset_info.series.docs;
+ for s = 1:numel(series_info)
+ series_code = [series_code, {series_info(s).series_code}];
+ series_name = [series_name, {series_info(s).series_name}];
+ end
+ end
+ series.(dataset_name) = horzcat(series_code', series_name');
+ else
+ series_info = dataset_info.series.docs;
+ for s = 1:numel(series_info)
+ series_code = [series_code, {series_info(s).series_code}];
+ series_name = [series_name, {series_info(s).series_name}];
+ end
+ series.(dataset_name) = horzcat(series_code', series_name');
+ end
+ end
+end
+
+if p.Results.simplify
+ if length(fieldnames(series)) == 1
+ series = series.(dataset_name);
+ else
+ error('Your query corresponds to multiple datasets, not possible to simplify');
+ end
+end
+end
+
+%@test:1
+%$ try
+%$ series = mdbnomics_series('provider_code', 'IMF', 'dataset_code', 'WEO', 'simplify', true);
+%$ t(1) = 1;
+%$ catch
+%$ t = 0;
+%$ end
+%$
+%$ if t(1)
+%$ t(2) = dassert(length(unique(series(:,1))), 8924);
+%$ t(3) = dassert(size(series, 2), 2);
+%$ end
+%$
+%$ T = all(t);
+%@eof:1
+
+%@test:2
+%$ try
+%$ series = mdbnomics_series('provider_code', 'IMF', 'dataset_code', 'WEO');
+%$ t(1) = 1;
+%$ catch
+%$ t = 0;
+%$ end
+%$
+%$ if t(1)
+%$ t(2) = dassert(fieldnames(series), {'IMF_WEO'});
+%$ t(3) = dassert(length(unique(series.IMF_WEO(:,1))), 8924);
+%$ t(4) = dassert(size(series.IMF_WEO, 2), 2);
+%$ end
+%$
+%$ T = all(t);
+%@eof:2
+
+%@test:3
+%$ try
+%$ series = mdbnomics_series('provider_code', 'IMF', 'dataset_code', 'WEO', 'dimensions', '{"weo-subject":["NGDP_RPCH"]}', 'simplify', true);
+%$ t(1) = 1;
+%$ catch
+%$ t = 0;
+%$ end
+%$
+%$ if t(1)
+%$ t(2) = dassert(length(unique(series(:,1))), 194);
+%$ t(3) = dassert(size(series, 2), 2);
+%$ end
+%$
+%$ T = all(t);
+%@eof:3
+
+%@test:4
+%$ try
+%$ series = mdbnomics_series('provider_code', 'IMF', 'dataset_code', 'WEO', 'query', 'NGDP_RPCH');
+%$ t(1) = 1;
+%$ catch
+%$ t = 0;
+%$ end
+%$
+%$ if t(1)
+%$ t(2) = dassert(length(unique(series.IMF_WEO(:,1))), 194);
+%$ t(3) = dassert(size(series.IMF_WEO, 2), 2);
+%$ end
+%$
+%$ T = all(t);
+%@eof:4
\ No newline at end of file
diff --git a/src/utils/mdbnomics_providers.m b/src/utils/mdbnomics_providers.m
new file mode 100644
index 0000000000000000000000000000000000000000..35fd36148f039fd6adbc1fed9c4cfd41b8496881
--- /dev/null
+++ b/src/utils/mdbnomics_providers.m
@@ -0,0 +1,106 @@
+function providers = mdbnomics_providers(varargin) % --*-- Unitary tests --*--
+% function mdbnomics_providers(varargin)
+% Downloads the list of DBnomics providers from https://db.nomics.world/.
+% By default, the function returns a cell array containing the list of providers
+% with additional informations such as the region, the website, etc.
+%
+% POSSIBLE PARAMETERS
+% code [logical] If true, then only the providers are returned in a vector. If not provided, the default value is false.
+%
+% OUTPUTS
+% providers
+%
+% SPECIAL REQUIREMENTS
+% none
+
+% Copyright (C) 2020 Dynare Team
+%
+% This file is part of Dynare.
+%
+% Dynare 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 3 of the License, or
+% (at your option) any later version.
+%
+% Dynare 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 Dynare. If not, see <http://www.gnu.org/licenses/>.
+
+api_base_url = 'https://api.db.nomics.world';
+api_version = 22;
+
+p = inputParser;
+p.addParameter('code', false, @islogical);
+p.KeepUnmatched = false;
+p.parse(varargin{:});
+
+providers_url = sprintf('%s/v%d/providers', api_base_url, api_version);
+response = webread(providers_url);
+
+if p.Results.code
+ providers = cell(size(response.providers.docs, 1),1);
+ for i = 1:size(response.providers.docs, 1)
+ providers{i} = response.providers.docs{i}.code;
+ end
+ providers(cellfun('isempty',providers)) = [];
+else
+ providers = response.providers.docs;
+end
+end
+
+%@test:1
+%$ try
+%$ providers = mdbnomics_providers('code', true);
+%$ t(1) = 1;
+%$ catch
+%$ t = 0;
+%$ end
+%$
+%$ if t(1)
+%$ t(2) = dassert(length(unique(providers)), 67);
+%$ t(3) = dassert(providers{1}, 'AFDB');
+%$ t(4) = dassert(providers{67}, 'WTO');
+%$ end
+%$
+%$ T = all(t);
+%@eof:1
+
+%@test:2
+%$ try
+%$ providers = mdbnomics_providers('code', false);
+%$ t(1) = 1;
+%$ catch
+%$ t = 0;
+%$ end
+%$
+%$ if t(1)
+%$ t(2) = dassert(isstruct(providers{1}), true);
+%$ t(3) = dassert(size(providers,1), 67);
+%$ t(4) = dassert(providers{1}.code, 'AFDB');
+%$ t(5) = dassert(providers{67}.code, 'WTO');
+%$ end
+%$
+%$ T = all(t);
+%@eof:2
+
+%@test:3
+%$ try
+%$ providers = mdbnomics_providers();
+%$ t(1) = 1;
+%$ catch
+%$ t = 0;
+%$ end
+%$
+%$ if t(1)
+%$ t(2) = dassert(isstruct(providers{1}), true);
+%$ t(3) = dassert(size(providers,1), 67);
+%$ t(4) = dassert(providers{1}.code, 'AFDB');
+%$ t(5) = dassert(providers{67}.code, 'WTO');
+%$ end
+%$
+%$ T = all(t);
+%@eof:3
diff --git a/src/utils/unpack_children.m b/src/utils/unpack_children.m
new file mode 100644
index 0000000000000000000000000000000000000000..fbf35db524ca2890b45ae16d64589ddbd76cf722
--- /dev/null
+++ b/src/utils/unpack_children.m
@@ -0,0 +1,51 @@
+function unpack_children(structure, code, name)
+% function unpack_children(structure, code, name)
+% Recursively unpacks nested strcuture with fieldname 'children'.
+% Returns arrays of dataset codes and names to the caller workspace.
+%
+% INPUTS
+% structure [struct] structure to be unpacked
+% code [array] array of dataset codes
+% name [array] array of dataset names
+%
+% OUTPUTS
+% code, name in caller workspace
+%
+% SPECIAL REQUIREMENTS
+% none
+
+% Copyright (C) 2020 Dynare Team
+%
+% This file is part of Dynare.
+%
+% Dynare 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 3 of the License, or
+% (at your option) any later version.
+%
+% Dynare 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 Dynare. If not, see <http://www.gnu.org/licenses/>.
+
+for i = 1:numel(structure)
+ if isfield(structure(i), 'children')
+ child = structure(i).children;
+ if isstruct(child)
+ unpack_children(child, code, name)
+ continue;
+ end
+ else
+ code = [code, {structure(i).code}];
+ name = [name, {structure(i).name}];
+ end
+end
+
+assignin('caller', 'code', code);
+assignin('caller', 'name', name);
+end
+
+