Filtering needs¶

Sphinx-Needs supports the filtering of need and need_parts by using easy to use options or powerful filter string.

Available options are specific to the used directive, whereas the filter string is supported by all directives and roles, which provide filter capabilities.

Filter options¶

The following filter options are supported by directives:

• needlist

• needtable

• needflow

• needpie

• needfilter (deprecated!)

• needextend

Related to the used directive and its representation, the filter options create a list of needs, which match the filters for status, tags, types and filter.

For :status:, :tags: and :types: values are separated by “;”. :filter: gets evaluated.

The logic, if a need belongs to the final result list, is as followed:

status = (open OR in_progress) AND tags = (user OR login) AND types = (req OR spec) AND eval(filter) is True

status¶

Use the status option to filter needs by their status.

You can easily filter for multiple statuses by separating them by “;”. Example: open; in progress; reopen.

.. needlist::
   :status: open
   :show_status:

tags¶

tags allows to filter needs by one or multiple tags.

To search for multiple tags, simply separate them by using “;”.

.. needlist::
   :tags: main_example
   :show_tags:

types¶

For :types: the type itself or the human-readable type-title can be used as filter value.

.. needtable::
   :types: test

sort_by¶

Sorts the result list. Allowed values are status or any alphanumerical property.

.. needtable::
   :sort_by: id
   :status: open

filter¶

The filter option allows the definition of a complex query string, which gets evaluated via eval() in Python. Please see Filter string for more details.

Filter string¶

The usage of a filter string is supported/required by:

• need_count

• needlist

• needtable

• needflow

• needpie

• needbar

The filter string must be a valid Python expression:

:need_count:`type=='spec' and status.upper()!='OPEN'`

A filter string gets evaluated on needs and need_parts! A need_part inherits all options from its parent need, if the need_part has no own content for this option. E.g. the need_part title is kept, but the status attribute is taken from its parent need.

This allows to perform searches for need_parts, where search options are based on parent attributes.

The following filter will find all need_parts, which are part of a need, which has a tag called important.

:need_count:`is_part and 'important' in tags`

Inside a filter string the following variables/functions can be used:

• tags as Python list (compare like "B" in tags)

• type as Python string (compare like "story" == type)

• status as Python string (compare like "opened" != status)

• sections as Python list with the hierarchy of sections with lowest-level section first. (compare like "Section Header" in sections)

• id as Python string (compare like "MY_ID_" in id)

• title as Python string (compare like len(title.split(" ")) > 5)

• links as Python list (compare like "ID_123" not in links)

• links_back as Python list (compare like "ID_123" not in links_back)

• content as Python string (compare like len(content) == 0)

• is_need as Python boolean. (compare like is_need)

• is_part as Python boolean. (compare like is_part)

• parts as Python list with need_part / np of the current need. (compare like len(parts)>0)

• search, as Python function for performing searches with a regular expression

• needs as Python dict. Contains all needs. Helpful to perform complex filters on links (added 0.3.15).

• sections as list of sections names, th which the need belongs to.

• section_name as string, which defines the last/lowest section a need belongs to.

• docname as string, which defines the name of the document in which a need is defined, without the extension (similar to Sphinx’ :doc: role)

• signature as string, which contains a function-name, possible set by sphinx-autodoc above the need.

• parent_need as string, which is an id of the need, which has the current need defined in its content (added 0.6.2).

• parent_needs as string, which is a list of need ids (added 0.6.2).

Additional variables for need_part / np:

• id_parent as Python string, which contains the id of the parent need. (compare like id_parent == "ABC_01")

• id_complete as Python string. Contains the concatenated ids of parent need and need_part. (compare like id_complete != 'ABC_01.03')

If your expression is valid and it’s True, the related need is added to the filter result list. If it is invalid or returns False, the related need is not taken into account for the current filter.

.. req:: Requirement A
   :tags: A; filter_example
   :status: open

.. req:: Requirement B
   :tags: B; filter_example
   :status: closed

.. spec:: Specification A
   :tags: A; filter_example
   :status: closed

.. spec:: Specification B
   :tags: B; filter_example
   :status: open

.. test:: Test 1
   :tags: filter_example

.. needtable::
   :filter: "filter_example" in tags and ("B" in tags or ("spec" == type and "closed" == status)) or "test" == type

search¶

search(pattern, variable) is based on Pythons re.search() function

The first parameter must be a regular expression pattern. The second parameter should be one of the above variables(status, id, content, ..)

Show example

This example uses a regular expressions to find all needs with an e-mail address in title.

.. req:: Set admin e-mail to admin@mycompany.com

.. needlist::
   :filter: search("([a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$)", title)

Requirement: Set admin e-mail to admin@mycompany.com R_17EB4

R_17EB4: Set admin e-mail to admin@mycompany.com

export_id¶

If set, the filter results get exported to needs.json, if the builder needs is used:

.. needtable::
   :status: open
   :filter: "test" in tags
   :export_id: filter_01

See Exporting filters for more details.

Filter code¶

The content of a needlist, needtable or needflow can be used to define own filters with the help of Python.

The used code must define a variable results, which must be a list and contains the filtered needs.

.. needtable::
   :columns: id, title, type, links, links_back
   :style: table

   # Collect all requirements and specs,
   # which are linked to each other.

   results = []
   # Lets create a needs_dict to address needs by ids more easily.
   needs_dict = {x['id']: x for x in needs}

   for need in needs:
      if need['type'] == 'req':
         for links_id in need['links']:
            if needs_dict[links_id]['type'] == 'spec':
               results.append(need)
               results.append(needs_dict[links_id])

The code has access to a variable called needs, which contains a copy of all needs. So manipulations on the values in needs do not have any affects.

This mechanism can also be a good alternative for complex filter strings to save performance. For example if a filter string is using list comprehensions to get access to linked needs.

If filter code is used, all other filter related options (like status or filters) are ignored.

Filter function¶

Nearly same behavior as Filter code, but the code gets read from an external python file and a function must be referenced.

option name:

filter-func

default:

None

Usage inside a rst file:

.. needtable:: Filter function example
   :filter-func: filter_file.own_filter_code

The code of the referenced file filter_file.py with function own_filter_code:

def own_filter_code(needs, results, **kwargs):
    for need in needs:
        if need["type"] == "test":
            results.append(need)

The function gets executed by Sphinx-Needs and it must provide two keyword arguments: needs and results.

Also the given package/module must be importable by the used Python environment. So it must be part of the Python Path variable. To update this, add sys.path.insert(0, os.path.abspath("folder/to/filter_files")) to your conf.py file.

Arguments¶

Filter function are supporting arguments: filter_file.own_filter_code(value_1,value_2).

Please note, that the part between (...) is just a comma separated list and each element will be given as string to the function.

The functions get the values as part of **kwargs with the name is arg<pos>, starting from 1.

Example:

.. needtable:: Filter function example
   :filter-func: filter_file.own_filter_code(1,2.5,open)

def own_filter_code(needs, results, **kwargs):
    for need in needs:
        if int(need["price"]) > int(kwargs["arg1"]) or need["status"] == kwargs["arg3"]:
            results.append(need)

The function developer is responsible to perform any needed typecast.

Needpie¶

needpie also supports filter-code. But instead of needs, a list of resulting numbers must be returned.

Example:

.. needpie:: Filter code func pie
   :labels: new,done
   :filter-func: filter_code_func.my_pie_filter_code_args(new,done)

def my_pie_filter_code_args(needs, results, **kwargs):
    cnt_x = 0
    cnt_y = 0
    for need in needs:
        if need["status"] == kwargs['arg1']:
            cnt_x += 1
        if need["status"] == kwargs['arg2']:
            cnt_y += 1

   results.append(cnt_x)
   results.append(cnt_y)

Filter matches nothing¶

Depending on the directive used a filter that matches no needs may add text to inform that no needs are found.

The default text “No needs passed the filter”.

If this is not intended, add the option

filter_warning¶

Add specific text with this option or add no text to display nothing. The default text will not be shown.

The specified output could be styled with the css class needs_filter_warning