diff options
Diffstat (limited to 'eng/req/howto.rst')
| -rw-r--r-- | eng/req/howto.rst | 73 |
1 files changed, 42 insertions, 31 deletions
diff --git a/eng/req/howto.rst b/eng/req/howto.rst index 8481214..8d146a3 100644 --- a/eng/req/howto.rst +++ b/eng/req/howto.rst @@ -283,30 +283,41 @@ an :ref:`SpecTypeInterfaceForwardDeclarationItemType` item. Action Requirements ------------------- -Use :ref:`SpecTypeActionRequirementItemType` items to specify and validate -directive calls. Action requirements are a generator for event-driven -requirements which should be written in the following :ref:`syntax +:ref:`SpecTypeActionRequirementItemType` items may be used to specify and +validate directive calls. They are a generator for event-driven requirements. +Event-driven requirements should be written in the following :ref:`syntax <ReqEngSyntax>`: - *When* <optional preconditions> <trigger>, the <system name> shall - <system response>. - -The <optional preconditions> are the pre-conditions of the action requirement. -The <trigger> is the action of the action requirement. The post-conditions -should provide a list of the <system name> shall <system response> clauses. -Each transition in the transition map is an event-driven requirement composed -of the pre-condition states, the action, and the post-condition states defined -by the map entry. - -Use ``CamelCase`` for the pre-condition names, post-condition -names, and state names. The more conditions a directive has, the shorter -should be the names. The transition map may be documented as a table and more -conditions need more table columns. Use item attribute references in the -``text`` attributes. This allows context-sensitive substitutions. - -Link the action requirement item to an :ref:`SpecTypeInterfaceFunctionItemType` -or an :ref:`SpecTypeInterfaceMacroItemType` item using the -:ref:`SpecTypeInterfaceFunctionLinkRole`. + **While** <pre-condition 0>, **while** <pre-condition 1>, ..., **while** + <pre-condition *n*>, **when** <trigger>, the <system name> shall <system + response>. + +The list of *while* <pre-condition *i*> clauses for *i* from 1 to *n* in the +EARS notation is generated by *n* pre-condition states in the action +requirement item, see the ``pre-condition`` attribute in the +:ref:`SpecTypeActionRequirementItemType`. + +The <trigger> in the EARS notation is defined for an action requirement item by +the link to an :ref:`SpecTypeInterfaceFunctionItemType` or an +:ref:`SpecTypeInterfaceMacroItemType` item using the +:ref:`SpecTypeInterfaceFunctionLinkRole`. The code provided by the +``test-action`` attribute defines the action code which should invoke the +trigger directive in a particular set of pre-condition states. + +Each post-condition state of the action requirement item generates a <system +name> shall <system response> clause in the EARS notation, see the +``post-condition`` attribute in the :ref:`SpecTypeActionRequirementItemType`. + +Each entry in the transition map is an event-driven requirement composed of the +pre-condition states, the trigger defined by the link to a directive, and the +post-condition states. The transition map is defined by a list of +:ref:`SpecTypeActionRequirementTransition` descriptors. + +Use ``CamelCase`` for the pre-condition names, post-condition names, and state +names in action requirement items. The more conditions a directive has, the +shorter should be the names. The transition map may be documented as a table +and more conditions need more table columns. Use item attribute references in +the ``text`` attributes. This allows context-sensitive substitutions. Pre-Conditions ^^^^^^^^^^^^^^ @@ -322,20 +333,20 @@ syntax for directive object identifier parameters: test-code: | ctx->id = 0xffffffff; text: | - The ${../if/directive:/params[0]/name} parameter shall not be + While the ${../if/directive:/params[0]/name} parameter is not associated with a thing. - name: ClassA test-code: | ctx->id = ctx->class_a_id; text: | - The ${../if/directive:/params[0]/name} parameter shall be associated with a - class A thing. + While the ${../if/directive:/params[0]/name} parameter is associated + with a class A thing. - name: ClassB test-code: | ctx->id = ctx->class_b_id; text: | - The ${../if/directive:/params[0]/name} parameter shall be associated with a - class B thing. + While the ${../if/directive:/params[0]/name} parameter is associated + with a class B thing. test-epilogue: null test-prologue: null @@ -354,13 +365,13 @@ the following syntax for directive pointer parameters: test-code: | ctx->id = &ctx->id_value; text: | - The ${../if/directive:/params[3]/name} parameter shall reference an + While the ${../if/directive:/params[3]/name} parameter references an object of type ${../../type/if/id:/name}. - name: 'Null' test-code: | ctx->id = NULL; text: | - The ${../if/directive:/params[3]/name} parameter shall be + While the ${../if/directive:/params[3]/name} parameter is ${/c/if/null:/name}. test-epilogue: null test-prologue: null @@ -375,12 +386,12 @@ Use the following syntax for other directive parameters: test-code: | ctx->name = NAME; text: | - The ${../if/directive:/params[0]/name} parameter shall be valid. + While the ${../if/directive:/params[0]/name} parameter is valid. - name: Invalid test-code: | ctx->name = 0; text: | - The ${../if/directive:/params[0]/name} parameter shall be invalid. + While the ${../if/directive:/params[0]/name} parameter is invalid. test-epilogue: null test-prologue: null |