Re: [pgAdmin4][Patch]: Dependecies/Dependents functionality

Hi All

I have modified the logic as per suggested by Dave. In new implementation I
have added two methods "get_dependencies" and "get_dependents" to the
class "PGChildNodeView". As per Ashesh's last commit all the
view(respective node's view) classes is derived from "PGChildNodeView"
instead of "NodeView", the above two methods will be directly accessible in
the respective node's view class. If there is a change in the functionality
to fetch dependencies/dependents for any node, developer of that node can
easily overload the function and provide their own logic. Following are the
changes need to be done to add this feature

*Add following lines of code in** <your module>.js*

- Add *hasDepends: true *in your file just like we have added *hasSQL*.

*Add following lines of code in <your module>.__init__.py*

Derive your view class from "PGChildNodeView" instead of "NodeView".

Implement the dependents and dependencies function like below. Pass the
appropriate node id to the functions "get_dependents" and
"get_dependencies".

@check_precondition
def dependents(self, gid, sid, did, lid):
"""
This function get the dependents and return ajax response
for the language node.

Args:
gid: Server Group ID
sid: Server ID
did: Database ID
lid: Language ID
"""
dependents_result = self.get_dependents(self.conn, lid)
return ajax_response(
response=dependents_result,
status=200
)

@check_precondition
def dependencies(self, gid, sid, did, lid):
"""
This function get the dependencies and return ajax response
for the language node.

Args:
gid: Server Group ID
sid: Server ID
did: Database ID
lid: Language ID
"""
dependencies_result = self.get_dependencies(self.conn, lid)
return ajax_response(
response=dependencies_result,
status=200
)

On Fri, Feb 19, 2016 at 6:51 PM, Akshay Joshi <akshay(dot)joshi(at)enterprisedb(dot)com
> wrote:

>
>
> On Fri, Feb 19, 2016 at 6:45 PM, Dave Page <dpage(at)pgadmin(dot)org> wrote:
>
>>
>>
>> On Fri, Feb 19, 2016 at 1:09 PM, Akshay Joshi <
>> akshay(dot)joshi(at)enterprisedb(dot)com> wrote:
>>
>>> Hi Dave
>>>
>>> On Fri, Feb 19, 2016 at 5:45 PM, Dave Page <dpage(at)pgadmin(dot)org> wrote:
>>>
>>>> Hi
>>>>
>>>> On Fri, Feb 19, 2016 at 10:17 AM, Akshay Joshi <
>>>> akshay(dot)joshi(at)enterprisedb(dot)com> wrote:
>>>>
>>>>> Hi All
>>>>>
>>>>> I have implemented the logic to show Dependencies/Dependents when user
>>>>> click on browser nodes. Attached is the patch file, please review it and if
>>>>> it looks good then please commit it.
>>>>>
>>>>> I have also added this support in "Database" , "Tablespace" and
>>>>> "Role" as this nodes are already been committed. Following is the
>>>>> information about how to add the support in other nodes
>>>>>
>>>>
>>>> It seems to me that this patch is implemented in a way to violates
>>>> modularity - specifically, it adds smarts about a child node into the code
>>>> for a parent node, rather than leaving each node to be self-contained. For
>>>> example, web/pgadmin/browser/server_groups/servers/depends.py contains the
>>>> SQL and other logic for displaying the dependencies and dependents of
>>>> tablespace and role nodes.
>>>>
>>>> I would expect to see role-specific code confined to the roles module,
>>>> database-specific confined to the database module and so on.
>>>>
>>>
>>> If I understand you correctly, you want me to remove logic to fetch
>>> dependencies/dependent for the "Tablespace" and "Role" node from the
>>> web/pgadmin/browser/server_groups/servers/depends.py and added it into
>>> the respective nodes? Logic to fetch Dependents is different for "
>>> Tablespace" and "Role", but to fetch Dependencies logic is generic for
>>> all the nodes( for sequence node we have one extra query). Similarly to
>>> fetch dependents we will have one extra query for Table and Column Node, so
>>> you want me to remove that part as well? in that case it's responsibility
>>> of the developer who will implement the Table/Column/Sequence node to add
>>> that logic later?
>>>
>>
>> Yes. Each node should be self-contained, and not include any non-generic
>> code relating to other nodes.
>>
>
> OK. Will do that
>
>>
>>
>
>>
>>>
>>> I have followed the pgAdmin3 code here, and also thought that it's
>>> better to have whole logic to fetch Dependencies/Dependent in a single
>>> file, instead of having some code (generic logic) in one file(depends.py)
>>> and some part in respective modules __init__.py.
>>>
>>
>> Well you can still have only a single copy of any generic code - put it
>> in a base class and have nodes inherit that.
>>
>> We're trying to fix (and change, by making things modular) some of the
>> design choices in pgAdmin 3, so it's not necessarily a good idea to copy
>> code structure from there.
>>
>>
>>>
>>>> As a side-note - shouldn't the code also use SQL templates for the SQL,
>>>> rather than hard-coding it into Python? I would expect to see it using the
>>>> same versioning mechanism we use elsewhere, to make it a simple matter of
>>>> adding a new template to update to support a new version of Postgres.
>>>>
>>>
>>> Sure, I'll do that.
>>>
>>
>> Thanks.
>>
>>
>>>
>>>> Thanks.
>>>>
>>>> --
>>>> Dave Page
>>>> Blog: http://pgsnake.blogspot.com
>>>> Twitter: @pgsnake
>>>>
>>>> EnterpriseDB UK: http://www.enterprisedb.com
>>>> The Enterprise PostgreSQL Company
>>>>
>>>
>>>
>>>
>>> --
>>> *Akshay Joshi*
>>> *Principal Software Engineer *
>>>
>>>
>>>
>>> *Phone: +91 20-3058-9517 <%2B91%2020-3058-9517>Mobile: +91 976-788-8246*
>>>
>>
>>
>>
>> --
>> Dave Page
>> Blog: http://pgsnake.blogspot.com
>> Twitter: @pgsnake
>>
>> EnterpriseDB UK: http://www.enterprisedb.com
>> The Enterprise PostgreSQL Company
>>
>
>
>
> --
> *Akshay Joshi*
> *Principal Software Engineer *
>
>
>
> *Phone: +91 20-3058-9517Mobile: +91 976-788-8246*
>

--
*Akshay Joshi*
*Principal Software Engineer *

*Phone: +91 20-3058-9517Mobile: +91 976-788-8246*