Re: [pgAdmin4][Patch]: Dependecies/Dependents functionality - Mailing list pgadmin-hackers

On Fri, Feb 19, 2016 at 1:09 PM, Akshay Joshi <akshay.joshi@enterprisedb.com> wrote:

Hi Dave

On Fri, Feb 19, 2016 at 5:45 PM, Dave Page <dpage@pgadmin.org> wrote:

Hi

On Fri, Feb 19, 2016 at 10:17 AM, Akshay Joshi <akshay.joshi@enterprisedb.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.

 

  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

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Akshay Joshi

Principal Software Engineer 

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

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Dave Page
Blog: http://pgsnake.blogspot.com
Twitter: @pgsnake

EnterpriseDB UK: http://www.enterprisedb.com
The Enterprise PostgreSQL Company