"sub-outcode" method

[billinghamj]

I've just started integrating a new data set into one of our systems, and sigh the postcode mappings use a funky version of standard outcodes.

For most cases, the full outcode is correct. e.g.:

• AB1 1AB -> AB1
• AA11 1AA -> AA11

But for the few London outcodes which end with letters, the letter is excluded. e.g.:

• EC1V 1AA -> EC1
• AA1A 1AA -> AA1

This seems like something useful to support in postcode.js. The only issue is I'm not sure what this would be called. It's not documented anywhere from what I can tell.

Any opinions/ideas naming-wise? I'll submit a PR once a name is figured out.

Thanks!

[cblanc]

That's an interesting use case.

I'm struggling to come up with an a simple name that encapsulates what it does. subOutcode is better than all the ones I can think of

I suppose as long as the method is well documented in the readme it won't be the end of the world if the perfect name can't be found

[stephenkeable]

Pretty sure it's known as a "sub district"

Stephen Keable
www.stephenkeable.co.uk

On 27 Aug 2015, at 18:23, Chris Blanchard notifications@github.com wrote:

That's an interesting use case.

I'm struggling to come up with an a simple name that encapsulates what it does. subOutcode is better than all the ones I can think of

I suppose as long as the method is well documented in the readme it won't be the end of the world if a suitable name isn't found

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[billinghamj]

Wikipedia article seems to agree:

https://en.m.wikipedia.org/wiki/London_postal_district#Numbered_divisions

I'll define two new methods:

• district - alias of outcode
• subDistrict - district without number

Sent from my iPhone

On 27 Aug 2015, 20:08 +0100, Stephen Keablenotifications@github.com, wrote:

Pretty sure it's known as a "sub district"

Stephen Keable
www.stephenkeable.co.uk

On 27 Aug 2015, at 18:23, Chris Blanchardnotifications@github.comwrote:

That's an interesting use case.

I'm struggling to come up with an a simple name that encapsulates what it does. subOutcode is better than all the ones I can think of

I suppose as long as the method is well documented in the readme it won't be the end of the world if a suitable name isn't found

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Reply to this email directly or view it on GitHub.

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[stephenkeable]

I work at Allies Computing where they've been working with postcodes for over 20 years. You tend to pick up the terminology without even trying :)

[cblanc]

Perfect. Thanks for the tip @stephenkeable

If you're ever looking for work around London, please allow me to buy you a coffee :D

Also, I do apologise if I'm stepping out of line :-)

[billinghamj]

Oh actually, "sub district" would mean with the number. So I think it should probably work like this:

For outcodes ending with a number:

• district - returns outcode without the number
• subDistrict - returns outcode as-is

For outcodes not ending with a number:

• district - returns outcode as-is
• subDistrict - returns null

This would then allow you to do !postcode.subDistrict() to determine if it is a London high density district or not.

Just needs to be carefully documented.

outcode would continue to work exactly as-is.

[stephenkeable]

The outcode without the number is a Postcode Area not a district.

For NR14 7PZ

NR14 = Outcode
7PZ = Incode

NR = Postcode area
NR14 = Postcode district
NR14 7 = Postcode sector
PZ = Postcode unit

If NR1 ever got too crowded they might create NR1W and NR1E as West and East “Sub districts”.

Not sure what Royal Mail will do should two digit postcode districts need to be sub divided.

On 28 Aug 2015, at 08:29, James Billingham notifications@github.com wrote:

Oh actually, "sub district" would mean with the number. So I think it should probably work like this:

For outcodes ending with a number:

district - returns outcode without the number
subDistrict - returns outcode as-is
For outcodes not ending with a number:

district - returns outcode without the number
subDistrict - returns null
This would then allow you to do !postcode.subDistrict to determine if it is a London high density district or not.

Just needs to be carefully documented.

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[billinghamj]

Yup. That's how it's implemented in the library. Examples are in the readme :)