StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

PO
primarykey
Id
6090777
data
AcceptedAnswerId
0
AnswerCount
0
ClosedDate
CommentCount
1
CommunityOwnedDate
CreationDate
2011-05-22T21:05:08.930
FavoriteCount
0
LastActivityDate
2011-05-22T21:05:08.930
LastEditDate
LastEditorUserId
0
OwnerUserId
83805
ParentId
6090599
PostTypeId
2
Score
14
ViewCount
0
LastEditorDisplayName
text
Body
You need to write a <code>showJSON</code> and <code>readJSON</code> method, for your type, that builds your Haskell values out of the JSON format. The JSON package will take care of parsing the raw string into a <a href="http://hackage.haskell.org/packages/archive/json/0.4.4/doc/html/src/Text-JSON-Types.html#JSValue" rel="noreferrer"><code>JSValue</code></a> for you. Your tweet will be a <code>JSObject</code> containing a map of strings, most likely. <ul> <li>Use <code>show</code> to look at the JSObject, to see how the fields are laid out.</li> <li>You can lookup each field using <code>get_field</code> on the <code>JSObject</code>. </li> <li>You can use <code>fromJSString</code> to get a regular Haskell strings from a <code>JSString</code>.</li> </ul> Broadly, you'll need something like, <pre><code>{-# LANGUAGE RecordWildCards #-} import Text.JSON import Text.JSON.Types instance JSON Tweet where readJSON (JSObject o) = return $ Tweet { .. } where from_user = grab o "from_user" to_user_id = grab o "to_user_id" profile_image_url = grab o "proile_image_url" created_at = grab o "created_at" id_str = grab o "id_str" source = grab o "source" to_user_id_str = grab o "to_user_id_str" from_user_id_str = grab o "from_user_id_str" from_user_id = grab o "from_user_id" text = grab o "text" metadata = grab o "metadata" grab o s = case get_field o s of Nothing -> error "Invalid field " ++ show s Just (JSString s') -> fromJSString s' </code></pre> Note, I'm using the rather cool wild cards language extension. Without an example of the JSON encoding, there's not much more I can advise. <hr> Related You can find example instances for the JSON encoding via instances <ul> <li><a href="http://hackage.haskell.org/packages/archive/json/0.4.4/doc/html/src/Text-JSON.html#JSON" rel="noreferrer">in the source</a>, for simple types. Or in other packages that depend on json. </li> <li>An instance for AUR messages <a href="http://hackage.haskell.org/packages/archive/archlinux/0.3.3/doc/html/src/Distribution-ArchLinux-AUR.html#AURInfo" rel="noreferrer">is here</a>, as a (low level) example.</li> </ul>
Tags
Title
singulars
PostAcceptedAnswerId
1. This table or related slice is empty.
PostParentId
1. POParsing JSON string into record in Haskell
 singulars
 PostTypePostTypeId
 PTQuestion
PostTypePostTypeId
1. PTAnswer
UserLastEditorUserId
1. This table or related slice is empty.
UserOwnerUserId
1. USDon Stewart
plurals
PostLinksPostIdRelatedPostId
1. This table or related slice is empty.
PostLinksRelatedPostIdPostId
1. This table or related slice is empty.
PostsAcceptedAnswerId
1. POParsing JSON string into record in Haskell
 singulars
 PostTypePostTypeId
 PTQuestion
PostsParentIdCreationDate
1. This table or related slice is empty.
VotesPostIdCreationDate
1. VO
 singulars
 PostPostId
 PO
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
2. VO
 singulars
 PostPostId
 PO
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
3. VO
 singulars
 PostPostId
 PO
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
CommentsPostId
1. COSuperb, thanks for the detailed reply that worked a treat. Is there any way I can talk to the package authors to perhaps put examples like this (with credit to you obviously) in the documentation?
 singulars
 PostPostId
 PO
 UserUserId
 USdjhworld

Querying!

Guidance

A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.