After numerous articles, APIs and youtube videos, i got it to work.
Here's my code with few comments:
View gamesForCategory = db.getView("viewName");
gamesForCategory.setMap(new Mapper() {
@Override
public void map(Map<String, Object> document, Emitter emitter) {
showText("Doing query for: " + categoryID );
if(document.get("name").equals(categoryID)){
Object gamesData = document.get("books"); //get second level array object
List<Object> gamesList = (List<Object>) gamesData; //since it's a list, i
can cast it
for(Object g : gamesList){
Map<String, Object> m = (Map<String, Object>) g;
emitter.emit(m.get("name"), m); //'m.get("name")' is ID for the query
result. 'm' is an object in second level array and will be pushed into the
results
}
}
}
}, "1.0");
View v = db.getView("descriptionsForCategory");
Query q = v.createQuery();
QueryEnumerator rowEnum = q.run();
for (Iterator<QueryRow> it = rowEnum; it.hasNext();) {
QueryRow row = it.next();
Map<String, Object> m = (Map<String, Object>) row.getValue(); //only second
level array objects are in results, so i can cast them to map
showText(m.get("name").toString()); //get any value from map using keys.
}
reede, 11. aprill 2014 16:17.06 UTC+3 kirjutas Mart-Indrek Süld:
>
> Thank you, but it doesn't seem to work. I get NullPointerExceptions from
> the Map. It seems to me this particular predefined map gives access to only
> "Name"key property, but i need access to whole object.
>
> In short - i'd really like to know how to get access to *second level*
> *array* objects properties.
>
> If you'd be able to help me out, i'd be so grateful!
>
> kolmapäev, 9. aprill 2014 16:21.41 UTC+3 kirjutas prasanna kumar:
>>
>> Hi,
>> It may help you
>>
>> com.couchbase.lite.View viewItemsByDate = db.getView("booksForCategory");
>> viewItemsByDate.setMap(new Mapper() {
>>
>> HashMap<String, Object> categories = (HashMap<String, Object>) document
>> .get("categories");
>>
>> @Override
>> public void map(Map<String, Object> document, Emitter emitter) {
>>
>> HashMap<String, String> books= (HashMap<String, String>) categories
>> .get("books");
>>
>> Object createdAt = books.get("name");
>> if (createdAt != null) {
>> emitter.emit(createdAt.toString(), document);
>> }
>> }
>> }, "1.0");
>>
>> //In Query part
>> Query q = v.createQuery();
>> QueryEnumerator rowEnum = q.run();
>> for (Iterator<QueryRow> it = rowEnum; it.hasNext();) {
>> QueryRow row = it.next();
>> //BY USING Getkey method we can get name field
>> Book b = new Book(row.getKey()));
>> //or else we can do like this also
>> HashMap<String, HashMap<String, String>> responsibleHaspMap =
>> (HashMap<String, HashMap<String, String>>) document
>> .getCurrentRevision().getProperty(
>> "categories");
>> responsibleHaspMap
>> .get("books").get("name"));
>> }
>>
>> On Tuesday, April 8, 2014 7:29:31 PM UTC+5:30, Mart-Indrek Süld wrote:
>>>
>>> I'm developing Couchbase Lite on Android and I have a database, what is
>>> initialized according to JSON data file, what looks like this:
>>> {
>>> "categories": [
>>> {
>>> "name": "Financial",
>>> "books": [
>>> {
>>> "name": "Rich dad poor dad"
>>> },
>>> {
>>> "name": "How to stay rich"
>>> }
>>> ]
>>> },
>>> {
>>> "name": "Science",
>>> "books": [
>>> {
>>> "name": "Superman"
>>> },
>>> {
>>> "name": "Green hornet"
>>> }
>>> ]
>>> }
>>> ]
>>> }
>>>
>>> How can I receive the "books"-array and gain access to "name"-value for
>>> certain category?
>>>
>>> I separated all the categories in a database to a separate Documents and
>>> gave them ID according to category name(Is it reasonable to separate them
>>> or it doesn't make any difference?).
>>> For example, if i want to get access to "financial" category i type:
>>> Document d = database.getExistingDocument("financial");
>>> and everything works fine.
>>>
>>> If i want to get all the categories i type:
>>> List<Category> list = new ArrayList<Category>();
>>> Database db = manager.getExistingDatabase(DATABASE_NAME);
>>> Query query = db.createAllDocumentsQuery();
>>> QueryEnumerator rowEnum = query.run();
>>> for (Iterator<QueryRow> it = rowEnum; it.hasNext();) {
>>> QueryRow row = it.next();
>>> Document d = db.getExistingDocument(row.getDocumentId());
>>> list.add(new Category((String) d.getProperty("name")));
>>> }
>>>
>>> But how can i get access to "books"-array?
>>> So far this is what i've come up with (Read APIs and GrocerySync
>>> example):
>>> Document d = db.getExistingDocument(categoryID);
>>> com.couchbase.lite.View viewItemsByDate = db.getView("booksForCategory");
>>> viewItemsByDate.setMap(new Mapper() {
>>> @Override
>>> public void map(Map<String, Object> document, Emitter emitter) {
>>> Object createdAt = document.get("books");
>>> if (createdAt != null) {
>>> emitter.emit(createdAt.toString(), document);
>>> }
>>> }
>>> }, "1.0");
>>> com.couchbase.lite.View v = db.getView("booksForCategory");
>>> Query q = v.createQuery();
>>> QueryEnumerator rowEnum = q.run();
>>> for (Iterator<QueryRow> it = rowEnum; it.hasNext();) {
>>> QueryRow row = it.next();
>>> Book b = new Book(row.getProperty("name"));//???
>>> }
>>> But in my oppinion, it doesen't work correctly and this is not the way
>>> to do it. It returns wrong results and i'm pretty sure this is not how it
>>> should be done.
>>>
>>> (Oh, Do i define "getView("booksForCategory")" once in the constructor
>>> of the DAO or every single time?)
>>>
>>> Could anyone help me and show me how it's done properly? How to properly
>>> get the array of data from the Document so i can get access to properties
>>> using Key's?
>>>
>>> Thanks in advance!
>>>
>>>
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