JSONStore - Objective-C API

improve this page | report issue

Follow along with the code sample:

missing_alt
  1. Download the compressed file with the code sample that is associated with this tutorial.
  2. Open the Basic.m file at JSONStoreAPINativeiOS/Examples/Basic.m. The sample image provides context.
  3. Run the application by using Xcode. On the top bar, look for Product and then select Test. Alternatively, you can use the keyboard shortcut (⌘U).

Note: The code sample uses the built-in Unit Test framework of the Xcode IDE. Explaining how this framework works is beyond the scope of this tutorial.

Code Sample Walkthough

    NSError* error = nil;
    [[JSONStore sharedInstance] destroyDataAndReturnError:&error];
    JSONStoreCollection* people = [[JSONStoreCollection alloc]
                                   initWithName:@"people"];
    [people setSearchField:@"name"
                  withType:JSONStore_String];
    [people setSearchField:@"age"
                  withType:JSONStore_Integer];
    [[JSONStore sharedInstance] openCollections:@[people]
                                    withOptions:nil
                                          error:nil];
    NSArray* data = @[@{@"name" : @"carlos", @"age" : @20},
                      @{@"name" : @"mike", @"age" : @30}];
    [people addData:data andMarkDirty:NO
        withOptions:nil
              error:nil];
    NSArray *actualResults = [people findAllWithOptions:nil
                                                  error:nil];
    NSArray* expectedResults =
    @[@{ @"_id" : @1,
         @"json" : @{@"name" : @"carlos", @"age" : @20}},
      @{ @"_id" : @2,
         @"json" : @{@"name" : @"mike",   @"age" : @30}}];
    XCTAssertEqualObjects(actualResults, expectedResults);

If an error occurs, the error variable contains information about the error, such as the error code. Otherwise, it remains nil.

The destroy API removes all JSONStore content from the application. It is used here to start with no data. Doing it this way ensures that the output is predictable in the code sample.

To persist data, you must first define at least one collection. These collections are entities that hold data. You can see here the definition of a collection that is called people.

Search fields are fields that are indexed inside a collection. You can use those fields when you search for data that is inside a collection.
You can see here the definition of two search fields:

  • name (string)
  • age (integer)

The data types, such as string, integer, number, boolean, are used to better store input data.

The open API is used to open one or more collections. If the collection was never opened before, a file is created on the file system to persist data that is inside the collection. Before the operation finishes, an accessor to that file is created.
The accessor allows the caller to call collection-level APIs such as add and findAll, which are shown later in this code sample walkthrough.

The data that is stored inside the people collection is defined here. Notice that the data is a hardcoded array of two JSON objects with key value pairs for name and age. This data can be acquired from multiple sources (for example: Network Request, File I/O, User Input).

The collection accessor provides access to store data inside the people collection. The input data must be in JSON format.

There are a couple of different ways to find documents inside a JSONStore collection (for example: find, findById).
The easiest way, and the way that is shown here, is by using the findAll API. This method returns all the data that is stored inside a collection.

Data that is stored inside a collection is called a document. Documents have _id and json key value pairs. The _id pair is an internal identifier that is added automatically when data is added. The json pair contains all the data that was added.

Sample application

Click to download Studio project.
Click to download Native project.

Expected Output

missing_alt

To execute the tests, select Product > Test.
When the tests are executed, the output looks similar to the sample image.
The green check mark next to the test indicates that everything is working as expected.

For more information

For more information about JSONStore, see the product user documentation.

Last modified on November 09, 2016