Build and Run
Description — Build and run a starter app to validate your install of Couchbase Lite on C
- Steps in Getting Started
-
Install | Build
Verify Install
Now you have Couchbase Lite for C installed, you can verify that your apps build correctly.
Enter the C code from Example 1 into your editor of choice and build it.
Running it will create a database, add a document, retrieve the document, update the document and then delete the document.
// Purpose-- provide an overview of available crud and sync functionality
//
// Get the database (and create it if it doesn't exist)
CBLError err;
CBLDatabase* database = CBLDatabase_Open(FLSTR("mydb"), NULL, &err);
if(!database) {
// Error handling. For brevity, this is truncated in the rest of the snippet
// and omitted in other doc code snippets
fprintf(stderr, "Error opening database (%d / %d)\n", err.domain, err.code);
FLSliceResult msg = CBLError_Message(&err);
fprintf(stderr, "%.*s\n", (int)msg.size, (const char *)msg.buf);
FLSliceResult_Release(msg);
return;
}
// All CRUD operations must be carried out via a collection (for backwards compatibility
// the old CBLDatabase_ API will automatically use the default collection). This is a quick
// API to explicitly get the default collection.
CBLCollection* collection = CBLDatabase_DefaultCollection(database, &err);
// The lack of 'const' indicates this document is mutable
// Create a new document (i.e. a record) in the database
CBLDocument* mutableDoc = CBLDocument_Create();
FLMutableDict properties = CBLDocument_MutableProperties(mutableDoc);
FLMutableDict_SetFloat(properties, FLSTR("version"), 3.0f);
// Save it to the database
if(!CBLCollection_SaveDocument(collection, mutableDoc, &err)) {
// Failed to save, do error handling as above
return;
}
// Since we will release the document, make a copy of the ID since it
// is an internal pointer. Whenever we create or get an FLSliceResult
// or FLStringResult we will need to free it later too!
FLString id = CBLDocument_ID(mutableDoc);
CBLDocument_Release(mutableDoc);
// Update a document
mutableDoc = CBLCollection_GetMutableDocument(collection, id, &err);
if(!mutableDoc) {
// Failed to retrieve, do error handling as above. NOTE: error code 0 simply means
// the document does not exist.
return;
}
properties = CBLDocument_MutableProperties(mutableDoc);
FLMutableDict_SetString(properties, FLSTR("language"), FLSTR("C"));
if(!CBLCollection_SaveDocument(collection, mutableDoc, &err)) {
// Failed to save, do error handling as above
return;
}
// Note const here, means readonly
const CBLDocument* docAgain = CBLCollection_GetDocument(collection, id, &err);
if(!docAgain) {
// Failed to retrieve, do error handling as above. NOTE: error code 0 simply means
// the document does not exist.
return;
}
// No copy this time, so no release later (notice it is not FLStringResult this time)
FLString retrievedID = CBLDocument_ID(docAgain);
FLDict retrievedProperties = CBLDocument_Properties(docAgain);
FLString retrievedLanguage = FLValue_AsString(FLDict_Get(retrievedProperties, FLSTR("language")));
printf("Document ID :: %.*s\n", (int)retrievedID.size, (const char *)retrievedID.buf);
printf("Learning %.*s\n", (int)retrievedLanguage.size, (const char *)retrievedLanguage.buf);
CBLDocument_Release(mutableDoc);
CBLDocument_Release(docAgain);
// Create a query to fetch documents of type SDK
int errorPos;
CBLQuery* query = CBLDatabase_CreateQuery(database, kCBLN1QLLanguage, FLSTR("SELECT * FROM _ WHERE type = \"SDK\""), &errorPos, &err);
if(!query) {
// Failed to create query, do error handling as above
// Note that errorPos will contain the position in the N1QL string
// that the parse failed, if applicable
return;
}
CBLResultSet* result = CBLQuery_Execute(query, &err);
if(!result) {
// Failed to run query, do error handling as above
return;
}
CBLResultSet_Release(result);
CBLQuery_Release(query);
// Create replicator to push and pull changes to and from the cloud
CBLEndpoint* targetEndpoint = CBLEndpoint_CreateWithURL(FLSTR("ws://localhost:4984/getting-started-db"), &err);
if(!targetEndpoint) {
// Failed to create endpoint, do error handling as above
return;
}
CBLReplicatorConfiguration replConfig;
CBLAuthenticator* basicAuth = CBLAuth_CreatePassword(FLSTR("john"), FLSTR("pass"));
memset(&replConfig, 0, sizeof(replConfig));
replConfig.database = database;
replConfig.endpoint = targetEndpoint;
replConfig.authenticator = basicAuth;
CBLReplicator* replicator = CBLReplicator_Create(&replConfig, &err);
CBLAuth_Free(basicAuth);
CBLEndpoint_Free(targetEndpoint);
if(!replicator) {
// Failed to create replicator, do error handling as above
return;
}
// Assume a function like the simple following
//
// static void getting_started_change_listener(void* context, CBLReplicator* repl, const CBLReplicatorStatus* status) {
// if(status->error.code != 0) {
// printf("Error %d / %d\n", status->error.domain, status->error.code);
// }
// }
CBLListenerToken* token = CBLReplicator_AddChangeListener(replicator, getting_started_change_listener, NULL);
CBLReplicator_Start(replicator, false);
// Later, stop and release the replicator