contentstack/contentstack-ios

iOS SDK for Contentstack

Contentstack is a headless CMS with an API-first approach. It is a CMS that developers can use to build powerful cross-platform applications in their favorite languages. Build your application frontend, and Contentstack will take care of the rest. Read More.

Contentstack provides iOS SDK to build application on top of iOS. Given below is the detailed guide and helpful resources to get started with our iOS SDK.

Prerequisite

Latest Xcode and Mac OS X

Setup and Installation

To use this SDK on iOS platform, you will have to install the SDK according to the steps given below.

CocoaPods

Add the following line to your Podfile:
pod 'Contentstack'
Run pod install, and you should now have the latest Contentstack release.

Import Header/Module

You can import header file in Objective-C project as:

Objective-C
```
 #import <Contentstack/Contentstack.h>;
```
Swift
```
 import Contentstack
```
Key Concepts for using Contentstack

Stack

A stack is like a container that holds the content of your app. Learn more about Stacks.

Content Type

Content type lets you define the structure or blueprint of a page or a section of your digital property. It is a form-like page that gives Content Managers an interface to input and upload content. Read more.

Entry

An entry is the actual piece of content created using one of the defined content types. Learn more about Entries.

Asset

Assets refer to all the media files (images, videos, PDFs, audio files, and so on) uploaded to Contentstack. These files can be used in multiple entries. Read more about Assets.

Environment

A publishing environment corresponds to one or more deployment servers or a content delivery destination where the entries need to be published. Learn how to work with Environments.

Contentstack iOS SDK: 5-minute Quickstart

Initializing your SDK

To start using the SDK in your application, you will need to initialize the stack by providing the required keys and values associated with them:

Objective-C

 Stack *stack = [Contentstack stackWithAPIKey: API_KEY accessToken: ACCESS_TOKEN environmentName: ENVIRONMENT];

Swift
```
 let stack:Stack = Contentstack.stackWithAPIKey(API_KEY, accessToken: ACCESS_TOKEN, environmentName: ENVIRONMENT)
```
To get the api credentials mentioned above, you need to log into your Contentstack account and then in your top panel navigation, go to Settings -> Stack to view both your API Key and your Access Token

The stack object that is returned is a Contentstack client object, which can be used to initialize different modules and make queries against our Content Delivery API. The initialization process for each module is explained in the following section.

Querying content from your stack

To fetch all entries of of a content type, use the query given below:

Objective-C

 ContentType *contentTypeObject = [stack contentTypeWithName:@"my_content_type"];

 Query *queryObject = [contentTypeObj query];

Swift

 var contentTypeObject:ContentType = stack.contentTypeWithName("my_content_type")

 var queryObject:Query = contentTypeObj.query()

To fetch a specific entry from a content type, use the following query:

Objective-C

 ContentType * contentTypeObject = [stack contentTypeWithName:@"my_content_type"];

 Entry *entryObject  = [contentTypeObject entryWithUID:@"ENTRY_UID"];

Swift

 var contentTypeObject:ContentType = stack.contentTypeWithName("my_content_type")

 var entryObject:Entry = contentTypeObject.entryWithUID("ENTRY_UID")

Advanced Queries

You can query for content types, entries, assets and more using our iOS API Reference.

iOS API Reference Doc

Working with Images

We have introduced Image Delivery APIs that let you retrieve images and then manipulate and optimize them for your digital properties. It lets you perform a host of other actions such as crop, trim, resize, rotate, overlay, and so on.

For example, if you want to crop an image (with width as 300 and height as 400), you simply need to append query parameters at the end of the image URL, such as, https://images.contentstack.io/v3/assets/download?crop=300,400. There are several more parameters that you can use for your images.

Read Image Delivery API documentation.

You can use the Image Delivery API functions in this SDK as well. Here are a few examples of its usage in the SDK.

Objective-C

 /* set the image quality to 100 */
 NSDictionary *params = [[NSDictionary alloc] initWithObjectsAndKeys:[NSNumber numberWithInt:100], @"quality", nil];
 NSString *transformedUrl = [stack imageTransformWithUrl:imageURL andParams:params];

 /* resize the image by specifying width and height */
 NSDictionary *params = [[NSDictionary alloc] initWithObjectsAndKeys:[NSNumber numberWithInt:100], @"width", [NSNumber numberWithInt:100], @"height", nil];
 NSString *transformedUrl = [stack imageTransformWithUrl:imageURL andParams:params];

 /* enable auto optimization for the image */
 NSDictionary *params = [[NSDictionary alloc] initWithObjectsAndKeys:@"webp", @"auto", nil];
 NSString *transformedUrl = [stack imageTransformWithUrl:imageURL andParams:params];

Swift

 /* set the image quality to 100 */
 let params:[String : AnyObject?] = [
     "quality":100 as AnyObject
 ];
 let transformedUrl:String = stack.imageTransformation(withUrl: imageURL, andParams: params);

 /* resize the image by specifying width and height */
 let params:[String : AnyObject?] = [
     "width":100 as AnyObject,
     "height":100 as AnyObject,
 ];
 let transformedUrl:String = stack.imageTransformation(withUrl: imageURL, andParams: params);

 let params:[String : AnyObject?] = [
     "auto":"webp" as AnyObject
 ];
 let transformedUrl:String = stack.imageTransformation(withUrl: imageURL, andParams: params);

iOS API Reference Doc

Using the Sync API with iOS SDK

The Sync API takes care of syncing your Contentstack data with your app and ensures that the data is always up-to-date by providing delta updates. Contentstack’s iOS SDK supports Sync API, which you can use to build powerful apps. Read through to understand how to use the Sync API with Contentstack iOS SDK.

Initial Sync

The Initial Sync process performs a complete sync of your app data. It returns all the published entries and assets of the specified stack in response.

To start the Initial Sync process, use the syncStack method.

Objective-C

 [stack sync:^(SyncStack * _Nullable syncStack, NSError* _Nullable error) {
     //error for any error description
     //syncStack for SyncStack
     //syncStack.syncToken: contains token for next sync Store this token For next sync
     //syncStack.paginationToken: contains token for next sync page this token for next sync
     //syncStack.items: contains sync data
     if (syncStack.paginationToken != nil) {
         [[NSUserDefaults standardUserDefaults]  setValue:syncStack.syncToken forKey:@"Token"];
     }else {
         [[NSUserDefaults standardUserDefaults]  setValue:syncStack.syncToken forKey:@"SyncToken"];
     }
 }];

Swift

 stack.sync({ (syncStack:SyncStack, error:NSError)  in

     //error for any error description
     //syncStack for SyncStack
     //syncStack.syncToken: contains token for next sync Store this token For next sync
     //syncStack.paginationToken: contains token for next sync page this token for next sync
     //syncStack.items: contains sync data
     If let token = syncStack.paginationToken {
         UserDefault.standard.setValue(token, forKey:"PaginationToken")
     }else if let token = syncStack.syncToken {
         UserDefault.standard.setValue(token, forKey:"SyncToken")
     }
 })

The response also contains a sync token, which you need to store, since this token is used to get subsequent delta updates later, as shown in the Subsequent Sync section below.

You can also fetch custom results in initial sync by using advanced sync queries.

Sync Pagination

If the result of the initial sync (or subsequent sync) contains more than 100 records, the response would be paginated. It provides pagination token in the response. However, you don’t have to use the pagination token manually to get the next batch; the SDK does that automatically, until the sync is complete.

Pagination token can be used in case you want to fetch only selected batches. It is especially useful if the sync process is interrupted midway (due to network issues, etc.). In such cases, this token can be used to restart the sync process from where it was interrupted.

Objective-C

 [stack syncPaginationToken: <pagination_token> completion:^(SyncStack * _Nullable syncStack, NSError* _Nullable error) {
     //error for any error description
     //syncStack for SyncStack
     //syncStack.syncToken: contains token for next sync Store this token For next sync
     //syncStack.paginationToken: contains token for next sync page this token for next sync
     //syncStack.items: contains sync data
     if (syncStack.paginationToken != nil) {
         [[NSUserDefaults standardUserDefaults]  setValue:syncStack.syncToken forKey:@"Token"];
     }else {
         [[NSUserDefaults standardUserDefaults]  setValue:syncStack.syncToken forKey:@"SyncToken"];
     }
 }];

Swift

 stack.syncPaginationToken(<pagination_token>, completion: { (syncStack:SyncStack, error:NSError)  in
     //error for any error description
     //syncStack for SyncStack
     //syncStack.syncToken: contains token for next sync Store this token for next sync
     //syncStack.paginationToken: contains token for next sync page this token for next sync
     //syncStack.items: contains sync data
     If let token = syncStack.paginationToken {
         UserDefault.standard.setValue(token, forKey:"PaginationToken")
     }else if let token = syncStack.syncToken {
         UserDefault.standard.setValue(token, forKey:"SyncToken")
     }
 })

Subsequent Sync

You can use the sync token (that you receive after initial sync) to get the updated content next time. The sync token fetches only the content that was added after your last sync, and the details of the content that was deleted or updated.

Objective-C

 [stack syncToken: <sync_token> completion:^(SyncStack * _Nullable syncStack, NSError* _Nullable error) {
     //error for any error description
     //syncStack for SyncStack
     //syncStack.syncToken: contains token for next sync Store this token For next sync
     //syncStack.paginationToken: contains token for next sync page this token for next sync
     //syncStack.items: contains sync data
     if (syncStack.paginationToken != nil) {
         [[NSUserDefaults standardUserDefaults]  setValue:syncStack.syncToken forKey:@"PaginationToken"];
     }else {
         [[NSUserDefaults standardUserDefaults]  setValue:syncStack.syncToken forKey:@"SyncToken"];
     }
 }];

Swift

 stack.syncToken(<sync_token>, completion: { (syncStack:SyncStack, error:NSError)  in
     //error for any error description
     //syncStack for SyncStack
     //syncStack.syncToken: contains token for next sync Store this token for next sync
     //syncStack.paginationToken: contains token for next sync page this token for next sync
     //syncStack.items: contains sync data
     If let token = syncStack.paginationToken {
         UserDefault.standard.setValue(token, forKey:"PaginationToken")
     }else if let token = syncStack.syncToken {
         UserDefault.standard.setValue(token, forKey:"SyncToken")
     }
 })

Advance Sync Queries

You can use advanced sync queries to fetch custom results while performing initial sync. Read advanced sync queries documentation.

Helpful Links

The MIT License (MIT)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.