Mobile app developers FAQ #

Short answers to the questions app developers ask most. Each answer links to the page that explains it.

Contents #

1. Connecting
2. Reading content
3. Writing content
4. Platform and tooling

Connecting #

My request answers 401 with an empty body. Why? No valid credential reached PHP. Without one, the REST API answers 401 with the header WWW-Authenticate: OAuth realm='Exponential REST' and no body (seen on the demonstration server). Check the header name and scheme, and whether a proxy drops Authorization (The Authorization header and proxies).

Should my app call v1 or v2? Reads answer the same at both; writes exist at v2 only. New apps can use v2 throughout (API versions v1 and v2).

Does the OAuth server support PKCE or public clients? No. The token endpoint requires client_secret and supports the grants authorization_code and refresh_token only. Keep the secret on a server (A back end for your app).

Can I ship a personal API key inside my app? No. A key belongs to one user, acts as that user and is meant for that user's own scripts. Anyone who unpacks the app would have it (Personal API keys for tools).

Does the app get the state parameter back from the authorize page? No. The authorize view says "state, not implemented yet". Correlate the redirect yourself (OAuth2 authorization code flow).

How long does a token live? rest.ini [OAuthSettings] TokenTTL, one hour by default; the token answer says so in expires_in (OAuth2 authorization code flow).

Reading content #

Where is node 2, and which node should my app start from? Node 2 is the root of the content tree in a standard installation. Ask the editors for the folder your app shows, and prefer its remote id over its number (Node ids, remote ids and deep links).

Why does a list return only ten items? The default limit of the list route is 10. Add /offset/<n>/limit/<n> (Listing children and pagination).

Why are my fields missing from the list? Lists give metadata only, unless you add ?ResponseGroups=Fields (Response groups).

How do I get an image in the size of my screen? REST gives the original file path only. Ask for an alias URL with expimage::url (Image aliases for screen sizes).

Is there a search route? Not in REST. The remote services have expsearch::search (Searching content).

How do I read another language? Add ?Translation=<locale> (for example ger-DE) to node, object and field reads (Multilingual content).

My article text has lost its formatting. Rich text fields are given as plain text in REST answers. See Rich text in apps.

Writing content #

Can the app update an existing item through REST? Not yet: the update route checks content/edit and then answers 501. Use expnode::update (Writing through expservices).

My create answers 400. languageLocale is missing, or parentNodeID or classIdentifier is missing or unknown (Creating and removing content).

Can users upload photos from the app? No documented route takes a file from a device (Files and uploads).

Platform and tooling #

Is there an SDK? No. There are shell and Python clients for expservices and hand-written client snippets for other platforms (Mobile app developers: start here).

Is expsite_app a mobile app framework? No. It is the place for a site project's design overrides and settings, layered over the simple design (its README.md).

My browser app gets a CORS error. Exponential sends no CORS headers. Serve the app from the same origin or add the headers at the web server (Web apps, CORS and CSP).

Where do I test without breaking a real site? A local installation of your own is best; a public demo may not have every API active (Testing).

Where do I ask or report? The help's Report an error page and When something goes wrong; the server-side FAQ is Application creators: frequently asked questions.

Related pages #

• Mobile app developers: start here
• What the APIs do not do
• Mobile app developers glossary
• Free documentation: this page is free to copy, translate and improve under the GNU FDL 1.3.