request_interceptor.md

RequestInterceptor

Translations: 简体中文

Sketch intercepts the execution process of ImageRequest through RequestInterceptor, and you can use this to change the input and output of the execution process.

First implement the RequestInterceptor interface to define your RequestInterceptor, as follows:

class MyRequestInterceptor : RequestInterceptor {

    // If the current RequestInterceptor will modify the returned results and is only used for some requests, then please give a unique key to build the cache key, otherwise give null
    override val key: String? = null

    // Used for sorting, the larger the value, the further back in the list. The value range is 0 ~ 100. Usually zero. Only EngineRequestInterceptor can be 100
    override val sortWeight: Int = 0

    override suspend fun intercept(chain: Chain): Result<ImageData> {
        // Disable memory caching for all requests
        val newRequest = chain.request.newRequest {
            memoryCachePolicy(CachePolicy.DISABLED)
        }
        return chain.proceed(newRequest)
    }
}

1. MyRequestInterceptor demonstrates a case where all requests are prohibited from using the memory cache
2. If you want to modify the return result, just intercept the result returned by the proceed method and return a new ImageData
3. If you don’t want to execute the request anymore, just don’t execute the proceed method.

Then register your RequestInterceptor as follows:

/* Register for all ImageRequests */
class MyApplication : Application(), SketchFactory {

    override fun createSketch(): Sketch {
        return Sketch.Builder(this).apply {
            components {
                addRequestInterceptor(MyRequestInterceptor())
            }
        }.build()
    }
}

/* Register for a single ImageRequest */
imageView.displayImage("https://www.sample.com/image.jpg") {
    components {
        addRequestInterceptor(MyRequestInterceptor())
    }
}