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package com.pitchedapps.frost.injectors
import android.webkit.WebView
import com.pitchedapps.frost.utils.L
import com.pitchedapps.frost.web.FrostWebViewClient
import io.reactivex.Observable
import io.reactivex.android.schedulers.AndroidSchedulers
import io.reactivex.subjects.SingleSubject
import org.apache.commons.text.StringEscapeUtils
import java.util.*
class JsBuilder {
private val css = StringBuilder()
private val js = StringBuilder()
private var tag: String? = null
fun css(css: String): JsBuilder {
this.css.append(StringEscapeUtils.escapeEcmaScript(css))
return this
}
fun js(content: String): JsBuilder {
this.js.append(content)
return this
}
fun single(tag: String): JsBuilder {
this.tag = tag
return this
}
fun build() = JsInjector(toString())
override fun toString(): String {
val builder = StringBuilder().append("!function(){")
if (css.isNotBlank()) {
val cssMin = css.replace(Regex("\\s*\n\\s*"), "")
builder.append("var a=document.createElement('style');a.innerHTML='$cssMin';document.head.appendChild(a);")
}
if (js.isNotBlank())
builder.append(js)
var content = builder.append("}()").toString()
if (tag != null) content = singleInjector(tag!!, content)
return content
}
private fun singleInjector(tag: String, content: String) = StringBuilder().apply {
val name = "_frost_${tag.toLowerCase(Locale.CANADA)}"
append("if (!window.hasOwnProperty(\"$name\")) {")
append("console.log(\"Registering $name\");")
append("window.$name = true;")
append(content)
append("}")
}.toString()
}
/**
* Contract for all injectors to allow it to interact properly with a webview
*/
interface InjectorContract {
fun inject(webView: WebView) = inject(webView, null)
fun inject(webView: WebView, callback: ((String) -> Unit)?)
/**
* Toggle the injector (usually through Prefs
* If false, will fallback to an empty action
*/
fun maybe(enable: Boolean): InjectorContract = if (enable) this else JsActions.EMPTY
}
/**
* Helper method to inject multiple functions simultaneously with a single callback
*/
fun WebView.jsInject(vararg injectors: InjectorContract, callback: ((Array<String>) -> Unit) = {}) {
val validInjectors = injectors.filter { it != JsActions.EMPTY }
if (validInjectors.isEmpty()) return callback(emptyArray())
val observables = Array(validInjectors.size, { SingleSubject.create<String>() })
L.d("Injecting ${observables.size} items")
Observable.zip<String, Array<String>>(observables.map(SingleSubject<String>::toObservable),
{ it.map(Any::toString).toTypedArray() })
.subscribeOn(AndroidSchedulers.mainThread()).subscribe({ callback(it) })
(0 until validInjectors.size).forEach { i -> validInjectors[i].inject(this, { observables[i].onSuccess(it) }) }
}
fun FrostWebViewClient.jsInject(vararg injectors: InjectorContract, callback: ((Array<String>) -> Unit) = {}) = webCore.jsInject(*injectors, callback = callback)
/**
* Wrapper class to convert a function into an injector
*/
class JsInjector(val function: String) : InjectorContract {
override fun inject(webView: WebView, callback: ((String) -> Unit)?) {
webView.evaluateJavascript(function, { value -> callback?.invoke(value) })
}
}
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