1 files changed, 82 insertions, 29 deletions

diff --git a/packages/instant/src/index.umd.ts b/packages/instant/src/index.umd.ts
index 5010347b3..3a8694d6a 100644
--- a/packages/instant/src/index.umd.ts
+++ b/packages/instant/src/index.umd.ts
@@ -5,40 +5,50 @@ import * as ReactDOM from 'react-dom';
 import { DEFAULT_ZERO_EX_CONTAINER_SELECTOR, INJECTED_DIV_CLASS, INJECTED_DIV_ID } from './constants';
 import { ZeroExInstantOverlay, ZeroExInstantOverlayProps } from './index';
 import { assert } from './util/assert';
+import { util } from './util/util';
 
-export const render = (props: ZeroExInstantOverlayProps, selector: string = DEFAULT_ZERO_EX_CONTAINER_SELECTOR) => {
-    assert.isValidOrderSource('orderSource', props.orderSource);
-    if (!_.isUndefined(props.defaultSelectedAssetData)) {
-        assert.isHexString('defaultSelectedAssetData', props.defaultSelectedAssetData);
+const isInstantRendered = (): boolean => !!document.getElementById(INJECTED_DIV_ID);
+
+const validateInstantRenderConfig = (config: ZeroExInstantConfig, selector: string) => {
+    assert.isValidOrderSource('orderSource', config.orderSource);
+    if (!_.isUndefined(config.defaultSelectedAssetData)) {
+        assert.isHexString('defaultSelectedAssetData', config.defaultSelectedAssetData);
+    }
+    if (!_.isUndefined(config.additionalAssetMetaDataMap)) {
+        assert.isValidAssetMetaDataMap('additionalAssetMetaDataMap', config.additionalAssetMetaDataMap);
     }
-    if (!_.isUndefined(props.additionalAssetMetaDataMap)) {
-        assert.isValidAssetMetaDataMap('props.additionalAssetMetaDataMap', props.additionalAssetMetaDataMap);
+    if (!_.isUndefined(config.defaultAssetBuyAmount)) {
+        assert.isNumber('defaultAssetBuyAmount', config.defaultAssetBuyAmount);
     }
-    if (!_.isUndefined(props.defaultAssetBuyAmount)) {
-        assert.isNumber('props.defaultAssetBuyAmount', props.defaultAssetBuyAmount);
+    if (!_.isUndefined(config.networkId)) {
+        assert.isNumber('networkId', config.networkId);
     }
-    if (!_.isUndefined(props.networkId)) {
-        assert.isNumber('props.networkId', props.networkId);
+    if (!_.isUndefined(config.availableAssetDatas)) {
+        assert.areValidAssetDatas('availableAssetDatas', config.availableAssetDatas);
     }
-    if (!_.isUndefined(props.availableAssetDatas)) {
-        assert.areValidAssetDatas('availableAssetDatas', props.availableAssetDatas);
+    if (!_.isUndefined(config.onClose)) {
+        assert.isFunction('onClose', config.onClose);
     }
-    if (!_.isUndefined(props.onClose)) {
-        assert.isFunction('props.onClose', props.onClose);
+    if (!_.isUndefined(config.zIndex)) {
+        assert.isNumber('zIndex', config.zIndex);
     }
-    if (!_.isUndefined(props.zIndex)) {
-        assert.isNumber('props.zIndex', props.zIndex);
+    if (!_.isUndefined(config.affiliateInfo)) {
+        assert.isValidAffiliateInfo('affiliateInfo', config.affiliateInfo);
     }
-    if (!_.isUndefined(props.affiliateInfo)) {
-        assert.isValidAffiliateInfo('props.affiliateInfo', props.affiliateInfo);
+    if (!_.isUndefined(config.provider)) {
+        assert.isWeb3Provider('provider', config.provider);
     }
-    if (!_.isUndefined(props.provider)) {
-        assert.isWeb3Provider('props.provider', props.provider);
+    if (!_.isUndefined(config.shouldDisablePushToHistory)) {
+        assert.isBoolean('shouldDisablePushToHistory', config.shouldDisablePushToHistory);
     }
-    if (!_.isUndefined(props.shouldDisableAnalyticsTracking)) {
-        assert.isBoolean('props.shouldDisableAnalyticsTracking', props.shouldDisableAnalyticsTracking);
+    if (!_.isUndefined(config.shouldDisableAnalyticsTracking)) {
+        assert.isBoolean('shouldDisableAnalyticsTracking', config.shouldDisableAnalyticsTracking);
     }
     assert.isString('selector', selector);
+};
+
+// Render instant and return a callback that allows you to remove it from the DOM.
+const renderInstant = (config: ZeroExInstantConfig, selector: string) => {
     const appendToIfExists = document.querySelector(selector);
     assert.assert(!_.isNull(appendToIfExists), `Could not find div with selector: ${selector}`);
     const appendTo = appendToIfExists as Element;
@@ -46,14 +56,57 @@ export const render = (props: ZeroExInstantOverlayProps, selector: string = DEFA
     injectedDiv.setAttribute('id', INJECTED_DIV_ID);
     injectedDiv.setAttribute('class', INJECTED_DIV_CLASS);
     appendTo.appendChild(injectedDiv);
+    const closeInstant = () => {
+        if (!_.isUndefined(config.onClose)) {
+            config.onClose();
+        }
+        appendTo.removeChild(injectedDiv);
+    };
     const instantOverlayProps = {
-        ...props,
-        onClose: () => {
-            appendTo.removeChild(injectedDiv);
-            if (!_.isUndefined(props.onClose)) {
-                props.onClose();
-            }
-        },
+        ...config,
+        // If we are using the history API, just go back to close
+        onClose: () => (config.shouldDisablePushToHistory ? closeInstant() : window.history.back()),
     };
     ReactDOM.render(React.createElement(ZeroExInstantOverlay, instantOverlayProps), injectedDiv);
+    return closeInstant;
+};
+
+export interface ZeroExInstantConfig extends ZeroExInstantOverlayProps {
+    shouldDisablePushToHistory?: boolean;
+}
+
+export const render = (config: ZeroExInstantConfig, selector: string = DEFAULT_ZERO_EX_CONTAINER_SELECTOR) => {
+    validateInstantRenderConfig(config, selector);
+    if (config.shouldDisablePushToHistory) {
+        if (!isInstantRendered()) {
+            renderInstant(config, selector);
+        }
+        return;
+    }
+    // Before we render, push to history saying that instant is showing for this part of the history.
+    window.history.pushState({ zeroExInstantShowing: true }, '0x Instant');
+    let removeInstant = renderInstant(config, selector);
+    // If the integrator defined a popstate handler, save it to __zeroExInstantIntegratorsPopStateHandler
+    // unless we have already done so on a previous render.
+    const anyWindow = window as any;
+    if (window.onpopstate && !anyWindow.__zeroExInstantIntegratorsPopStateHandler) {
+        anyWindow.__zeroExInstantIntegratorsPopStateHandler = window.onpopstate.bind(window);
+    }
+    const integratorsOnPopStateHandler = anyWindow.__zeroExInstantIntegratorsPopStateHandler || util.boundNoop;
+    const onPopStateHandler = (e: PopStateEvent) => {
+        integratorsOnPopStateHandler(e);
+        const newState = e.state;
+        if (newState && newState.zeroExInstantShowing) {
+            // We have returned to a history state that expects instant to be rendered.
+            if (!isInstantRendered()) {
+                removeInstant = renderInstant(config, selector);
+            }
+        } else {
+            // History has changed to a different state.
+            if (isInstantRendered()) {
+                removeInstant();
+            }
+        }
+    };
+    window.onpopstate = onPopStateHandler;
 };