feature flag approval sending

SignalMessaging/ViewControllers/AttachmentApprovalViewController.swift

@@ -1861,47 +1861,49 @@ class MediaMessageTextToolbar: UIView, UITextViewDelegate {
 
     public func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
 
-        let existingText: String = textView.text ?? ""
-        let proposedText: String = (existingText as NSString).replacingCharacters(in: range, with: text)
-
-        // Don't complicate things by mixing media attachments with oversize text attachments
-        guard proposedText.utf8.count <= kOversizeTextMessageSizeThreshold else {
-            Logger.debug("long text was truncated")
-            self.lengthLimitLabel.isHidden = false
-
-            // `range` represents the section of the existing text we will replace. We can re-use that space.
-            // Range is in units of NSStrings's standard UTF-16 characters. Since some of those chars could be
-            // represented as single bytes in utf-8, while others may be 8 or more, the only way to be sure is
-            // to just measure the utf8 encoded bytes of the replaced substring.
-            let bytesAfterDelete: Int = (existingText as NSString).replacingCharacters(in: range, with: "").utf8.count
+        if !FeatureFlags.sendingMediaWithOversizeText {
+            let existingText: String = textView.text ?? ""
+            let proposedText: String = (existingText as NSString).replacingCharacters(in: range, with: text)
+
+            // Don't complicate things by mixing media attachments with oversize text attachments
+            guard proposedText.utf8.count <= kOversizeTextMessageSizeThreshold else {
+                Logger.debug("long text was truncated")
+                self.lengthLimitLabel.isHidden = false
+
+                // `range` represents the section of the existing text we will replace. We can re-use that space.
+                // Range is in units of NSStrings's standard UTF-16 characters. Since some of those chars could be
+                // represented as single bytes in utf-8, while others may be 8 or more, the only way to be sure is
+                // to just measure the utf8 encoded bytes of the replaced substring.
+                let bytesAfterDelete: Int = (existingText as NSString).replacingCharacters(in: range, with: "").utf8.count
+
+                // Accept as much of the input as we can
+                let byteBudget: Int = Int(kOversizeTextMessageSizeThreshold) - bytesAfterDelete
+                if byteBudget >= 0, let acceptableNewText = text.truncated(toByteCount: UInt(byteBudget)) {
+                    textView.text = (existingText as NSString).replacingCharacters(in: range, with: acceptableNewText)
+                }
 
-            // Accept as much of the input as we can
-            let byteBudget: Int = Int(kOversizeTextMessageSizeThreshold) - bytesAfterDelete
-            if byteBudget >= 0, let acceptableNewText = text.truncated(toByteCount: UInt(byteBudget)) {
-                textView.text = (existingText as NSString).replacingCharacters(in: range, with: acceptableNewText)
+                return false
             }
+            self.lengthLimitLabel.isHidden = true
 
-            return false
-        }
-        self.lengthLimitLabel.isHidden = true
+            // After verifying the byte-length is sufficiently small, verify the character count is within bounds.
+            guard proposedText.count <= kMaxMessageBodyCharacterCount else {
+                Logger.debug("hit attachment message body character count limit")
 
-        // After verifying the byte-length is sufficiently small, verify the character count is within bounds.
-        guard proposedText.count <= kMaxMessageBodyCharacterCount else {
-            Logger.debug("hit attachment message body character count limit")
+                self.lengthLimitLabel.isHidden = false
 
-            self.lengthLimitLabel.isHidden = false
+                // `range` represents the section of the existing text we will replace. We can re-use that space.
+                let charsAfterDelete: Int = (existingText as NSString).replacingCharacters(in: range, with: "").count
 
-            // `range` represents the section of the existing text we will replace. We can re-use that space.
-            let charsAfterDelete: Int = (existingText as NSString).replacingCharacters(in: range, with: "").count
+                // Accept as much of the input as we can
+                let charBudget: Int = Int(kMaxMessageBodyCharacterCount) - charsAfterDelete
+                if charBudget >= 0 {
+                    let acceptableNewText = String(text.prefix(charBudget))
+                    textView.text = (existingText as NSString).replacingCharacters(in: range, with: acceptableNewText)
+                }
 
-            // Accept as much of the input as we can
-            let charBudget: Int = Int(kMaxMessageBodyCharacterCount) - charsAfterDelete
-            if charBudget >= 0 {
-                let acceptableNewText = String(text.prefix(charBudget))
-                textView.text = (existingText as NSString).replacingCharacters(in: range, with: acceptableNewText)
+                return false
             }
-
-            return false
         }
 
         // Though we can wrap the text, we don't want to encourage multline captions, plus a "done" button

SignalMessaging/utils/ThreadUtil.m

@@ -113,7 +113,15 @@ NS_ASSUME_NONNULL_BEGIN
     if ([fullMessageText lengthOfBytesUsingEncoding:NSUTF8StringEncoding] < kOversizeTextMessageSizeThreshold) {
         truncatedText = fullMessageText;
     } else {
-        truncatedText = [fullMessageText ows_truncatedToByteCount:kOversizeTextMessageSizeThreshold];
+        if (SSKFeatureFlags.sendingMediaWithOversizeText) {
+            truncatedText = [fullMessageText ows_truncatedToByteCount:kOversizeTextMessageSizeThreshold];
+        } else {
+            // Legacy iOS clients already support receiving long text, but they assume _any_ body
+            // text is the _full_ body text. So until we consider "rollout" complete, we maintain
+            // the legacy sending behavior, which does not include the truncated text in the
+            // websocket proto.
+            truncatedText = nil;
+        }
         DataSource *_Nullable dataSource = [DataSourceValue dataSourceWithOversizeText:fullMessageText];
         if (dataSource) {
             SignalAttachment *oversizeTextAttachment =

SignalServiceKit/src/Util/FeatureFlags.swift

@@ -0,0 +1,22 @@
+//
+//  Copyright (c) 2019 Open Whisper Systems. All rights reserved.
+//
+
+import Foundation
+
+/// By centralizing feature flags here and documenting their rollout plan, it's easier to review
+/// which feature flags are in play.
+@objc(SSKFeatureFlags)
+public class FeatureFlags: NSObject {
+
+    /// iOS has long supported sending oversized text as a sidecar attachment. The other clients
+    /// simply displayed it as a text attachment. As part of the new cross-client long-text feature,
+    /// we want to be able to display long text with attachments as well. Existing iOS clients
+    /// won't properly display this, so we'll need to wait a while for rollout.
+    /// The stakes aren't __too__ high, because legacy clients won't lose data - they just won't
+    /// see the media attached to a long text message until they update their client.
+    @objc
+    public static var sendingMediaWithOversizeText: Bool {
+        return false
+    }
+}