add webxdc selfAddr/notify/href/ratelimit APIs (M2/M3)

[r10s]

the following task are open to complete M2/M3 proposal desktop-sided:

• change window.webxdc.selfAddr to "self_addr" property returned by dc_msg_get_webxdc_info()

• add and set window.webxdc.sendUpdateInterval to "send_update_interval" property returned by dc_msg_get_webxdc_info()

• add and set window.webxdc.sendUpdateMaxSize to "send_update_max_size" property returned by dc_msg_get_webxdc_info()

• when tapping an webxdc-info-message (dc_msg_get_info_type() returns DC_INFO_WEBXDC_INFO_MESSAGE), open the webxdc-app directly, do not move up (instead, the app menu should provide "Show in Chat, cmp add "show in chat" to webxdc menu deltachat-android#3447, but that can also be done later)

• when opening the webxdc-app from a webxdc-info-message, check dc_msg_get_webxdc_href(). if set, open the app with sth://base/HREF instead of sth://base/index.html
  if the app is already open, make sure, the location is changed (probably the same way), in any case, JavaScript's location properties should be set appropriate and hashchange should be fired as needed

• listen to event DC_EVENT_INCOMING_WEBXDC_NOTIFY. on receiving, add a notification with text set to "APPNAME: TEXT"; TEXT comes from the event. note, that the msg_id from the event may refer to a webxdc-instance or a webxdc-info-message (in the latter case, use get_parent() to get the instance)

jsonrpc types should be similar; if sth. is missing there, this is another task.

for reference, new spec is available already at https://github.com/webxdc/website/tree/next-main/src-docs/spec (

finally, make sure, the webxdc app does not exit when descr is left out, see #4359

corresponding Android / iOS PR: deltachat/deltachat-android#3438 , deltachat/deltachat-android#3449, deltachat/deltachat-ios#2412

[Simon-Laux]

note for person implementing this: for updating/changing webxdc href/url the location change needs to be done in the iframe.

[WofWca]

when tapping an webxdc-info-message, open the webxdc-app directly

IDK about the security of this. Do we want to open apps without the user expecting it?

[r10s]

thanks for the thought!

however, it has an app icon etc, no network etc. it is fine to start directly. if that is unexpected for existing users, ppl will learn it. also, the old indirection has barely prevented ppl from opening the app, when they already tapped curiously the info-message :)