When using tgram:// combined with other notification types in notifications settings, the tgram-specific notification length limit is applied to all

[leandertolksdorf]

Describe the bug
When a long diff occurs, the notification sent to my notification targets get truncated, removing diff elements and invalidating the json I prepared in the notification body.

Two examples I just checked have a length of about 3200 characters, but not the same.

The issue occurs with the telegram target, as well as an HTTP request target.

Version
0.45.16

To Reproduce

My notification body:

{"watch_url": {{watch_url|tojson}}, "diff": {{diff_added|tojson}}}

The diff that caused the issue:
https://staking-roll-production.up.railway.app/diff/16755df2-fe52-45c3-be13-9dc105661a62#text

Expected behavior
A clear and concise description of what you expected to happen.

The whole diff is submitted in the notification body.

[dgtlmoon]

You dont say which notification target/protocol you are using...

[dgtlmoon]

Can you paste some example apprise URL you are using?

[leandertolksdorf]

@dgtlmoon
I'm using a telegram URL and my own HTTP endpoint:

tgram://xxx/xxx
get://xxx:5000/handle

I just checked with a paste with a notification body {{diff_added|tojson}} and it seems that the diff is cut-off at 3557 characters.

Watch URL (I added the two long lines with numbers to check and both times the same cut-off):
https://paste.fo/raw/01393b9bc961

Diff:
https://staking-roll-production.up.railway.app/diff/9a7eb76a-c40c-4b2b-81a6-5376d33ce083?from_version=1712854181#text

Telegram Notification:

HTTP-Notification:

Details

"(added) 0*********10********20********30********40********50********60********70********80********90********100*******110*******120*******130*******140*******150*******160*******170*******180*******190*******200*******210*******220*******230*******240*******250*******260*******270*******280*******290*******300*******310*******320*******330*******340*******350*******360*******370*******380*******390*******400*******410*******420*******430*******440*******450*******460*******470*******480*******490*******500*******510*******520*******530*******540*******550*******560*******570*******580*******590*******600*******610*******620*******630*******640*******650*******660*******670*******680*******690*******700*******710*******720*******730*******740*******750*******760*******770*******780*******790*******800*******810*******820*******830*******840*******850*******860*******870*******880*******890*******900*******910*******920*******930*******940*******950*******960*******970*******980*******990*******1000******1010******1020******1030******1040******1050******1060******1070******1080******1090******1100******1110******1120******1130******1140******1150******1160******1170******1180******1190******1200******1210******1220******1230******1240******1250******1260******1270******1280******1290******1300******1310******1320******1330******1340******1350******1360******1370******1380******1390******1400******1410******1420******1430******1440******1450******1460******1470******1480******1490******1500******1510******1520******1530******1540******1550******1560******1570******1580******1590******1600******1610******1620******1630******1640******1650******1660******1670******1680******1690******1700******1710******1720******1730******1740******1750******1760******1770******1780******1790******1800******1810******1820******1830******1840******1850******1860******1870******1880******1890******1900******1910******1920******1930******1940******1950******1960******1970******1980******1990******2000******2010******2020******2030******2040******2050******2060******2070******2080******2090******2100******2110******2120******2130******2140******2150******2160******2170******2180******2190******2200******2210******2220******2230******2240******2250******2260******2270******2280******2290******2300******2310******2320******2330******2340******2350******2360******2370******2380******2390******2400******2410******2420******2430******2440******2450******2460******2470******2480******2490******2500******2510******2520******2530******2540******2550******2560******2570******2580******2590******2600******2610******2620******2630******2640******2650******2660******2670******2680******2690******2700******2710******2720******2730******2740******2750******2760******2770******2780******2790******2800******2810******2820******2830******2840******2850******2860******2870******2880******2890******2900******2910******2920******2930******2940******2950******2960******2970******2980******2990******3000******3010******3020******3030******3040******3050******3060******3070******3080******3090******3100******3110******3120******3130******3140******3150******3160******3170******3180******3190******3200******3210******3220******3230******3240******3250******3260******3270******3280******3290******3300******3310******3320******3330******3340******3350******3360******3370******3380******3390******3400******3410******3420******3430******3440******3450******3460******3470******3480******3490******3500******3510******3520******3530******3540******3550****

[dgtlmoon]

tgram has a max length

https://developers.cm.com/messaging/docs/telegram#:~:text=The%20maximum%20length%20of%20a,must%20be%20UTF%2D8%20encoded.

[leandertolksdorf]

@dgtlmoon This doesn‘t explain why the issue also occurs in the HTTP request. The link you provided also mentions a max length of 4096, why is the message then cut-off at 3557 characters?

[leandertolksdorf]

@dgtlmoon
I did some more investigation and found the bug:

The issue occurs when a tgram:// (or any other length-limited notification service's) url is defined alongside a free-length service (like get:// etc.).

That's because in the function notification.process_notification the original n_body, defined in line 127 gets truncated in line 188 for all notification urls instead of just the length-limited one.

# notification.py

def process_notification(n_object, datastore):
    # ...
    # Get the notification body from datastore
    jinja2_env = Environment(loader=BaseLoader)
    n_body = jinja2_env.from_string(n_object.get('notification_body', '')).render(**notification_parameters)
    # ...
        for url in n_object['notification_urls']:
        # ...
            if url.startswith('tgram://'):
                # ...
                n_body = n_body[0:body_limit] # ‼️ n_body is now permanently truncated
        # ...
        apobj.notify(
            title=n_title,
            body=n_body, # ‼️ The truncated n_body gets sent to the other notification urls, too
            body_format=n_format,
            # False is not an option for AppRise, must be type None
            attach=n_object.get('screenshot', None)
        )

[leandertolksdorf]

@dgtlmoon This is clearly a bug and unintended behavior. I'd be happy to fix this in a PR once I get to it but I don't think this issue should have been closed.

[dgtlmoon]

@dgtlmoon This is clearly a bug and unintended behavior. I'd be happy to fix this in a PR once I get to it but I don't think this issue should have been closed.

it would help if you wrote in your initital bug report that you are using a mix of notification methods, is that the real issue then? that when tgram:// is specified, that limit of body size is applied to all subsequent notifications?

yes PR's are appreciated - but please include a test case (you can modify/add the existing notifications test case)

[dgtlmoon]

@leandertolksdorf heya! when https://github.com/dgtlmoon/changedetection.io/actions/runs/9124493904 is finished, can you try pull and test the :dev tag container?