TMFetchPlugin

A generic HTTP / JSON fetcher plugin for TrafficMonitor. Point it at any REST API, write a one-line display template mixing literal text with $.path.x references, and the resolved value is rendered onto your TrafficMonitor taskbar / main window on a configurable schedule.

电量:$.battery.level% 状态:$.status -> 电量:76% 状态:OK

Multiple items are supported, each with its own URL / headers / body / template / interval / timeout.

Features

• Free-form display template. Just write text and drop $.path.x references inline. The scanner finds them greedily; everything else is literal. $$ emits a literal $. ${...} braces form is also accepted.
• Multi-line via \n. Templates with newlines are rendered through the plugin's own GDI draw path (IsCustomDraw + DrawItem), so each line gets its own row inside the same item slot. Single-line templates fall through to TrafficMonitor's default draw and inherit the user's TM theme/colours.
• JSONPath subset:.key, ['key'], [N] (negatives ok, e.g. [-1]), and ..key recursive descent.
• Per-item refresh on a background worker thread. The TrafficMonitor UI thread is never blocked, even on slow / failing endpoints.
• In-app options dialog with a live Test button: shows status, raw response, and the rendered template before you save.
• HTTP / HTTPS via WinHTTP — no runtime dependencies, no MSVC redist.
• Per-item method, headers, body, timeout.
• Hot-reload: edits to existing items take effect immediately.

Install

Grab the matching DLL from the latest release:

TrafficMonitor.exe	Use this DLL
32-bit / x86 (official build)	TMFetchPlugin-x86.dll
64-bit / x64	TMFetchPlugin-x64.dll

Drop the file into TrafficMonitor's plugins/ directory and restart TrafficMonitor. Then enable the items you want via 选项 → 插件管理 → TMFetchPlugin → 配置.

Bitness mismatch fails to load with 不是有效的 Win32 程序. Quick check of your TrafficMonitor.exe:

$b= [IO.File]::ReadAllBytes("path\to\TrafficMonitor.exe")
$o= [BitConverter]::ToInt32($b,60)
switch ([BitConverter]::ToUInt16($b,$o+4)) {
0x14c { "x86 (Win32)" }; 0x8664 { "x64" }
}

Build from source

Windows + C++17 compiler (MSVC recommended; MinGW also works).

# x86 (matches official TrafficMonitor.exe)
cmake -A Win32 -B build
cmake --build build --config Release
# x64
cmake -A x64 -B build64
cmake --build build64 --config Release

First configure auto-downloads the single-header nlohmann/json v3.11.3. Output DLL: build/Release/TMFetchPlugin.dll.

Configure

The in-app options dialog is the recommended path: every field is editable, and the Test button shows you the rendered output before you save.

Under the hood, settings live in TMFetchPlugin.ini inside TrafficMonitor's plugin config directory. Hand-editing is also fine:

[Plugin]Interval=10000 ; default refresh interval (ms)ItemCount=2 ; number of [ItemN] sections[Item0]Name=BTC Price ; shown in TrafficMonitor menusId=tmfetch_btc ; unique id (letters / digits / underscore)URL=https://api.coingecko.com/api/v3/simple/price?ids=bitcoin&vs_currencies=usd
Method=GET
Headers=Accept: application/json
; or split: Header1=Accept: application/json Header2=User-Agent: TMJsonPath=BTC: $$$.bitcoin.usd ; literal "BTC: $" + $.bitcoin.usdInterval=30000 ; per-item override (ms); 0 = use [Plugin] IntervalTimeout=8000 ; request timeout (ms)Body= ; optional request body (UTF-8) for POST/PUT

Full example with multiple items: examples/TMFetchPlugin.ini.

Display template syntax

The JsonPath field is the only value-formatting field. Write whatever text you want and inline $.path.x references; they're substituted with the value from the JSON response.

Template	Rendered
BTC: $$$.bitcoin.usd	BTC: $65432.5
电量:$.battery.level% 状态:$.status	电量:76% 状态:OK
电量:$.soc%\nF:$.front.psi R:$.rear.psi	row 1 电量:76%, row 2 F:230 R:240 (custom-draw)
★ $.stargazers_count	★ 4321
${$.bitcoin.usd}(legacy braces)	65432.5
(empty)	raw response body

Rules:

• $.path.foo is matched greedily; it stops at the first character that can’t be part of a path (whitespace, punctuation other than ./[).
• Inside brackets you can quote: $.users[0]['display.name'].
• ..key does a recursive descent and returns the first match.
• $$ emits a literal $. A bare $ followed by something that isn't ., [, or { is treated as a literal too (so $5 dollars works fine).
• A path that doesn't resolve renders as --.
• \n (or a real Enter in the options dialog) is preserved. When the rendered output contains a newline, the plugin switches to custom-draw mode and paints each line on its own row inside the item's slot.

Notes

• WinHTTP uses Windows' system proxy automatically.
• All network I/O happens on a dedicated worker thread — TrafficMonitor's UI thread is never blocked.
• Items survive config reloads in-place: removing an item from the dialog hides it but doesn't tear down the live IPluginItem* (TrafficMonitor caches those pointers, so destroying them at runtime would crash the host). Reordering / removing items takes effect cleanly after a restart.

License

MIT.