Bar Construction Recorder
Most traders only ever notice a bad bar by eye, long after the ticks that would explain it are gone. This EA keeps a running record of the comparison instead: on every tick it updates a locally tracked Open/High/Low/Close for the bar currently forming, and the instant a new bar starts, it compares the just-finished tick-built bar against the terminal's own reported bar for that same time slot (via iOpen/iHigh/iLow/iClose at the matching shift). A mismatch beyond the declared tolerance usually means one of two things: this terminal's tick feed missed ticks that the price feed actually had (a local gap), or the broker revised history after the fact (a server-side rebuild that changed the published bar after this EA had already tracked its own version). Either cause is worth a durable, timestamped record rather than a one-off visual impression. Every finished bar is logged - not only mismatches - so the CSV builds a continuous consistency record across the whole session, with the tick count behind each bar alongside both versions of its Open/High/Low/Close. Notes and limitations The tick-built Open is whatever price this instance of the terminal first observed for that bar - if this EA is attached mid-session, the very first bar it tracks may show a tick-built Open that starts later than the terminal's own bar Open, which was already forming before attach. This does not affect the High/Low/Close comparison used for the verdict. Comparison uses Bid only, matching MQL4's own bar-construction convention on most symbols; it does not separately track an Ask-based bar. A MISMATCH is evidence of a discrepancy, not a diagnosis - it does not distinguish a local tick gap from a broker-side history revision. Cross-check the terminal's own history against another data source when investigating a flagged bar. This EA never trades and never modifies an order - it only reads price data.
Expert advisor · MT4 · v1.0 · Free
About Bar Construction Recorder
Bar Construction Recorder is a script for MetaTrader 4. It can alert you with a pop-up, sound, email or push message. It has 3 settings, such as Tolerance points, Log file name and Alert on mismatch. MQL source code included.
Files in the download: BarConstructionRecorder.ex4, BarConstructionRecorder.mq4, BarConstructionRecorder.txt.
Settings
| Setting | Default | What it does |
|---|---|---|
| Tolerance points | 2 | Allowed High/Low/Close mismatch, in points, before flagging MISMATCH |
| Log file name | BarConstructionRecorder.csv | File written under MQL4\Files\ |
| Alert on mismatch | true | Turn this alert on or off |
How to install
- Download the ZIP from your PolyMaria library and unzip it.
- In MetaTrader 4 open File → Open Data Folder, then go to MQL4 → Scripts.
- Copy the .mq4 file(s) there. Put any .mqh files in MQL4 → Include.
- Open the .mq4 file in MetaEditor and press Compile (F7) if MetaTrader does not show it.
- Drag the script onto a chart to run it once.
Tags: Alerts · MT4 Expert Advisor · MQL4 Source Code